Apollo Flight Journal logo
Previous Index Next
Day 4, part 16: Rest and Preparation for Solo Operations Journal Home Page Day 5, part 18: Undocking & DOI, Snoopy goes solo

Apollo 10

Day 5, part 17: Snoopy prepares for the main event

Corrected Transcript and Commentary Copyright © 2012-2022 by W. David Woods, Robin Wheeler and Ian Roberts. All rights reserved.
Last updated 2022-02-12
Flight Plan page 3-53.
Planned Revolution 11 Events and Attitude.
095:56:03 Young (onboard): We've either got a hatch leak from somewhere, or it's not venting.
095:56:08 Stafford (onboard Snoopy): Let's recheck that.
095:56:09 Cernan (onboard Snoopy): Well, we're not losing pressure, John, that I can see.
095:56:14 Stafford (onboard Snoopy): [Garble] No-Go.
095:56:23 Stafford (onboard Snoopy): You want to go up there and go to Close on that valve, just to make sure it's closed?
095:56:27 Cernan (onboard Snoopy): If you want to try it go ahead. Maybe I could do it.
095:56:32 Stafford (onboard Snoopy): Can you reach it? Yes. You can do it.
095:56:36 Cernan (onboard Snoopy): There's a lot of crap in there though - see?
095:56:38 Stafford (onboard Snoopy): Yes. John, we're going to go to Close on this valve, just to lock it closed. Okay?
Stafford is advising Young that Cernan is going to put the LM docking hatch dump valve in the Closed position, to ensure it is really closed.
095:56:45 Young (onboard): Roger. Let's see if that does any good.
095:56:50 Cernan (onboard Snoopy): I tried to clean all that crap out of there, but I wouldn't be a bit surprised. Let's see; we - we should be losing pressure, because we don't have an Auto Repress until we get down to about 4.4 or 4.6, and we're already at 4 - 4.95.
095:57:07 Young (onboard): That thing is right now reading about 0.1.
095:57:14 Stafford (onboard Snoopy): That's 0.1 Delta-P?
Young is once again getting exasperated by the slow progress in venting the docking tunnel. The differential between the CM cabin pressure and that of the tunnel is still only 0.1 psia.
095:57:18 Young (onboard): Yes.
095:57:30 Young (onboard): Maybe some of that Mylar lodged in the vent thing, whatever vents it. I bet you a hundred dollars that's what's happened. How much do you want to bet?
095:57:58 Young (onboard): Hey, Tom.
095:58:13 Stafford (onboard Snoopy): Is it coming down at all, John?
095:58:14 Young (onboard): No. Not coming down at all.
095:58:20 Stafford (onboard Snoopy): No. Not coming down at all.
095:58:30 Young (onboard): Well, babe, I'm putting it on Vent.
Young is advising that he is returning the CM tunnel vent valve to the Vent position.
095:58:32 Stafford (onboard Snoopy): Was our gauge - Is our pressure going down?
095:58:35 Cernan (onboard Snoopy): No. We're venting into it and...
095:58:41 Stafford (onboard Snoopy): Vent seal - I checked the seal.
095:58:43 Cernan (onboard Snoopy): Look at all this crap in here. I tried to clean out that thing yesterday.
095:58:51 Stafford (onboard Snoopy): Do you hear air flowing?
095:58:56 Cernan (onboard Snoopy): You can't hear through here, though.
Stafford and Cernan are concerned that the LM docking hatch dump valve is not fully closed or the hatch seals are not sound. If so the LM cabin atmosphere will be leaking into the docking tunnel, maintaining its pressure.
095:59:17 Stafford (onboard Snoopy): I wonder if we'd overpressurize here a little bit if that would put us at Closed.
095:59:26 Cernan (onboard Snoopy): Let me try something. I'll try to build up a little bit.
095:59:30 Stafford (onboard Snoopy): John, we're going to try to overpressurize here - Just a little bit; not much.
095:59:37 Young (onboard): Okay.
095:59:38 Stafford (onboard Snoopy): Hey, John, I've got an idea.
095:59:40 Young (onboard): Yes?
095:59:41 Stafford (onboard Snoopy): It's kind of outsville.
095:59:42 Young (onboard): Yes.
095:59:44 Stafford (onboard Snoopy): If you could dump your cabin pressure down, say to 4 or 5.
095:59:47 Cernan (onboard Snoopy): No, let me build ours up, Tom.
095:59:49 Stafford (onboard Snoopy): Alright, we're going to go build ours up and see if that will help us ... seal, here.
095:59:53 Cernan (onboard Snoopy): Tell him, don't do anything until we help - build ours up.
Flight Plan page 3-54.
096:00:07 Cernan (onboard Snoopy): Alright, that's building up our - that's what I want to do.
096:00:13 Young (onboard): You all be careful over there now.
096:00:14 Stafford (onboard Snoopy): Okay, that should have it. That's plenty. Okay, our cabin pressure's up to 5.4.
096:00:20 Young (onboard): Okay.
096:00:21 Stafford (onboard Snoopy): Look at this stuff in here! That should be enough on Delta-P on that whole area to see if that's sealed. Now try to vent it.
096:00:32 Young (onboard): Okay. I've got it in Vent.
CM tunnel vent valve position, LM Vent.
096:00:43 Young (onboard): It's not doing it man.
096:01:15 Young (onboard): I put it in LM Press for a while. Maybe that will blow anything out of that hole if there's something in there.
With the CM tunnel vent valve in the LM Press position, the CM cabin atmosphere is vented into LM tunnel and with the LM overhead hatch vent valve open, pressurizes the LM cabin. This is used primarily as a procedure for pressurising the LM soon after departure from Earth or as a backup. Young is selecting this position in an attempt to clear any of the Mylar hatch insulation which may be blocking the valve.
096:01:20 Stafford (onboard Snoopy): Okay. We've pumped ours up to 5.3 - to 5.4 Delta-P.
096:01:40 Cernan (onboard Snoopy): We can probably continue. Tom.
096:01:44 Stafford (onboard Snoopy): Yes.
096:01:46 Cernan (onboard Snoopy): Let's go ahead.
096:01:49 Stafford (onboard Snoopy): Okay.
096:01:50 Young (onboard): [Garble.] What time is it getting to be? Are we behind?
096:01:52 Stafford (onboard Snoopy): It's 96 hours.
096:01:55 Young (onboard): Well, we're getting behind.
096:01:56 Stafford (onboard Snoopy): Yes. Except we have about a 20-minute pad on all the stuff.
The LM crew are pressing on with the PGA (Pressure Garment Assembly) pressure integrity checks.
LM ECS controls locations.
Oxygen Control Module.
Suit Gas Diverter Valve (situated above the Oxygen Control Module).
Suit Circuit and Canister Controls.
096:01:59 Young (onboard): Yes.
096:02:01 Cernan (onboard Snoopy): Okay, let's go on. Tom. Suit Gas Diverter Valve, Pull-Egress.
Pulling the Suit Gas Diverter Valve (control above the oxygen control module) out to the Egress position prevents gas in the suit circuits from passing into the LM cabin.
096:02:05 Stafford (onboard Snoopy): Okay. Go.
096:02:07 Cernan (onboard Snoopy): Cabin Gas Return, Egress.
With the Cabin Gas Return valve (on the suit circuit and canisters control module) in the Egress position, the valve is closed, ensuring suit circuit integrity during unpressurized cabin operations.
096:02:10 Stafford (onboard Snoopy): Go.
096:02:11 Cernan (onboard Snoopy): Suit Circuit Relief, Closed.
With the Suit Circuit Relief valve (on the suit circuit and canisters control module) in the Closed position, this overrides the Auto mode in which the valve responds to an aneroid device which measures the suit circuit pressure.
096:02:13 Stafford (onboard Snoopy): Go.
096:02:14 Young (onboard): Tom, I've got an idea.
096:02:17 Stafford (onboard Snoopy): Go ahead, John.
096:02:18 Young (onboard): I'm going to maneuver over to the attitude in Press, then roll.
096:02:23 Stafford (onboard Snoopy): Okay.
Young is confirming that he will leave the LM tunnel vent valve in the LM Press position whilst manoeuvring to landmark tracking attitude, as he is still trying to clear the valve.
096:02:24 Cernan (onboard Snoopy): Pressure Reg A. Closed.
096:02:27 Stafford (onboard Snoopy): I want to get this loose here a little bit. Press Reg A. Closed.
096:02:41 Cernan (onboard Snoopy): Okay. Closed.
096:02:42 Stafford (onboard Snoopy): Closed.
Putting the Press Reg A valve (on the oxygen control module) in the Closed position, allows the Press Reg B valve to be used in the Direct O2 position to build up the suit pressure as part of the PGA pressure integrity check the crew are carrying out.
096:02:43 Cernan (onboard Snoopy): Okay. Pressure Reg B, build the suit pressure up to - Wait a minute - to 8.85, and then we'll monitor for a decay.
096:02:50 Stafford (onboard Snoopy): Okay, coming up.
096:02:55 Young (onboard): Roll zero, pitch 270.
Young is confirming that they have manoeuvred to the landmark tracking attitude of 0° roll, 270° pitch, 0° yaw. This maneuver should have occurred at 95:25:00 GET.
096:03:02 Stafford (onboard Snoopy): Starting up.
096:03:15 Cernan (onboard Snoopy): Oh, shit.
096:03:25 Stafford (onboard Snoopy): Yes. If that isn't brown, I don't know what is.
096:03:28 Cernan (onboard Snoopy): That is. Yes.
096:03:45 Young (onboard): Hey, I'm sorry, you guys. I didn't have no control over that.
096:03:49 Stafford (onboard Snoopy): What's that?
096:03:51 Cernan (onboard Snoopy): Yes, I thought, we were really wheeling around there when I saw us move.
The crew have just experienced roll oscillations of up to 1 deg/sec. The problem was described by John Young in the Postflight Crew Debrief.
Young, from the 1969 Technical debrief: "We were told not to maneuver to a landmark tracking attitude. We could not vent the tunnel. We were told prior to this time, not to do any roll maneuvers, to deactivate the roll jets, and not to do any roll maneuvers until we vented the tunnel. At this time, we were LOS and we could not vent the tunnel. So nevertheless, the attempt was made to stick with the timeline, and we attempted to maneuver to the roll attitude. Unfortunately, it (the CSM) has been operating in SCS (control) and (we) had neglected to (rate) cage the BMAGs which resulted in oscillations in roll, probably in excess of 1°/sec. I know we were in excess of 1°/sec and this resulted in the slippage of the (docking) ring, and I'd estimate the slippage of the ring to be 6° to 8°."
The BMAGs can be rate caged so that they only provide backup data. However Young had omitted to place them in this configuration.
From the Apollo 10 Mission Report: "The tunnel valve was placed to the tunnel vent position and recycled to Lunar Module/Command Module differential pressure; however, there was no indication of tunnel venting. Subsequently, during postflight inspection, it was discovered that an improper fitting had prevented tunnel venting. Because the differential pressure across the installed hatch was only 1 psi, the Command Module slipped slightly with respect to the Lunar Module when the Service Module roll thrusters were fired on one occasion. The roll jets were then disabled to prevent the possibility of further slippage between the two docking rings."
If the crew had been able to vent the tunnel to almost a vacuum, the differential pressure across the docking ring would have great enough to impede the slippage.
096:03:58 Stafford (onboard Snoopy): How we doing? We're 8.
The crew have reached step 8 of the PGA integrity check list. This step calls for the crew to monitor the PGA cuff gauge. When it indicates a pressure of 3.7 to 4.0 psig, they should close the Press Reg B valve.
096:04:00 Cernan (onboard Snoopy): Stand by.
096:04:01 Stafford (onboard Snoopy): Go. Close it.
096:04:04 Cernan (onboard Snoopy): You can close it.
096:04:05 Stafford (onboard Snoopy): Go.
The Press Reg B valve is now put into the Closed position.
096:04:06 Cernan (onboard Snoopy): Okay. Monitor it for 1 minute.
The crew now monitor the PGA pressure decay for 60 seconds, whist exercising the suit joints.
096:04:08 Stafford (onboard Snoopy): Okay.
096:04:22 Stafford (onboard Snoopy): Looks good.
096:04:25 Cernan (onboard Snoopy): I've got a minute going over here.
096:04:38 Cernan (onboard Snoopy): You closed Pressure Reg B, didn't you?
096:04:39 Stafford (onboard Snoopy): Yes.
096:04:44 Cernan (onboard Snoopy): What's your decay doing?
096:04:46 Stafford (onboard Snoopy): I'm down to 3.35...
The pressure decay should not exceed 0.3 psig.
096:04:48 Cernan (onboard Snoopy): Yes, I'm already decayed 0.15.
096:05:07 Stafford (onboard Snoopy): How much did you get on it ?
096:05:10 Cernan (onboard Snoopy): Okay, Tom, there was a decay of 0.2.
096:05:12 Stafford (onboard Snoopy): Yes, Okay.
096:05:18 Cernan (onboard Snoopy): Hey, leave it that way. Was CO2 Canister Select, Secondary?
096:05:21 Stafford (onboard Snoopy): Okay, ready?
096:05:23 Cernan (onboard Snoopy): Can you reach it?
096:05:24 Stafford (onboard Snoopy): Okay.
096:05:25 Cernan (onboard Snoopy): Secondary?
096:05:26 Stafford (onboard Snoopy): Yes.
The routing of suit circuit gases through the secondary LiOH canister to check its functionality and the pressure integrity of the circuit in this configuration.
096:05:29 Cernan (onboard Snoopy): Monitor cuff gauge...
096:05:30 Stafford (onboard Snoopy): Man! That son of a bitch went down.
096:05:33 Cernan (onboard Snoopy): Monitor cuff gauge for 1...
096:05:34 Stafford (onboard Snoopy): Okay. See, it had to fill up that volume back there.
096:05:36 Cernan (onboard Snoopy): Yes, okay. Monitor it for 1 minute here.
The PGA cuff pressure gauge is monitored for 60 seconds whilst exercising the suit joints, it should not drop by more than 0.3 psig.
096:05:38 Stafford (onboard Snoopy): Okay.
096:06:33 Cernan (onboard Snoopy): Okay, that's good.
096:06:35 Stafford (onboard Snoopy): Okay.
096:06:36 Cernan (onboard Snoopy): CO2 Canister Select, Primary?
Return the PGA gas circuit to the primary LiOH canister.
096:06:40 Stafford (onboard Snoopy): Okay. Got it.
096:06:46 Cernan (onboard Snoopy): Suit Circuit Relief Valve, Auto?
096:06:49 Stafford (onboard Snoopy): Okay.
096:06:51 Cernan (onboard Snoopy): Cabin Press Reg A and B, Cabin.
With the PGA pressure integrity check complete the Cabin Press Reg A and B are returned to the Cabin position to permit oxygen flow to the suit circuit to maintain a pressure of 4.8 psig. This is the normal position during pressurised cabin operations.
096:06:57 Stafford (onboard Snoopy): Okay. Cabin.
096:06:58 Cernan (onboard Snoopy): Cabin Gas Return, Auto.
In the Cabin Gas Return, Auto position, gas flow into but not out of the suit circuit is permitted.
096:07:03 Stafford (onboard Snoopy): Check.
096:07:06 Cernan (onboard Snoopy): Suit Gas Diverter Valve, Push-Cabin.
Pushing in the Suit Gas Diverter Valve to the Cabin position, permits gas in the suit circuit downstream of the flow-control valves to flow into the cabin.
096:07:12 Stafford (onboard Snoopy): Oh. Whew!
096:07:15 Cernan (onboard Snoopy): You push it ?
096:07:16 Stafford (onboard Snoopy): Yes.
096:07:19 Cernan (onboard Snoopy): You got to blow your nose on that one.
096:07:21 Stafford (onboard Snoopy): Yes.
096:07:22 Cernan (onboard Snoopy): Okay, Cabin Fan Control, Closed.
The Cabin Fan Control circuit breaker on panel 16 is Closed. This circuit breaker applies dc power to the ECS O2 pressure regulator valves (Press Reg A & B).
096:07:27 Stafford (onboard Snoopy): You want to turn that son of a bitch on.
096:07:32 Cernan (onboard Snoopy): Make sure it's the control , Tom.
096:07:33 Stafford (onboard Snoopy): Okay. Okay. Check.
096:07:33 Stafford (onboard Snoopy): Okay, verify CSM tunnel hatch Pressure Equalization and the Tunnel Vent valves Closed, and the tunnel vented. I guess we got to wait on this one, huh?
096:07:42 Stafford (onboard Snoopy): Well, no, you don't . All this does is just check the cabin Depress - Oh, yes, we do, because pressure will flow back in through here. This is as far as we can go.
096:07:57 Cernan (onboard Snoopy): We don't have to if that's closed.
096:07:59 Stafford (onboard Snoopy): No, but, see - The way this son of a bitch is built, this thing will just leak out and let air leak past. It's a flimsy [garble]...
096:08:05 Cernan (onboard Snoopy): That's right.
096:08:11 Stafford (onboard Snoopy): Hello, John. How are you doing over there?
096:08:13 Young (onboard): Roger; I'm coming around to attitude, but I still can't see any vent.
Young has still not had indication that the LM tunnel is venting.
096:08:18 Stafford (onboard Snoopy): Okay. The only thing I can think of - We've built our pressure up here, but it still won't vent any. I guess we'll have to wait until MSFN contact. We've got a decision to make here. If it won't vent, either you I can do it by dumping your cabin all the way - and that decision's going to be up to you - or else we'll just call the rendezvous off. It doesn't matter one way or the other. The main thing is to play it safe. Over.
096:08:42 Young (onboard): Well, I don't know that - tunnel venting or not venting is a call-off for the rendezvous. Will you -
096:08:47 Cernan (onboard Snoopy): I don't either, Tom.
096:08:49 Stafford (onboard Snoopy): John, if you release - if you release that tunnel pressurized, we're going off of here like a goddamn springboard, babe. We've got 5,000 pounds of force on that tunnel where we release that latch.
096:09:01 Young (onboard): Well, you ain't going anywhere until you get to the end of the latch [garble]. Right?
096:09:05 Cernan (onboard Snoopy): By that time it will be vented.
096:09:08 Stafford (onboard Snoopy): Yes.
The docking probe lies at the core of Apollo's mission mode, Lunar Orbit Rendezvous, because it is crucial that the LM and CSM be able to reliably dock, become like one spacecraft, then separate when required. Thus, it had to be removable, which only increased its complexity as a mechanism. These two images, brought to the journal's attention by Ulli Lotzmann, show the probe in its folded (first image) and deployed configuration.
Folded docking probe.
Deployed docking probe.
During a docking between the CSM and the LM, as the docking probe is retracted the extension latch engages by cam action. Prior to undocking, the probe is preloaded to 5,900 (± 200) pounds of tension to allow the subsequent unlatching of the 12 docking ring latches, and to maintain tunnel pressurization. Preloading is achieved by rotation of the torque shaft, which mates with the floating extension latch by an Acme-threaded screw, to move the extension latch in the aft direction. To ensure proper preload, the handle assembly contains a preset clutch limiter that allows the handle to slip, relative to the shaft, when the prescribed torque is achieved.
Docking probe extension latch and preload handle.
Docking probe schematic.
With the torque applied to the extension latch the pressure on the docking ring tunnel seals between the two spacecraft is maintained, ensuring that the tunnels atmospheric pressure can be retained. Following the preloading of the extension latch the 12 CM docking latches are released and retracted from their engaged position and cocked in preparation for the undocking and subsequent redocking. The cocking requires two full stokes of the latch handle on each latch.
Docking latches.
To initiate the undocking following the probe preloading and the docking latch retraction, the Probe Extd/Rel guarded switch in panel 2 is held in the Extd/Rel position until at least 5 sec after the LM has released. AC power is applied to the extend latch release solenoid, capture latch release motor and indicator. The probe is extended by a compression spring in its main cylinder. The 10-inch extension stroke working against CSM/LM inertia takes ~5 seconds. The retraction of the capture latches allows the LM to separate off the probe. The talkback indicator goes from grey to barberpole and then back to gray indicating full extension of the docking probe.
Docking probe extend/release switch - Panel 2.
Stafford is making the point that when the probe is extended, as the LM moves away during the 5 seconds the probe takes to reach its maximum extension, the tunnel will vent very quickly any remaining atmosphere. Young is correcting him, he believes the release will be a relatively sedate action, but he is concerned whether the docking probe may be damaged.
096:09:11 Cernan (onboard Snoopy): Let's see what we can do besides this. I'm going to turn the AGS on, Tom.
096:09:20 Stafford (onboard Snoopy): Go ahead. Keep going.
096:09:22 Young (onboard): It's sort of like opening the hatch against psi [garble] way.
096:09:28 Stafford (onboard Snoopy): Yes.
096:09:29 Young): Yes. I don't know if they want to do that to the probe or not, though.
096:09:32 Stafford (onboard Snoopy): That's what I was wondering. What's going to happen to the probe?
096:09:34 Cernan (onboard Snoopy): Stand by for a Master Alarm.
096:09:36 Stafford (onboard Snoopy): Okay.
096:09:38 Young (onboard): I'll bet you anything what's happened is that Mylar's gotten up in the...
096:09:53 Cernan (onboard Snoopy): Another Master Alarm.
096:09:56 Stafford (onboard Snoopy): Okay.
096:10:38 Young (onboard): I'll bet you anything what's happened is that Mylar's gotten up in the --
096:10:46 Stafford (onboard Snoopy): Yes, I'll bet the same thing. The Mylar's in that vent hole.
096:11:31 Cernan (onboard Snoopy): I'd wait on that one. That's so quick.
096:11:33 Stafford (onboard Snoopy): Yes.
096:11:47 Young (onboard): Hey, man, even if I vent my cabin, that ain't going to depressurize your tunnel.
096:11:52 Stafford (onboard Snoopy): Yes, if - if you would open the Pressure Equalization Valve on your hatch and vent that, that would do it.
A pressure equalization valve is installed in the centre of the forward CM tunnel hatch to equalize the pressure between the CM cabin and the LM tunnel. A hand crank is used for opening the valve from inside the CM cabin. The crank handle has two positions, at 90 or 45 degrees. The handle placed in either position, unlocks the valve. Approximately five turns of the handle extends (close) or retracts (open) the valve.
CM tunnel hatch pressure equalization valve.
096:12:02 Cernan (onboard Snoopy): We could do it...
096:12:04 Young (onboard): You'd probably never close it with all that Mylar in there.
Young is concerned about how much of the Mylar hatch insulation has found its way into the pressure equalization valve mechanism and whether the valve will be able to close.
096:12:06 Cernan (onboard Snoopy): We could do it, Tom - from this end.
096:12:08 Stafford (onboard Snoopy): How?
096:12:10 Cernan (onboard Snoopy): We could open...
096:12:11 Stafford (onboard Snoopy): We could depressurize from this end.
096:12:11 Young (onboard): Say again?
096:12:13 Cernan (onboard Snoopy): We could depressurize from this end. We've got to do that, anyway, for the - for our - our regulator check.
096:12:21 Stafford (onboard Snoopy): John, we could depressurize from this end.
096:12:24 Cernan (onboard Snoopy): Not all the way.
096:12:26 Young (onboard): That sounds like bullshit to me, Tom. Let's wait and see What the big boys say.
096:12:31 Stafford (onboard Snoopy): Okay.
096:12:41 Stafford (onboard Snoopy): Yes, we've got plenty of O2 in the rapid Repress capability. It would probably be better for us to depressurize from this end, John.
The LM Cabin Repress valve is a solenoid operated valve for cabin repressurization and emergency oxygen supply. As well as the Auto (solenoid operation) position, it also has Manual and Close positions. It is used to repressurize the LM crew cabin after deliberate decompression and provides emergency oxygen flow if the cabin is punctured. If the cabin is punctured and the diameter of the hole does not exceed 0.5 inch [12mm], the valve can maintain cabin pressure at 3.5 psia for at least 2 minutes, allowing the crew to return to closed-suit operations. The Cabin Repress valve is situated on the oxygen control module behind the LMP. When the Manual position is selected, the inlet valve opens establishing flow to the cabin. The flow rate depends on which tank is supplying the O2. If supplied by the GOX (gaseous oxygen) tank in the descent stage the flow is 4 lbs per minute maximum, from the ascent stage GOX tanks the flow is 8 lbs per minute.
Cabin Repress valve on ECS oxygen control module.
096:13:33 Stafford (onboard Snoopy): When do we acquire MSFN again?
096:13:38 Cernan (onboard Snoopy): 96:27
096:13:44 Young (onboard): Still reading zero, Tom.
096:13:48 Stafford (onboard Snoopy): Okay. In other words, you can't vent that thing at all.
096:14:35 Cernan (onboard Snoopy): As far as you're concerned, have we got a good platform now?
096:14:37 Stafford (onboard Snoopy): Yes. Beautiful.
096:15:01 Cernan (onboard Snoopy): Darn it.
096:17:07 Stafford (onboard Snoopy): I think it probably would be best for us to do it.
096:17:11 Cernan (onboard Snoopy): We could go down partway anyway, then build it up and then come down and.do our regulator check.
096:17:15 Stafford (onboard Snoopy): Yes.
096:17:20 Cernan (onboard Snoopy): We've got nothing to lose. If that thing gets clogged again - and doesn't hold pressure...
096:17:37 Stafford (onboard Snoopy): Looks like it's holding good now. And our Delta-P's above his.
Stafford is pointing out that the difference in pressure between the LM cabin and the docking tunnel is greater than that between the CM cabin and the tunnel. The LM cabin pressure is now greater than that in the CM.
096:18:01 Cernan (onboard Snoopy): Why don't you take some pictures while you're there?
096:18:18 Stafford (onboard Snoopy): Son of a bitch! This freaking purse keeps falling out. Didn't these people fit this stuff - they put it together. This is as useless as tits on a boar hog. Okay. What's our basic for color on the lunar surface? 5.6 at 250?
The purse was a temporary storage bag which was used extensively to transfer small items from the CM to the LM. However in zero-g it would not stay hooked on to its mounts in the LM.
Stafford a keen photographer, is asking Cernan to confirm the pre-mission prescribed f-stop and shutter speed for the Hasselblad 70-mm stills camera. They will take colour photographs of the lunar surface during the low level passes whilst the LM Snoopy performs its solo operations.
096:18:48 Cernan (onboard Snoopy): f:4 Tom.
096:18:49 Stafford (onboard Snoopy): That's black and white. That's black and white.
096:18:53 Cernan (onboard Snoopy): Oh, color? Okay, wait a minute. I'll get it to you. I have it right here.
096:19:10 Cernan (onboard Snoopy): What do you want, color?
096:19:11 Stafford (onboard Snoopy): Color, lunar surface.
096:19:12 Cernan (onboard Snoopy): f:8 at 250th.
096:19:26 Stafford (onboard Snoopy): Well isn't that nice. Each one of these magazines you got to crank like that. And how do you get it with your gloves on? Beautiful. Absolutely beautiful.
096:19:43 Cernan (onboard Snoopy): I thought they were all supposed to be ready to go the minute you put them in there.
096:20:00 Stafford (onboard Snoopy): It doesn't work. Come on now. You son of a bitch!
096:20:13 Young (onboard): Tom, I reseated my - I reseated mine.
096:20:23 Cernan (onboard Snoopy): Still no vent, huh?
096:20:25 Young (onboard): Yes, you say your cabin's up at 5.4 [psia]?
096:20:30 Cernan (onboard Snoopy): Heck, yes. When we pumped it up, it stayed there.
096:20:47 Cernan (onboard Snoopy): We could even go a little higher.
096:20:52 Young (onboard): It could be leaking from here, but I checked my - I checked my - vent valve. I closed it and looked to see if it was sealed or not. The oxygen [garble] is locked. [Garble] I don't know what the heck it is, you guys. We get AOS here in a couple of minutes and then we can find out, I guess.
096:21:19 Cernan (onboard Snoopy): Yes, we're sitting, crossing our fingers right now.
096:21:24 Stafford (onboard Snoopy): Well, this back doesn't work; that's nice.
096:21:25 Cernan (onboard Snoopy): At all?
096:21:26 Stafford (onboard Snoopy): No.
096:21:27 Cernan (onboard Snoopy): Sure?
096:21:28 Stafford (onboard Snoopy): Well, take it out now [garble]. The camera works. She just don't work. [Garble.]
096:21:49 Young (onboard): I believe you could dump your [garble]; maybe if you could just dump it to like 2.5 or something like that, that would be good enough.
096:21:56 Cernan (onboard Snoopy): That's what we were thinking of. Let's wait now until we talk to MSFN, I guess.
Young is suggesting that if the LM cabin pressure was vented down to a pressure of 2.5 psia, through the front hatch vent valve, with the LM tunnel hatch vent valve open, this would reduce the docking tunnel pressure to an acceptable level for the undocking. Cernan wants to wait for confirmation of the procedure by MCC-H once they have AOS.
096:23:08 Stafford (onboard Snoopy): Hey, it won't work with the backs, Gene - o. It works by itself, but it won't work with the backs.
096:23:45 Cernan (onboard Snoopy): John, what - what angle are you at, so I can try and acquire.
096:23:56 Stafford (onboard Snoopy): (Laughter) Won't work, Gene - o. Just beautiful.
096:24:00 Young (onboard): Roger. I'm about 300 degrees right now.
096:24:01 Cernan (onboard Snoopy): Without the back, huh?
096:24:03 Stafford (onboard Snoopy): And both of them - I've turned them, and cranked them and cranked them and turned them.
096:24:07 Cernan (onboard Snoopy): Both - both magazines. You got to be kidding.
096:24:11 Stafford (onboard Snoopy): I'm not kidding.
096:24:12 Cernan (onboard Snoopy): There's one more magazine there. Something's got to be wrong.
096:24:16 Stafford (onboard Snoopy): You're right, babe. Something's got to be wrong. We're all squared away. It works fine without the back. I've turned it.
096:24:25 Cernan (onboard Snoopy): Let's see it once.
096:24:28 Stafford (onboard Snoopy): Have at it. It shows you the direction to rotate.
096:24:54 Stafford (onboard Snoopy): It just doesn't work. No, it was - the lenses were on good, but I checked - it works beautiful without the back. Beautiful without the back.
096:25:17 Cernan (onboard Snoopy): Give me the screen for it.
096:25:47 Young (onboard): ... shit!
096:25:48 Stafford (onboard Snoopy): I've done everything. You can tell when it works without it.
096:25:53 Cernan (onboard Snoopy): Did you try a different back.
096:25:55 Stafford (onboard Snoopy): That makes the second back.
096:25:59 Cernan (onboard Snoopy): Let me see. Try the third back.
096:26:09 Stafford (onboard Snoopy): [Garble] third back yet.
096:26:12 Cernan (onboard Snoopy): Oh. I guess it's in here.
096:26:21 Stafford (onboard Snoopy): Roll it.
096:25:23 Cernan (onboard Snoopy): [Garble] anything to it. What is that, black and white?
096:26:25 Stafford (onboard Snoopy): Yes. See.
096:26:39 Stafford (onboard Snoopy): It works good now. Now to get the color to work.
096:27:06 Cernan (onboard Snoopy): Hello, John, are you at any - What angles are you at? Are you...
096:27:11 Young (onboard): I'm at 300 degrees.
Cernan is enquiring what the current CSM HGA steering angles are. Young's response is that the HGA yaw angle is 300°. Cernan is trying to ascertain which spacecraft will have the best communications with MCC-H at AOS. At AOS the LM will be using an omnidirectional antenna.
096:27:20 Cernan (onboard Snoopy): Okay, you'll have better contact, because we'll be in Omni; so you go ahead and tell them, and tell them - maybe we could vent down here, and get that thing vented, and then build our pressure back up.
096:27:31 Young (onboard): Roger. Roger. I can't - we can't get the tunnel to vent. Over. We've pinned down Charlie Brown. Over. I've checked the vent valve, and - Roger. I'll say it again. We cannot get the tunnel to vent. Over.
From the Apollo 10 Mission Report: "The pressure in the tunnel between the Command Module and the Lunar Module could not be lowered to ambient pressure through the tunnel vent system. Post flight inspection of the vent system revealed that an incorrect fitting had been installed on the vent (see figure below). The proper part was specified in the installation procedures."
Command Module tunnel vent system.
To explain further, fitting at the end of the pipe which ought to have vented tunnel air to a vacuum should have had a collection of holes to allow the air out. The incorrect, but installed fitting had no such holes.
Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
This is Apollo Control 96 hours, 27 minutes Ground Elapsed Time. We should have acquisition now with Apollo 10 coming on the front side of the Moon in revolution 11. During this rev the crew of Apollo 10 will be preparing for undocking the Lunar Module from the - there goes a call now.
096:27:39 Duke: Hello, Charlie Brown. Houston. We're standing by. Over.
096:27:53 Young: Houston, Charlie Brown. Over.
096:27:57 Duke: Roger, Charlie Brown. Read you...
096:27:58 Young: I checked the vent valve and...
096:28:07 Young: Roger. I say again, we cannot get the tunnel to vent. Over.
096:28:12 Duke: Roger. Understand. Tunnel will not vent.
096:28:17 Young: That's correct. We've checked the inflow valve; I've checked the inflow valve; I've checked the vent valve. And Tom and Gene have checked their Auto valve and their hatch seal around the hatch, and they feel some pressure inside their vehicle. And it doesn't appear to be leading into the tunnel, so I don't know what their problem is. Possibly some of that insulation has gotten lodged in the vent line, maybe.
096:28:52 Duke: Roger. We copy. Stand by.
096:29:07 Young: This is Charlie Brown. Do you read? Over?
096:29:10 Duke: Roger. We read you five-by - about three-by, Charlie Brown. We copied that the tunnel will not vent, so we're working the problem now. Stand by. Over.
096:29:15 Young: We can barely read you now.
096:29:17 Duke: What's your problem there? [Garble.]
096:29:22 Stafford (in Snoopy): Houston, this is Snoopy. How do you read?
096:29:29 Duke: Snoopy, this is Houston. We read you about two-by.
096:29:32 Stafford (in Snoopy): Okay. John's already described the problem, and we recommend that from what we can see up here, we're sure that Mylar insulation has plugged up up his vent line to vent the tunnel. We can vent it through the LM and go hard suit through here and repressurize this spacecraft. And we would recommend that action, rather than having the CSM depressurize. Over.
096:30:10 Duke: Snoopy, Houston. You're unreadable. We copied a few words about the Mylar insulation and that the tunnel will not vent. Otherwise, that's all we can copy. Over.
096:30:20 Cernan (onboard Snoopy): Hey, Let me talk to him. [Garble.]
096:30:23 Stafford (onboard Snoopy): Sure.
096:30:24 Cernan (in Snoopy): Hello, Houston. How do you read Snoopy now?
096:30:28 Duke: You're about two-by, still, Gene.
096:30:34 Cernan (in Snoopy): Okay. If we have to, we would like to go ahead and try and vent the tunnel through the LM. We will depressurize the LM part way and try and vent the tunnel part way, and then build the LM back up. How does that sound?
096:30:48 Duke: Roger. Stand by.
096:31:00 Stafford (onboard Snoopy): [Garble] this to work. You have to keep turning and...
096:31:03 Cernan (onboard Snoopy): Yes, that's what I did. Just turn the mother.
096:31:27 Stafford (onboard Snoopy): Shit, now I can't...
096:31:29 Cernan (onboard Snoopy): Tom, we ought to try and get a - We're waiting for [garble] landmark tracking, so we can't get a state vector. I can't go ahead with any more AGS work.
096:31:49 Duke: Hello, Snoopy and Charlie Brown. We recommend you skip the landmark tracking and jump to a high gain antenna attitude. Over. We'll have you some angles momentarily.
096:32:06 Stafford (onboard Snoopy): Yes.
096:32:31 Duke: Hello, Charlie Brown. Houston. If you maneuver to a 000 roll, 014 pitch, and yaw 000, and get into high gain, your angles are good in the Flight Plan. Snoop, your angles are good as listed in the Flight Plan at 97 hours. Over.
096:32:50 Cernan (onboard Snoopy): [Garble] still can't lock S-band.
096:32:52 Cernan (in Snoopy): Snoopy. Roger. Understand.
096:32:53 Young: What did they say Geno?
096:32:57 Cernan (in Snoopy): They said if you maneuver to those angles, your high-gain angles are good as in the Flight Plan, and ours our good at 97 hours.
096:33:07 Duke: Roger, Snoop. Your angles are 193 and yaw 64 degrees on the high gain antenna when Snoopy gets - correction, when Charlie Brown gets the attitude.
096:33:11 Young (onboard): What angles? My Flight Plan says Omni Antenna C.
096:33:15 Cernan (in Snoopy): Houston, repeat up to me where you want Charlie Brown to maneuver to? He can't read you.
096:33:28 Stafford (in Snoopy): In the angles.
096:33:29 Duke: Roger, Snoop. We want Charlie Brown to maneuver to 000 roll, pitch 014, yaw 000. It's listed in the Flight Plan at 96 hours and 40 minutes. Over. Skip the landmark tracking.
096:33:50 Young: Okay skip. Understand skip the landmark tracking. Roger.
096:34:07 Stafford (in Snoopy): Say, I asked you what angles. What do you want for Snoopy and Charlie?
096:34:11 Cernan (onboard Snoopy): Got them already, Tom.
096:34:35 Duke: Charlie Brown/Snoop, let us know when you get there.
096:34:42 Young (onboard): Roger. We're, we're on our way.
096:34:45 Cernan (in Snoopy): Okey doke. This way we get high gain so we can get our state vector update and continue on. We can't do much without that state vector.
096:34:55 Duke: Roger, Snoop. We copied about - We see Charlie Brown maneuvering to high gain attitude. Stand by on the tunnel vent. Over. We're coming up with a procedure for you.
096:35:10 Cernan (in Snoopy): Okay. Great. Thank you.
096:35:59 Young: Okay, Tom. LM time is going to be about 360, right? 606 36 360 and roughly 40 above 400. Right?
096:36:15 Stafford (in Snoopy): Yes. Hey, how come you're feeding on the VOX through feed loop? Are you VOX?
096:36:21 Young: No. We got a hot S-band mike when we're in ICS PPT and Downvoice Backup.
Young is referring to the Inter Communications System umbilical switch using it in the intercom/PTT mode. In this mode a 'hot mike' (constantly open mike) is provided for the intercom loop. The S-Band AUX switch on panel 3, when in the DN Voice BU position, selects the PM (Pulse Modulation) baseband voice mode for the transponder selected using the S-Band Normal XPNDR switch (panel 3) in the Prim or Sec position.
S-Band Aux switch - Panel 3.
096:36:25 Stafford (in Snoopy): Okay.
096:36:27 Young: I just left it there right now.
096:36:29 Stafford (in Snoopy): Alright. So the ground is reading us full time, when we transfer.
096:36:33 Young: Right in this mode, they are. Yes.
096:36:35 Stafford (in Snoopy): Okay.
096:36:44 Young (onboard): Okay, Geno. We'll have to keep this up a little here. I'll pitch a little faster.
096:36:49 Cernan (in Snoopy): Okay, babe.
096:37:00 Young: Okay, that's off, and we'll check it.
096:37:22 Young (onboard): Okay, Geno. We got 25 degrees to go.
096:37:24 Duke: Snoopy, Houston.
096:37:28 Stafford (in Snoopy): Go ahead, Houston. Snoopy. Over.
096:37:31 Duke: Roger. Houston. You're coming about three-by now, Tom. When we get high gain lockup, we'd like voice with the ranging off. Over.
096:37:39 Stafford (onboard Snoopy): Down Voice Backup.
096:37:41 Cernan (onboard Snoopy): Say again there, Houston...
096:37:45 Stafford: (in Snoopy): Down Voice Backup ranging off.
096:37:49 Cernan (onboard Snoopy): Houston, how are you reading Omni now?
096:37:51 Duke: Roger. And in Down Voice Backup master, if you turn the ranging Off, we'll probably improve the voice quality some. Over.
096:38:02 Cernan (in Snoopy): Okay, Charlie. I've got the ranging off.
Duke is suggesting that the S-Band Functions Range switch on panel 12, be placed in the Off/Reset position as this inhibits range data transmission to MCC-H as this may be interfering. See full function explanation at 082:52:29.
S-Band Functions Range switch - Panel 12.
096:38:06 Duke: Roger. You're a little bit better, Gene-o. Charlie Brown, I understand you're calling. Go ahead. Over.
096:38:18 Young (onboard): Okay, Gene-o. We got 25 degrees to go.
096:38:26 Cernan (onboard Snoopy): Okay, John. Understand 25 degrees to go.
096:38:33 Stafford (onboard Snoopy): Houston, this is Snoopy. How soon on a solution on this tunnel? Over.
096:38:44 Young (onboard): I don't think they're reading us, Tom.
096:38:52 Stafford (in Snoopy): Hello, Houston. This is Snoopy. How do you read? Over.
096:38:56 Duke: Go ahead, Snoop. Over.
096:38:58 Young: I'll have my high gain in a minute.
096:39:23 Young: Okay, ... that I could read ...
096:39:39 Stafford (in Snoopy): Looks like he's about there.
096:39:43 Stafford (in Snoopy): Hello, Houston, this is Snoopy. Do you read? Over.
096:39:50 Duke: Go ahead, Snoop.
096:39:52 Stafford (in Snoopy): Okay, Charlie. Look, as far as we can see, it still appears to us like all this Mylar floating around in the spacecraft has probably got into that vent line. The only solution we see about it is we vent the tunnel and take it out through the LM and take us down. With Charlie Brown good it will stuff that Mylar right back into his valve - tunnel valve, which is no good. We'll have a rough riding Command Module, but if we did do something, we could live with the LM for a while. But that's about all we can see. And as far as we understand about the probe, it's probably not a good idea to release that probe until we've depressurized. Over.
CDR Stafford is suggesting that to vent the docking tunnel, they should open the LM overhead hatch vent valve and the vent valve on the LM front hatch, venting through the LM cabin. Once the tunnel has vented, both valves would be closed and the LM cabin brought back up to normal pressure prior to undocking.
096:40:41 Duke: Roger, 10. Correction. Roger, Snoop. We're aware of that. We will probably come up with that solution. The only thing about releasing the probe without doing a hatch integrity check, we're a little concerned about that. If you'll stand by a couple of minutes, we'll come up with a procedure for you for venting the tunnel. Over.
096:41:04 Stafford (in Snoopy): Okay.
096:41:07 Young: Houston, Charlie Brown on the high gain. How do you read?
096:41:12 Duke: Hey, you're coming about three-by, John.
096:41:17 Young: Roger. I'm reading you loud and clear now.
096:41:19 Duke: Okay. You're coming about four-by. You're picking up all the time.
096:41:20 Cernan (in Snoopy): Houston, how is Snoopy on high gain?
096:41:24 Duke: Hey, Snoopy, you're five-by. Stand by.
096:41:26 Cernan (in Snoopy): How is Snoopy on high gain?
096:41:28 Duke: You're five-by, Snoop. Stand by.
096:41:33 Cernan (in Snoopy): Standing by, babe.
096:41:41 Stafford (onboard Snoopy): [Garble] You can have these feedback loops.
096:41:44 Cernan (onboard Snoopy): You can hear it coming down and going back up again.
Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
096:42:21 Stafford (onboard Snoopy): [Garble] descent O2.
096:43:55 Young: Okay, Snoopy. You want to do another LM drift check now?
096:44:01 Stafford (in Snoopy): Yes. Let's get ahead of them while they're still figuring what their recommendations are. John, on my mark, let's do a Verb 06, Noun 20. We'll try to keep ahead of it while we can.
096:44:12 Young: Roger. Go ahead.
096:44:16 Stafford (in Snoopy): Okay. Counting down on Verb 06, Noun 20: 3. 2. 1.
096:44:21 Stafford (in Snoopy): Mark it.
096:44:23 Young: Roger. Plus two balls 167, plus 01380, plus three balls 94.
096:44:38 Stafford (in Snoopy): Roger. 00167, 01380, 00094. Over.
The crew are transferring the ICDU angles. (See detailed explanation at 095:00:03.) The angles passed from Young to Stafford are Roll, 001.67°; Pitch, 013.80°; Yaw, 000.94°.
096:44:45 Young: Got them.
096:44:47 Stafford (in Snoopy): Okay.
096:45:08 Stafford (in Snoopy): Okay, Houston. My reading 0620 [Verb 06 Noun 20], plus 30186, plus 19360, plus 35913. Over.
The ICDU angles for the LM following conversion to take account of the differing orientations of the two spacecraft are Roll, 301.86°; Pitch, 193.60°; Yaw, 359.13°.
096:45:22 Duke: Roger. We copy. Snoop, Cap - Snoop, Houston. We'd like to uplink a - got a load for you, if you'll give us P00 and Data. And we'll have some word on the tunnel procedure momentarily. Over.
096:45:40 Cernan (onboard Snoopy): [Garble] Tom.
096:45:51 Stafford (in Snoopy): Roger. We're in P00 and Data. You got it.
096:45:54 Duke: Roger.
096:46:09 Cernan (onboard Snoopy): Are we doing the drift check now?
096:47:09 Young: Houston, this is Charlie Brown. I never did get that DAP load. You got one for me? Over.
096:47:14 Duke: Roger. We got it here for you, Charlie Brown, if you're ready to copy. CSM weight is 36688; gimbal trim: pitch minus 0.73, yaw plus 0.82; LM weight 31117. Over.
096:47:46 Young: Roger. CSM weight 36688; minus 73, plus 82; LM weight 31117.
096:47:54 Duke: Roger.
096:47:58 Young: How do you want DAP set up today to balance these quads?
096:48:03 Duke: Stand by. Use a BD roll, Charlie Brown.
096:48:13 Young: Say again. Over.
096:48:15 Duke: Roger. Use BD roll.
096:48:21 Young: Roger. Use BD.
Duke has passed up details of the variables that must be incorporated into the upcoming CSM DAP load. The weights of both spacecraft: CSM, 36,688 pounds (16,680 kg) and the LM, 31,117 pounds (14,147 kg); the SPS gimbal actuator pitch angle, -0.73°; gimbal actuator yaw angle, +0.83°. He also passed up that the Roll RCS motors on SM quads B and D should be used whilst under the control of the digital autopilot. See explanation of DAP load at 075:47:35.
096:48:26 Cernan (in Snoopy): Houston, Snoop. Are you done?
096:48:29 Duke: That's negative, Snoop.
096:48:31 Cernan (in Snoopy): Never mind, I can see you're not. Have you got our DAP load on page 45?
096:48:38 Duke: That's affirmative. Coming up to you now. CSM weight 36688; LM weight 31117. Over.
096:48:55 Cernan (in Snoopy): Roger. LM is 31117; CSM is 36688. And understand the 501 and the 547 are still good.
Spacecraft weights (in pounds) are required for the LM DAP load.
The reference to 501 and 547 relate to the AGS (Abort Guidance Section), DEDA (Data Entry and Display Assembly) data insertion and data output memory addresses. The DEDA is a general purpose astronaut input-output device for the AGS located on the right-hand side of the LM cockpit, just under the LMP's window. It consists of a keyboard, electroluminescent address and digital data displays.
The procedure followed to enter data into the AGS, AEA (Abort Electronics Assembly) is as follows:
DEDA (Data Entry and Display Assembly).
The procedure followed to output data from the AGS, AEA (Abort Electronics Assembly) is as follows: The above procedures are further detailed in the LM/AGS Operating Manual Flight Program-6 (TRW, April 1969). Code 547 is a DEDA input relating to the lunar align azimuth correction. The input value is expressed as a octal expression of the angles radian value. Code 501 is a DEDA output relating to the velocity-to-be-gained in Y-body direction (- left or + right). The output value is expressed in feet per second.
096:49:05 Duke: Affirmative. Stand by. We'll be right with you, Snoop, on the [garble].
096:49:11 Cernan (in Snoopy): Okay. As soon as we get our load - Okay. We're going to proceed as soon as we get the computer back to updating the AGS, and going through the gimbal check until we hear from you.
096:49:23 Duke: Roger. We concur.
096:49:32 Duke: Snoop, Houston. We got just one more load to go and then we'll have it for you. Over.
096:49:40 Cernan (in Snoopy): Okey doke.
096:50:16 Cernan (in Snoopy): Hello, Charlie Brown. Snoop.
096:50:18 Young: Go ahead. Over.
096:50:19 Cernan (in Snoopy): On that VHF A, was your squelch all the way off?
096:50:23 Young: That's affirmative.
096:50:25 Cernan (in Snoopy): Okay.
096:50:29 Duke: I had the squelch up and down when you guys were transmitting. I couldn't do any good either way.
096:50:33 Cernan (onboard Snoopy): Okay.
096:52:34 Stafford (onboard Snoopy): Geno, I'm...
096:52:35 Cernan (onboard Snoopy): Yes.
096:52:36 Stafford (onboard Snoopy): ...I'm right over Diamond Back and Sidewinder.
096:52:38 Cernan (onboard Snoopy): Are you really?
096:52:39 Stafford (onboard Snoopy): Right over.
096:52:40 Duke: Hello, Snoop. Houston. We are through with the load. The computer is yours. Charlie Brown and Snoop, if you're ready to copy, we have a procedure for you for your tunnel vent. Over.
096:52:53 Cernan (in Snoopy): Roger. Go ahead.
096:52:57 Stafford (in Snoopy): Go ahead.
096:52:59 Duke: Roger, Snoop. On activation 38, we want you to do - to vent the tunnel using the normal - the regulator check with the following exceptions. Are you ready to copy? Over.
096:53:15 Stafford (onboard Snoopy): Go ahead. Are we still hot?
096:53:21 Cernan (onboard Snoopy): It's not hot, Tom.
096:53:22 Stafford (in Snoopy): Go ahead.
096:53:23 Duke: Okay. We assume you've gone through the regulator check, so we're going to shorten this procedure. In step 2 - step 2 on activation 38, line 2, verify overhead cabin dump valve.
096:53:35 Cernan (onboard Snoopy): Tell them we have it.
096:53:38 Duke: We want that Open. Cabin repress to Close. Activation, page 39, step 3; the forward Cabin Dump valve, Open, then Auto at 3.5 psi. Now, that will give us 1.5 Delta-P in the tunnel and at this time, CMP should be monitoring the LM/CM Delta-P. Now, all we're concerned about is the hatch integrity check for the command module using this procedure. We don't have to take the tunnel all the way down. Now we will have to eliminate the RCS hot fire, the yaw thruster firing, and we'll get that out of the way after undocking. Over.
096:54:32 Stafford (in Snoopy): Okay. I think we got it, Charlie. On page 38, step 2, verify overhead cabin dump valve to Open instead of Auto; cabin Repress to Close on step 3; opened at Auto at 3.5; and we'll restrict the yaw firing thruster as you're concerned about the Command Module hatch integrity check, and for us to assume that when he releases the probe, that the 3½ psi will not hurt the probe. Over.
096:55:02 Duke: That's affirmative. We've run that through the experts, Tom, and it will not hurt the probe or the drogue. In repressurizing, don't forget to put the overhead dump valve - overhead dump valve - back to Auto when you Repress. Over.
With the Cabin Relief And Dump Valve in the overhead hatch in the Auto position, it permits the valve to operate normally as an automatic pressure-relief device. The valve's aneroid sensor causes the valve to open at a pressure of 5.8 psia, bleeding excess cabin pressure.
096:55:20 Stafford (in Snoopy): Oh, yes. We know all about that, Charlie.
096:55:22 Duke: Okay. You just pressurize the tunnel back up again...
096:55:25 Stafford (in Snoopy): Okay. We're ready to go through it - We're ready to go. Right. We're ready to go ahead through it right now, when John's ready.
096:55:33 Duke: Roger. Now, we'd like you to stay...
096:55:35 Young: Okay. Let me get up here in the tunnel there, Tom.
096:55:38 Duke: We'd like you to stay - Okay, troops. Now we'd like you to stay at about three and a half for a couple of minutes so we can get a hatch integrity check in the Command Module. Over.
096:55:49 Stafford (onboard Snoopy): Let's start there, Gene-o.
096:55:50 Cernan (onboard Snoopy): Okay.
096:55:51 Stafford (in Snoopy): Roger.
096:55:55 Young: Okay. Go ahead, Tom. What position you want me to be on tunnel? Do you want me on CM Delta-P?
096:56:00 Duke: That's affirmative.
Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
096:56:05 Stafford (onboard Snoopy): I'm going [garble] to get [garble].
096:56:07 Young: Okay. Go ahead, Tom.
096:56:10 Cernan (onboard Snoopy): On what page?
096:56:11 Stafford (onboard Snoopy): Right here. Read it off.
096:56:14 Cernan (onboard Snoopy): We didn't do that regulator check, though.
096:56:16 Stafford (onboard Snoopy): No. we haven't done it; we're only going down to 3.5. Okay.
096:56:19 Cernan (onboard Snoopy): Cabin Gas Return, Egress.
Cabin Gas Return valve is situated on LM ECS Oxygen control module.
096:56:21 Young: Are you all doing the checks, you guys?
096:56:24 Stafford (in Snoopy): Stand by. Keep in touch.
096:56:25 Cernan (in Snoopy): We're starting it off right now, John. I'll give you a hack when we're going down. Cabin Gas Return, Egress.
096:56:27 Young: Thank you.
096:56:29 Duke: Snoop, Houston. You'd give us a warm feeling if you could talk us through this.
096:56:30 Stafford (onboard Snoopy): Cabin Gas Return, Egress.
096:56:37 Cernan (in Snoopy): Okay. Cabin Gas Return, Egress.
096:56:40 Stafford (onboard Snoopy): Okay, let me go back to - back to...
096:56:42 Cernan (in Snoopy): How do you read my VOX, Houston?
096:56:45 Duke: Reading you five-by, Snoop.
096:56:45 Stafford (onboard Snoopy): ...Did your suit start to flutter? Okay, [garble] ready.
096:56:48 Cernan (in Snoopy): Check. Cabin - Cabin Gas Return - Wait a minute. Wait a minute. Start here, babe, or back here?
096:56:57 Stafford (onboard Snoopy): No, we've already got - we've already got through all that.
096:57:03 Cernan (in Snoopy): Okay, Houston, starting at 96:05, step number 2. Is that correct?
096:57:06 Duke: That's affirmative. Before you get started, we want both Press Regs A and B to Egress. Over.
With the Press Reg valves A and B in the Egress position on the LM ECS Oxygen control module, regulated oxygen flow to the suits is maintained at 3.8 ±0.2 psia.
096:57:17 Cernan (in Snoopy): Both Press Regs A and B to Egress.
096:57:19 Young: I've got them Egress. Let's go.
096:57:21 Cernan (in Snoopy): Roger. They're Egress. Cabin gas return, Egress.
096:57:22 Cernan (in Snoopy): Verify overhead cabin dump valve, Open.
096:57:22 Stafford (onboard Snoopy): Okay.
096:57:27 Cernan (onboard Snoopy): Stand by, Overhead Cabin Dump valve, Open.
The overhead LM hatch cabin relief and dump valve is set to the Open position to vent the CM/LM tunnel atmosphere into the LM cabin.
096:57:32 Stafford (onboard Snoopy): Stand by.
096:57:37 Cernan (in Snoopy): Open?
096:57:38 Duke: Yes. That's affirmative.
096:57:39 Cernan (in Snoopy): Okay. Cabin Repress, Closed.
With the Cabin Repress valve in the Closed position, oxygen is prevented from flowing into the cabin from the manifold.
096:57:42 Duke: Go.
096:57:44 Stafford (onboard Snoopy): Okay.
096:57:47 Cernan (in Snoopy): Got it closed?
096:57:48 Stafford (in Snoopy): Okay.
096:57:49 Cernan (in Snoopy): Press Reg B, Egress. B Bravo. Okay?
096:57:55 Stafford (onboard Snoopy): Go.
096:57:58 Cernan (in Snoopy): Okay. Forward Cabin dump valve Open and in Auto at 3.5.
The forward cabin relief and dump valve has been set to the Open position to vent the cabin, and when the cabin pressure drops to 3.5 psia the crew will set in to the Auto position.
Cabin Relief and Dump valve situated on both LM hatches.
096:58:00 Stafford (onboard Snoopy): Okay, it's [garble]...
096:58:01 Cernan (in Snoopy): Why don't you get that, Tom, and I'll tell you when.
096:58:03 Stafford (in Snoopy): Okay, and I've got Press Reg A, Close; Egress, too. And this should be Pull to Egress, right?
096:58:10 Young (onboard): That's right.
096:58:11 Cernan (onboard Snoopy): I don't know. What'd I tell you? Wait a minute.
096:58:12 Stafford (onboard Snoopy): You didn't have...
096:58:13 Young: Okay. I'm reading a minus a half psi on my CM/LM pressure gauge right now.
With the LM/CM differential pressure meter on panel 12 reading minus 0.5 psi, this indicates that the LM tunnel pressure is 0.5 psia above that of the CM cabin.
As the LM cabin pressure has been increased in an effort to force open the vent valve in the docking tunnel the pressure in that tunnel now slightly exceeds the CM cabin pressure. The plan is now to dump the LM cabin pressure through the forward hatch, and the tunnel pressure should drop in line with the LM cabin.
096:58:22 Cernan (in Snoopy): Houston, where is the suit gas diverter valve on this? It's in Egress, that should be right.
096:58:26 Duke: Suit gas diverter valve should be in Egress.
With the Suit Gas Diverter pulled out in the Egress position, it prevents gas in the suit circuit from passing into the cabin.
096:58:30 Cernan (in Snoopy): That's what we figured.
096:58:31 Stafford (onboard Snoopy): Okay.
096:58:32 Cernan (in Snoopy): And just to verify, we got Press Reg A in Egress and Press Reg B in Egress. Is that correct?
096:58:39 Stafford (onboard Snoopy): Yes, that's right.
With the Pressure regulator valves A & B in the Egress position, it permits regulated oxygen flow to the suit circuit to be maintained at 3.8 psia ±0.2.
096:58:42 Duke: Affirmative.
096:58:46 Cernan (in Snoopy): Okay. We're going to start dumping the cabin down to 3.5.
096:58:50 Duke: Rog.
096:58:51 Young: Do it slowly, babe.
096:58:53 Cernan (in Snoopy): Okay. There's 5.
096:58:58 Young: Okay. I have a half a psi.
The docking tunnel pressure has now dropped to 0.5 psia below that of the CM cabin, as the LM cabin pressure is reduced.
096:59:00 Cernan (in Snoopy): 4.8, 4.5. 4.2.
096:59:06 Young: Okay. I have 1 psi.
Docking tunnel pressure is now 1 psi below the CM cabin pressure.
096:59:07 Cernan (in Snoopy): 4.0. 3.8. [Garble.] Hold it. 3.5. Stop it, Tom. Okay. We're down to 3.5 and our suits are 4.2.
096:59:17 Young: At 1.5 psi.
096:59:20 Duke: Roger. Snoop, we copy. 3½ psi. And we copy Charlie Brown, 1½ psi. Now hold - Let's hold for a couple of minutes to get a hatch integrity check. Charlie Brown, watch your cabin pressure. Over.
096:59:35 Young: Yes, I'm watching her.
The CM cabin is now 1.5 psi above the docking tunnel. The venting of the LM cabin has dropped its pressure to the desired 3.5 psi. The LM cabin venting will now stop so that the John Young can check that this pressure differential is maintained, which will indicate that the CM tunnel hatch pressure seal is sound and no leaks are present.
096:59:44 Cernan (in Snoopy): This is like spring in Chicago in here. There's snow all over the place.
Particles of the Mylar insulation from the CM tunnel hatch have been stirred up by the movement of the LM cabin atmosphere as it is vented through the forward hatch.
096:59:48 Duke: Rog.
Flight Plan page 3-5.
097:00:07 Cernan (in Snoopy): Hey, Tom. I'm going ahead with the AGS bit while I can.
097:00:08 Young (onboard): Okay good.
097:00:35 Young: Okay. What's you guys' pressure, there?
097:00:45 Duke: Snoopy, you holding your 3½?
097:00:46 Young: [Garble.]
097:00:46 Stafford (in Snoopy): Okay. I think it's starting to build up which meant the tunnel pressure's built - yeah, it's started to go up to 4.
097:01:03 Young: Okay. Mine's down to 1, now.
097:01:05 Cernan (in Snoopy): Houston, did you read Snoopy? Our pressure went from 3½ up to 4, and then Tom just closed the Overhead Dump valve.
097:01:13 Duke: Roger.
097:01:14 Young: Okay. Mine's holding at 1 right now.
097:01:17 Young: That's because they built theirs up, I guess.
The CM/LM tunnel differential pressure has reduced slightly, not as a result of the CM tunnel hatch leaking, but rather because the LM cabin pressure has increased by 0.5 psi and as the tunnel is being pressured from the LM cabin, its pressure has also increased by the same amount.
097:01:19 Duke: Charlie Brown and Snoop, we are satisfied with the hatch integrity check and the CSM. Now, before - Snoop, before you repressurize, go to Cabin Gas Return to Cabin. Over.
097:01:31 Cernan (in Snoopy): Roger. Cabin Gas Return to Cabin.
Duke has is mistaken in his instruction, it should read Cabin Gas Return to Auto. This requires clarification by Duke.
097:01:34 Duke: Okay. You can start repressurizing now, and we'd like to get you a - When you get back in configuration, we'd like a hatch integrity check for you, too. Over.
097:01:38 Stafford (onboard Snoopy): Cabin Gas...
097:01:40 Stafford (onboard Snoopy): To Auto...
097:01:45 Cernan (in Snoopy): Okay.
097:01:48 Stafford (onboard Snoopy): Cabin Gas Return to Auto.
097:01:49 Cernan (in Snoopy): Cabin Gas Return to Auto, is what you want, isn't it?
097:01:54 Duke: That's affirmative.
Setting the Cabin Gas Return valve to the Auto position, permits gas to flow into but not out of the suit circuit.
097:02:01 Cernan (in Snoopy): Okay. And we are ready to Repress, I guess, at this point.
097:02:04 Duke: Roger. Go.
097:02:06 Stafford (onboard Snoopy): Okay, [garble] get this out of the way.
097:02:16 Stafford (onboard Snoopy): Okay.
097:02:29 Stafford (onboard Snoopy): We've got 5; that's good enough, we've got 5.
097:02:38 Cernan (in Snoopy): Okay, Houston. We are up to 5.
097:02:44 Duke: Roger.
097:02:49 Stafford (onboard Snoopy): Forward Cabin Dump valve, Open in Auto; it's Auto. Press Reg B, Close.
Stafford clarifies that the LM forward hatch dump valve is now set to the Auto position allowing the valve's aneroid sensor to ensure the cabin pressure does not exceed 5.8 psia.
097:02:58 Cernan: Data procedure [garble].
097:02:59 Cernan (onboard Snoopy): We had a procedure for it. Wait a minute.
097:03:02 Cernan (in Snoopy): Do you have a procedure for us on the integrity check?
097:03:05 Duke: Say again, Snoop?
097:03:10 Cernan (in Snoopy): Okay, you're going to pass us a procedure for a hatch integrity check?
097:03:13 Duke: Negative. Just get in configuration, and if you hold pressure, that's good enough for us.
097:03:18 Stafford (onboard Snoopy): That's alright.
097:03:21 Stafford (in Snoopy): Well, we're okay.
097:03:23 Duke: Okay. Fine. You can press on. Over.
097:03:26 Stafford (onboard Snoopy): Okay.
097:03:29 Cernan (onboard Snoopy): Tom, we ought to do that regulator check, huh?
097:03:35 Stafford (onboard Snoopy): [Garble.] The tunnel's just vented down there...
097:03:43 Cernan (onboard Snoopy): Screw the damn thing. Let's go on.
097:03:45 Stafford (onboard Snoopy): Yes, let's go on. Well, I think, we - what we - our functions - I'm going to put - Let's put this final configuration for undocking, okay?
097:03:59 Duke: Snoopy/Charlie Brown, only thing is reminder Press Regs A and B back to Cabin. Over.
With the Pressure regulator valves A & B in the Cabin position, it permits regulated oxygen flow to the suit circuit to be maintained at 4.8 psia ±0.2. This is the usual position for pressurized cabin operations.
097:04:06 Stafford (in Snoopy): Roger. We'll get them, Charlie.
097:04:10 Duke: Roger.
097:04:12 Young: Okay. We're maneuvering back to the attitude this time, Tom. We're going to be a little more rigorous now.
097:04:23 Stafford (onboard Snoopy): [Garble] some flow in here; ready?
097:04:26 Cernan (onboard Snoopy): Okay. Press Reg A and B, Cabin.
097:04:28 Stafford (onboard Snoopy): Yes, they're Cabin; the Repress is Auto. All set.
097:04:38 Cernan (onboard Snoopy): [Garble] take my helmet and gloves off.
097:04:39 Stafford (onboard Snoopy): Yes.
097:04:47 Duke: Charlie Brown, Houston. Two things for you: we'd like another readout on the LM/CM Delta-P, and also disable all roll jets. Over. Until we can get undocked.
097:05:03 Young: Roger. All roll jets coming Off and LM/CSM Delta-P is 0.9.
MCC-H are requesting that all CSM roll RCS jets are disabled due to concern about slippage between the two spacecraft at the docking ring interface. They don't want any roll maneuvers which may place extra strain on this interface.
097:05:09 Duke: Roger.
097:05:13 Cernan (in Snoopy): Houston, this is Snoop. I gave the AGS an update and an alignment, and then when I checked Verb 83, my local vertical angle goes off by about 20 degrees, so I'm going through the procedure again.
097:05:26 Duke: Roger. And we have a K-factor update for you. Over.
097:05:35 Cernan (in Snoopy): Okay. Fire it.
097:05:37 Duke: Roger. 090 00 03 00.
097:05:48 Cernan (in Snoopy): 090 00 03 00?
Because of the AGS computer word size, Ground Elapsed Time cannot be used for AGS time. Instead, a time bias - K Factor (aka K Vector), is subtracted from Ground Elapsed Time and the resulting time used as AGS time. The bias used equals the Ground Elapsed Time when the AGS computer time is initialized at AGS time zero. The K Factor given to the crew equates to 90 hours 00 minutes 03 seconds exactly.
097:05:52 Duke: Affirmative.
097:06:15 Duke: Snoopy, Charlie, this is Houston. We'd like to - We got a little problem with your Gyro platform it appears, and X Gyro torquing angle is a little large. We'd like you to repeat the drift check. Over.
The concern over the excessive X Gyro torquing angle relates not to a problem with the IMU gyro's, but to a slippage in the yaw axis at the docking ring interface between the two spacecraft. MCC-H are requesting another IMU drift check to eliminate a problem with the guidance hardware.
097:06:36 Cernan (in Snoopy): Okay. You want to repeat the drift check. Roger. Give us a second, here.
097:06:40 Duke: Roger. That's on page 43.
097:06:49 Cernan (in Snoopy): Tom, when I load in the K-factor, I just load it in verb - in 90, don't I. Huh?
097:06:52 Stafford (onboard Snoopy): Yes. Yes, [garble] hot voice.
097:06:55 Cernan (onboard Snoopy): I load it in 47. They want you to do the drift check again, Tom, after this starts flashing. Yes, No problem. We haven't been doing; it that way, but [garble], we've just been going and just making the AGS monitor with that, so - yes. Six of one and half a dozen of the other. It doesn't, matter.
Using PNGS Routine 47 - AGS Initialization, the GET of the AEA clock can be set. In this routine keying Verb 25 Enter followed by GET K-factor provided by MCC-H. The K-factor is the AGS time bias, as the AGS time is limited to approximately 72 hours. AGS time = GET - K-factor time bias.
097:07:15 Duke: Charlie Brown, Houston. We'd like one more read-out of the LM/CM Delta-P. Over.
097:07:24 Young: Roger.
097:07:37 Young: Okay, it's 0.8.
CM to LM docking tunnel pressure differential has dropped to 0.8 psi.
097:07:39 Duke: Roger.
097:07:54 Cernan (onboard Snoopy): They want you to do the drift check again, Tom, after this starts flashing.
097:07:56 Stafford (onboard Snoopy): Yes, yes.
097:08:04 Duke: Snoop, Houston. We copy you entered the K-factor wrong. We need 90 hours and 3 seconds, not 30 seconds. Over.
097:08:17 Cernan (in Snoopy): Okay. 90 hours and 3 seconds. My mistake.
097:08:32 Cernan (onboard Snoopy): Better let that run its course. Why don't you start on the - on the DPS - DAP throttle tests? You can do that...
097:08:35 Stafford (onboard Snoopy): Well, I've got to get this fine aligned; then I'll...
097:08:36 Cernan (onboard Snoopy): Okay, Okay.
097:08:39 Duke: Charlie Brown and Snoop, we have 30 minutes to LOS. If we don't get the RCS hot fire in, we're still Go for undocking. You can do that on the backside. Over.
097:08:58 Stafford (in Snoopy): Roger. What's the latest time for undocking now, Charlie?
097:09:02 Duke: Stand by.
097:09:24 Cernan (in Snoopy): Tom, you go ahead and get that drift.
097:09:30 Young (onboard): [Garble] be flashing a [garble] and I'll need that to [garble]...
097:09:36 Duke: Snoop, Houston. Undocking time is 98 22. You got an hour and 4 minutes. Over.
097:09:49 Stafford (in Snoopy): Roger. 98 22 00.
097:09:56 Stafford (onboard Snoopy): This thing's operating so slow, I can't...
097:10:00 Young (onboard): Yes, I know, it really is. Okay.
097:10:07 Stafford (in Snoopy): Charlie Brown, Snoop. We're ready to do another one of those drift checks. Let me know when you have Verb 06, Noun 20, and I'll give you a Mark when they Enter. Over.
Keying Verb 06 Noun 20 will display the CM ICDU angles.
097:10:16 Young: Over.
097:10:18 Stafford (in Snoopy): Roger. 3, 2, 1.
097:10:21 Stafford (in Snoopy): Mark.
097:10:22 Stafford (onboard Snoopy): Verb 06, Noun 20.
097:10:23 Young: Okay. Plus 00393, plus 01300, plus 0428.
097:10:36 Stafford (in Snoopy): Roger. Copy. That's 00393, 01300, and 0428. We need one more number.
097:10:47 Young: 00428.
Once again the crew are repeating the transfer of the ICDU angles (see detailed explanation at 095:00:03).
097:10:50 Stafford (in Snoopy): Okay. Got it.
097:11:00 Stafford (onboard Snoopy): Which one?
097:11:08 Stafford (onboard Snoopy): Okay.
097:11:08 Duke: Snoop, Houston. Let me read you the angles that we got...
097:11:10 Stafford (in Snoopy): What say?
097:11:11 Duke: ...and see if they confirm. You ready to copy?
097:11:16 Stafford (in Snoopy): Go.
097:11:17 Duke: Roger. For the CSM, it's plus 00393, plus 01300, plus 00428. For the LM, plus 29959, plus 19285, plus 35578. Over.
Capcom Charlie Duke is confirming the ICDU angles for the CSM and the converted angles for the LM.
097:11:39 Stafford (onboard Snoopy): Houston, Snoopy. Those are correct. Over.
097:12:03 Duke: Snoop, Houston. Somebody cut in on us here on the loop. Did you copy those angles?
097:12:11 Stafford (in Snoopy): Roger. I copied them and they look correct. We're going to go ahead and go through the DAP throttle set here.
097:12:17 Duke: Rog.
Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
097:12:20 Cernan (in Snoopy): Hey, Tom, circuit breaker Stab Control DECA Power closed? Mode Control, Auto.
The DECA (Descent Engine Control Assembly) PWR circuit breaker on the Stab/Cont panel 11 on the CDR's side of the LM cabin is closed to provide power to control the descent engine throttle and gimbals.
DECA Power circuit breaker - Panel 11.
097:12:23 Stafford (onboard Snoopy): Go.
097:12:25 Cernan (onboard Snoopy): Mode Control, Auto:
The Mode Control switches on panel 3, when set to Auto for PGNS & AGS, will command the RCS to maintain the spacecraft attitude.
Mode Control switches - Panel 3.
097:12:27 Young: Okay, Houston. Charlie Brown here.
097:12:29 Duke: Go ahead.
097:12:34 Cernan (in Snoopy): Verify Guidance Control, PGNCS.
Guidance Control switch on panel 1 selects whether the PGNS or AGS provide the guidance control commands.
Guidance Control switch - Panel 1.
097:12:36 Young: Roger. What about not rolling to this 180 degree roll, here, until we get undocked. Would that be all right?
097:12:43 Duke: Stand by.
097:12:44 Cernan (onboard Snoopy): Throttle Control, Manual. Manual Throttle, Commander. TTCA, Commander; Throttle, and Min. Way down, now. Remember that.
With the Throttle Control switch on panel 1 in the Manual position, the LGC throttle commands are interrupted to ensure that the descent engine only receives manual throttle inputs.
The Manual Throttle switch also on panel 1, dictates which crewman's thrust/translation controller assembly (TTCA) is enabled to adjust the descent engine thrust level. In this case it is set to Commander.
Throttle Control and Manual Throttle switches - Panel 1.
The TTCA Throttle/Jets select lever, on the commanders side of the LM cabin, is set to Throttle to enable him to adjust the descent engine thrust level and hence translation in the Y-axis. The reference to Min, relates to the friction control knob on the TTCA which adjusts the amount of force required to move the control T-handle, upwards or downwards.
Thrust/translation controller assembly (TTCA).
097:12:55 Stafford (onboard Snoopy): Yes, got it.
097:13:02 Young: I don't know how I'm going to roll with the roll jets disabled.
097:13:05 Duke: Rog. We copy, John. Stand by. We're running this one around the room, and I've got a Sep PAD if you're not busy.
097:13:14 Stafford (onboard Snoopy): Proceed [garble].
097:13:21 Young: Go to it. Over.
097:13:22 Duke: Roger. Sep. It's RCS/G&N and it's NA down to Noun 33, and we've got 098:47:16.00, NA down to the pitch angle, 014 degrees. Over.
097:13:47 Stafford (onboard Snoopy): Proceed.
097:13:50 Young: Roger. 098:47:16.00. 14 degrees pitch.
097:13:52 Stafford (onboard Snoopy): What's our trim?
097:13:57 Duke: Good readback, Charlie Brown.
The CSM SEP PAD consists of:
097:14:05 Stafford (in Snoopy): And we go Engine Arm. Descent, and we do not Proceed. Okay, we did Verb 34, Enter.
The Engine Arm switch on panel 1 is set to Descent which provides the arming signal to enable firing of the descent engine and signals the LGC that the descent engine is armed. This is to facilitate an upcoming test of the descent engine throttle command using the TTCA.
Engine Arm switch - Panel 1.
As part of the DAP Data Load using LGC routine 03 being performed by Stafford, Verb 34 is used to terminate this routine without enabling the descent engine gimbal to the trim position.
097:14:24 Stafford (in Snoopy): Okay. Houston, this is Snoopy. TTCA coming up to 40 percent.
097:14:35 Duke: Roger.
097:14:36 Stafford (in Snoopy): Now soft stop. Now Max throttle. Now Min...
097:14:43 Duke: Rog. We copy.
097:14:44 Stafford (in Snoopy): ...and it looks good.
Stafford tests the TTCA descent engine manual throttle control.
097:14:46 Duke: Roger. We copy.
097:14:47 Duke: And Charlie Brown, we noticed when you went through your DAP load, you did not update your gimbal trims, and they're quite a bit off. Over.
097:15:03 Young: Okay. I'll fix them.
097:15:06 Cernan (in Snoopy): Houston, Snoopy. How's that for a K-factor time?
097:15:13 Duke: Stand by.
097:15:19 Cernan (in Snoopy): Okay. If it's a good K-factor time, it's going in.
097:15:27 Duke: Okay. The K-factor's good.
MCC-H confirms that the AGS time bias entered, the K-factor is correct.
097:15:33 Cernan (in Snoopy): Okay. Tom, you got Engine Arm Off?
097:15:35 Stafford (onboard Snoopy): Yes.
097:15:36 Cernan (in Snoopy): Breaker Stab Control DECA Power Open?
With the Engine Arm switch returned to the Off position, the arming signal is disabled for the descent engine valves and the LGC.
The Stab Cont DECA Pwr circuit breaker on panel 16 is opened to remove DC power from the DECA which controls the descent engine throttle and gimbals.
097:15:37 Stafford (onboard Snoopy): Yes.
097:15:38 Cernan (in Snoopy): Throttle Control, Auto.
The Throttle Control switch on panel 1 is returned to the Auto position now that the manual throttle test is complete. In the Auto position, throttle commands for the descent engine from the LGC are combined with the TTCA throttle level.
097:15:39 Stafford (onboard Snoopy): Yes.
097:15:40 Cernan (in Snoopy): TTCA, Jets.
The TTCA select lever is moved to the JETS position to allow this control to provide manual translation commands to the RCS.
097:15:41 Stafford (onboard Snoopy): Go.
097:15:42 Cernan (onboard Snoopy): Mode Control: PGNS, Off.
With the PGNS Mode Control switch on panel 3 set to the OFF position, translation commands from the LGC or TTCA are disabled. Whilst still docked the CSM will provide all translation inputs for the combined spacecraft. At this point in the timeline the RCS have not yet been pressurized and tested.
097:15:44 Stafford (onboard Snoopy): Yes.
097:15:44 Duke: Charlie Brown, Houston. If you can give us a P00 and Accept, we've got the load for you.
097:15:52 Cernan (in Snoopy): I'm down to page 47. I did everything up here, Tom.
097:15:56 Stafford (onboard Snoopy): Yes.
097:15:57 Young: You have it.
097:15:58 Duke: Rog.
097:16:05 Cernan (in Snoopy): Yeah, I got all the RCS pressure verification.
097:16:13 Stafford (onboard Snoopy): Are we, are we still on hot mike?
097:16:15 Cernan (onboard Snoopy): No.
097:16:18 Stafford (onboard Snoopy): Okay, let's go through it.
097:16:19 Cernan (onboard Snoopy): Okay, Master Arm, On. Do you have it on? Right here.
097:16:24 Stafford (onboard Snoopy): Okay, Master Arm, On. Got the Stage Sequence light.
097:16:28 Cernan (in Snoopy): Okay Master Arm's On, helium pressure RCS, Fire. And I'll [garble]. Stand by, baby.
The crew have now moved on to the RCS pressurization. The Master Arm switch on panel 8 enables actuation of all LM explosive devices by actuating redundant relays that route power to the EDS (Explosive Devices Subsystem) buses.
Master Arm, RCS He Press switches and Stage Seq Relay - Panel 8.
The LM RCS propellants are pressurized with gaseous helium at a nominal pressure of 3,050 psia. The helium flows from its storage tank in the ascent stage through two parallel paths. With the Master Arm switch ON and the RCS-He PRESS switch set to FIRE, the explosive valve in each of these paths is opened. Because of the redundant paths, should one of the explosive valves fail to open, RCS pressurization will still occur. Pressure regulators reduce the RCS propellant tank pressure to approximately 181 psia.
The Stage Sequence Relays Sys A & B caution light on panel 8 comes on to indicate the EDS buses A and B are armed.
097:16:37 Stafford (onboard Snoopy): Ready?
097:16:38 Cernan (in Snoopy): Oh, wowie! Okay. There's helium pressure kickdown slightly. Where did it go? Hey, we're Go on that pressurization.
097:16:50 Stafford (onboard Snoopy): Turn it Off, Master Arm, Off.
With the RCS now pressurized the Master Arm switch on panel 8 is now placed in the Off position safing all LM explosive devices.
097:16:53 Cernan (in Snoopy): Okay. Recycle. Let me recycle these valves. See what happens, those damn things go when you do it.
097:17:03 Stafford (onboard Snoopy): Okay. It looks like we got all the Parker valves squared away.
Parker Hannifin manufactured the fuel and oxidizer valves that were a component of the RCS propellant system. They had a habit of fully shutting off, so to ensure their proper operation they were cycled on and off using the RCS Quad TCA circuit breakers on panels 11 and 16, 4 valves on each panel serving the two RCS propellant loops. The TCA breakers provide 28V DC power to the primary coils in the RCA Thrust Chamber Assemblies to control the propellant valves.
RCS Quad TCA circuit breakers - Panel 11.
RCS Quad TCA circuit breakers - Panel 16.
097:17:13 Young: Hey, Snoop. You know you're transmitting.
097:17:15 Cernan (in Snoopy): Yeah, I know it. Okay. Verify Master Alarm, Off.
097:17:17 Stafford (onboard Snoopy): Go.
097:17:18 Cernan (in Snoopy): And RCS Regs A and B warning lights are Off.
The RCS A and B Reg warning annunciator lights on panel 1 come on when pressure sensed by pressure transducer downstream of RCS system A and B pressure regulators exceeds 218 psia or drops below 165 psia.
RCS REG system A and B warning annunciator lights - Panel 1.
097:17:20 Stafford (onboard Snoopy): Go. Descent Reg.
097:17:38 Cernan (in Snoopy): Okay. I verify the pressures and temperatures in the RCS, and they're all Go. And, Houston, this is Snoopy. Our helium pressure on both RCS rings is 2,900 psi.
097:17:52 Duke: Roger.
Cernan (onboard Snoopy): T.P, let me start out with the - Okay, Stab/Control: Attitude Direct Control, Closed on your side. Guidance Control PGNS, that's go. Deadband, Max.
The helium tank pressure is temperature dependent. At 21°C (70°F) the nominal pressure is 3,050 psia. The readout Cernan is giving is measured at each the pressure regulator in each of the redundant pressurization loops. The reading is very close to nominal.
CSM/LM relative attitude references.
The Stab/Cont ATCA circuit breaker on panel 11, when closed, applies DC power through the Guidance Control-PGNS switch. It also applies DC power through the PGNS Mode Control switch to the ATCA (Attitude and Translation Control Assembly) primary preamplifiers to be used by the PGNS for attitude control.
Stab/Cont ATCA circuit breaker - Panel 11.
The Deadband switch on panel 3 set to Max, provides a large amplitude limit for attitude control when preserving RCS propellant during coasting flight. The deadband limits the degree of attitude drift either side of the ideal before the spacecraft's control system actively corrects the drift using the LM RCS. Maximum attitude deadband is ±5°. This switch is not functional when PGNS is in use. In the Min position, the deadband is limited to ±0.3° in roll and ±0.4° in yaw. When in Min the rate of attitude change is limited to 5°/sec in roll and 10°/sec in yaw.
097:18:20 Cernan (in Snoopy): X-Translation. 4 jets.
The Att/Transl switch on panel 1 selects the number of RCS jets to be used for X translation manoeuvres. This control can only be used when in AGS.
Att/Transl switch - Panel 1.
097:18:22 Stafford (onboard Snoopy): Go.
097:18:24 Cernan (in Snoopy): Mode Control PGNS, Attitude Hold.
With the PNGS Mode Control switch on panel 3 in the Att Hold position, the crew can manually command angular rates using the RCS via inputs using the ACA (Attitude Control Assembly). This mode will function under both PGNS and AGS control.
097:18:26 Stafford (onboard Snoopy): Go.
097:18:27 Cernan (in Snoopy): Attitude Control, three, Pulse.
With the three (roll, pitch and yaw) Attitude Control switches on panel 3 in the Pulse position, two RCS jets in the selected axis fire at a constant pulsed rate as long as the ACA is displaced by more than a quarter of its full displacement. The attitude rates induced must be nulled to zero by inputting the opposite command manually.
Three Attitude Control switches - Panel 3.
097:18:32 Stafford (onboard Snoopy): Go.
097:18:33 Cernan (in Snoopy): ACA, Four Jets (Commander), Disable. TTCA is Enabled.
With the ACA/4 Jet switch on the commanders side of panel 4 in the Disable position, the 4 jet attitude control function of the commanders ACA is disabled. Placing the TTCA/Transl switch on the commanders side of panel 4 in the Enable position, enables normal operation of the commanders TTCA (translation and throttle control assembly).
ACA/4 Jet and TTCA/Transl switches on the commander's side of panel 4.
097:18:40 Stafford (onboard Snoopy): Go.
097:18:51 Cernan (in Snoopy): Okay, Charlie Brown. This is Snoopy. We're calling for you to be in a Min Deadband, Attitude Hold. Okay.
During this part of the LM RCS checkout, the CSM needs to be configured with the Att Deadband switch on panel 1 placed in the Min position, which switches the electrical deadband out of the Electronic Control Assembly (ECA) attitude control loop in all 3 axes. The ECA performs the function of summing the data from each group of three BMAGs (Body Mounted Attitude Gyro). Removing the electrical deadband provided by the ECA, the attitude deadband is reduced by ±4° to ±0.2°.
Attitude Hold uses the control signals provided by the rate and attitude BMAGs and is selected by placing the BMAG Mode switches on panel 1 for Roll, Pitch and Yaw in the Att 1 Rate 2 position. In this position, BMAG group 1 provides the attitude reference and BMAG group 2 the rate reference. This is to ensure the CSM does not try to compensate for the LM RCS test firings.
Att Deadband and BMAG Mode switches - Panel 1.
097:19:05 Young: Roger. Give me a second.
097:19:29 Young: Okay. Min and hold. You got it.
097:19:34 Cernan (in Snoopy): Okay. We are going to start your RCS checks, and we'll give you a hack when we go hot fire.
097:19:37 Young: Okay. Remember I don't have any roll jets.
097:19:40 Stafford (in Snoopy): Roger. And we will not yaw.
MCC-H has instructed CMP, John Young not to fire the CSM roll RCS jets due to concerns over the apparent docking ring slippage. Young is reminding his colleagues in the LM of this limitation. CDR, Stafford reply assures Young that the LM will not manoeuvre in yaw. Yaw attitude changes in the LM are the same as roll changes in the CSM whilst in the docked configuration.
LM axes.
097:19:43 Duke: And, Charlie Brown, you can have your computer back. We're through with your load, and we're with you, Snoop, on the hot fire.
097:19:51 Stafford (in Snoopy): Okay. Charlie.
097:20:02 Cernan (in Snoopy): Okay. These are all cold fire. Cross stop, roll right.
During the RCS cold fire tests, both ACAs and TTCAs are used to check electrical connections from each controller to the RCS jet drivers in the ATCA (Attitude and Translation Control Assembly).
097:20:10 Stafford (onboard Snoopy): God damn!
097:20:12 Cernan (onboard Snoopy): Let me recycle those.
097:20:18 Stafford (onboard Snoopy): Damn caution and warning system.
097:20:19 Cernan (in Snoopy): Okay. Try rolling right again.
097:20:24 Stafford (onboard Snoopy): There's another one. Freak.
Another Caution and Warning alarm.
097:20:28 Cernan (in Snoopy): That's no good. Roll left.
097:20:36 Cernan (in Snoopy): Houston, are you reading these numbers?
097:20:37 Duke: Roger. We're reading them.
097:20:42 Cernan (in Snoopy): Okay pitch up. Okay. Pitch down. Okay. Yaw right. This is cold fire.
097:21:04 Cernan (in Snoopy): Okay. Yaw left.
097:21:13 Cernan (in Snoopy): Okay. John you can go to wide deadband Attitude Hold. Houston, what do you make out of that?
Whilst remaining in Attitude Hold, leaving the BMAG Mode switches in the Att 1 Rate 2 position, the Att Deadband switch is moved to the Max position. In this position the electrical deadband from the Electronic Control Assembly (ECA) attitude control loop in all three axes is switched back in. This sets the attitude deadband to ±4.2°. This is in preparation for the LM RCS hotfire tests to ensure the CSM does not try to counteract the LM induced attitude excursions.
097:21:18 Stafford (onboard Snoopy): I want to make - I want to - [garble].
097:21:20 Young: Roger.
097:21:21 Duke: Stand by. I think we're okay. Stand by.
097:21:54 Stafford (onboard Snoopy): You want to put your helmet and gloves on for this?
097:22:15 Cernan (Snoopy): Houston, we'll stand by for your Go until we proceed further.
097:22:19 Duke: Roger. Stand by. And, Charlie Brown, we show you in the DAP MIN deadband, over.
097:22:30 Young: That's right.
097:22:37 Cernan (in Snoopy): Charlie Brown, you can go to wide deadband for us now, attitude hold.
Repeated request for the CSM to go to Att Deadband Max, Attitude Hold.
097:23:02 Young: [Garble] undocking [garble].
097:23:04 Cernan (in Snoopy): [Garble] We haven't begun the day yet.
097:23:05 Stafford (onboard Snoopy): Yes (laughter). You want to be on hot mike?
097:23:13 Cernan (onboard Snoopy): Make any difference?
097:23:36 Stafford (onboard Snoopy): Look at those.
097:23:38 Cernan (onboard Snoopy): They'll go out when you can push the valves, push the breakers in.
097:23:48 Stafford (onboard Snoopy): We can't wait around for them to...
097:23:49 Cernan (onboard Snoopy): Let's - let's continue.
097:23:50 Duke: Snoop, we're Go with those numbers in the cold fire. Go ahead with the Min (minimum) impulse, step 5.
097:23:58 Stafford (in Snoopy): Okay. Real good. We'll go ahead. That's the first time we've seen numbers that haven't gone to the full range. I just wanted to check with them, the whole analysis [garble] Okay. We'll go ahead.
097:24:07 Cernan (in Snoopy): Guidance Control, AGS. AGS, Attitude Hold.
The crew are selecting AGS as the method of Guidance Control. The AGS Mode Control switch on panel 3 is going to Att Hold. In this mode whilst under AGS control, the crew can command angular rates proportional to the displacement of ACAs.
097:24:12 Stafford (onboard Snoopy): Go.
097:24:15 Cernan (in Snoopy): Okay. Attitude Control, three, Mode Control. Okay. Your Commander is four jet, Enable. Now, when you hit hard over here, it's going to be a hot fire.
With the three (roll, pitch and yaw) Attitude Control switches on panel 3 in the Mode Control position, this enables the ACA proportional attitude rate mode.
With the ACA/4 Jet switch on the commander's side of panel 4 in the Enable position, the 4-jet attitude control function of the commander's ACA is enabled. The commander can control the vehicle attitude in all axis by moving the ACA to the hardover position.
097:24:23 Stafford (onboard Snoopy): Yes.
097:24:26 Duke: Charlie Brown, Houston. We'd like you in wide deadband. Over.
Duke is reminding Young to switch to Max Att Deadband during the LM RCS hot fire tests.
097:24:30 Young (onboard): Stand by.
097:24:47 Cernan (in Snoopy): Charlie Brown, let us know when you get in wide (deadband) because some of these are going to be hot fire.
097:24:59 Young: Okay. We're in wide.
097:25:01 Stafford (onboard Snoopy): Okay.
097:25:02 Cernan (in Snoopy): Okay. We're going to proceed, and we'll let you know when we hot fire here.
097:25:03 Stafford (onboard Snoopy): Okay.
097:25:06 Cernan (in Snoopy): Okay, Tom we don't want any yaw. Is that right?
097:25:10 Stafford (in Snoopy): That's right.
Cernan is reminding Stafford to avoid any yaw excursions due to the apparent slippage of the docking ring between the two vehicles.
097:25:11 Cernan (in Snoopy): Okay, roll right and, John, you'll get a pulse of hot fire. Let's go. Pulse it.
097:25:17 Young (onboard): Good.
097:25:21 Cernan (in Snoopy): Left. roll, pitch up, roll, pitch down.
097:25:30 Stafford (in Snoopy): Okay, thrusters seemed nice and crisp. Seemed real good.
097:25:33 Young: Okay. You want to yaw right and left without going to the hard stops?
097:25:40 Stafford (in Snoopy): Yes.
097:25:41 Cernan (in Snoopy): Let's go. Okay. Attitude Control, three, Pulse. Okay get your four GTA (should read TCA-Thrust Chamber Assembly) breakers in and I'll get mine in.
Taking up Young's suggestion to check the RCS in the yaw axis with only small inputs, the Attitude Control switches for each of the three axis are placed in the Pulse position.
Closing the four RCS TCA breakers on both panels 11 and 16 provides 28V DC power to the TCA primary coils to allow automatic RCS control.
097:25:53 Young (onboard): You want me to recycle the [garble] here?
097:25:55 Cernan (in Snoopy): All in?
097:25:56 Stafford (onboard Snoopy): Yes.
097:26:06 Cernan (in Snoopy): Okay. CWEA open and closed. Okay. All the lights are off. All the flags are off. This is the hot fire in the AGS. Commanders - TTCA; okay, ready to do it?
The CWEA (Caution and Warning Electronics Assembly) circuit breaker on panel 16 is cycled off (open) and on (closed) as part of the CWEA test.
CWEA circuit breaker - LM panel 16.
097:26:25 Stafford (onboard Snoopy): Yes.
097:26:30 Cernan (in Snoopy): Up, down, right, left, and then fore and aft. John, are you ready for a hot fire?
097:26:37 Young: Go ahead.
097:26:38 Cernan (in Snoopy): Okay. Up, down, right, left.
097:26:42 Stafford (onboard Snoopy): Go.
097:26:40 Cernan (in Snoopy): Forward, aft. I guess they all fired, babe.
097:26:54 Stafford (in Snoopy): They all fired, Houston, but we couldn't get it on the DSKY, because I made a real short pulse.
097:26:58 Cernan (in Snoopy): You wouldn't get them anyway. This is AGS, babe. We weren't...
097:26:59 Stafford (in Snoopy): Yes. Right. Yes.
097:27:01 Duke: Roger, Snoop. We copy. Charlie Brown, we'd like to go BMAGs Att 1 Rate 2, so we can get some attitude hold. Over.
Duke is giving Young a gentle reminder of the BMAG Mode switch setting required to go into attitude hold.
Download MP3 audio file. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.
097:27:13 Stafford (onboard Snoopy): Okay.
097:27:15 Cernan (onboard Snoopy): Guidance Control, PGNS.
Guidance Control switch on panel 1 is returned to the PGNS position. This will enable the PGNS to control the remaining RCS hot fire tests.
097:27:17 Stafford (onboard Snoopy): Yes.
097:27:18 Cernan (onboard Snoopy): Okay, now we'll see them on here. You better tell them we're going to hot fire again.
097:27:30 Cernan (in Snoopy): John, we're going to hot fire again. You ready?
097:27:34 Young: Go ahead.
097:27:35 Cernan (onboard Snoopy): Okay. Go up.
097:27:37 Stafford (onboard Snoopy): It fired.
097:27:41 Cernan (onboard Snoopy): Down , You got to fire long, and I don't think we want to.
097:27:46 Stafford (onboard Snoopy): No.
097:27:47 Cernan (onboard Snoopy): Right.
097:27:48 Stafford (onboard Snoopy): Yes.
097:27:49 Cernan (onboard Snoopy): Left, forward, aft.
097:27:54 Stafford (onboard Snoopy): Did we get a - We got to hit it E, 6, Enter [garble].
097:27:58 Cernan (onboard Snoopy): Son of a bitch, yes, I do. We never got a - Hit a E 6 E. Enter 6. Okay, now try the right and let, fore and aft again. Okay, we got this and we got this, but you've got to hold them longer, and - we don't want to hold them longer.
097:28:28 Stafford (onboard Snoopy): Yes, I don't want to waste any...
097:28:29 Cernan (onboard Snoopy): Why don't you tell them that?
097:28:31 Stafford (in Snoopy): Okay, Houston. You probably read the DSKY didn't go, but I didn't - I made just short pulses. I didn't want to waste any fuel here and hold it that long with the condition we have in the tunnel. So, they fired and they fired real crisp, so I think we're in good shape. Okay.
097:28:44 Cernan (onboard Snoopy): X-Translation, 2 Jets.
Att/Translation switch on panel 1 is placed in the 2 Jets position. This control is only active when under AGS control.
097:28:45 Duke: Roger. We copy, Snoop. Stand by for our Go.
097:28:51 Stafford (onboard Snoopy): Want to go AGS?
097:28:53 Cernan (onboard Snoopy): Guidance Control, AGS.
Guidance Control is returned to AGS via the switch on panel 1.
097:28:54 Stafford (onboard Snoopy): Go.
097:28:57 Cernan (onboard Snoopy): Okay, We go right into rendezvous radar self-test.
097:29:06 Stafford (in Snoopy): Okay, Charlie Brown, Snoop. Verify that RCS thruster B3 Off, and your Radar Transponder Off.
097:29:13 Young: Roger. The Radar Transponder; Heater and B3's Off.
Service Module RCS thruster B3 points in the direction of the rendezvous radar on the LM. As the LM Rendezvous Radar is about to be released from its stowed position, leaving it open to gaseous impingement if this thruster was used.
SM RCS thruster B3 and the LM Rendezvous Radar - Image by John Ortmann.
The Rendezvous Radar Transponder switch on panel 100 is placed in the Heater position to prepare it for use following undocking. The tone filters need to be heated between 16°C and 70°C (60°F and 160°F). This warm up requires a minimum of 24 minutes.
Rendezvous Radar Transponder switch - Panel 100.
097:29:18 Stafford (in Snoopy): Roger.
Stafford (onboard Snoopy): Okay. Rendezvous Radar. Release.
The Rendezvous Radar release cable is activated by a handle that is mounted on the left side of the frame that surrounds the AOT. The Rendezvous Radar is securely retained until it is activity required. This is mainly to protect the antenna during launch, the LM ejection from the S-IVB third stage and during LOI.
Rendezvous Radar release handle.
Rendezvous Radar release lanyard assembly.
Rendezvous Radar release lanyard assembly.
097:29:20 Duke: And, Snoop/Charlie Brown. You're Go for undocking. We had one indication that the - On your hot fire that jet B3 down, we had a TCP stuck on, but if you don't hear anything, we're Go.
Duke's reference to TCP relates to the RCS Thrust Chamber Pressure (TCP) switch. The RCS TCA C&W light on panel 1 will light up if a command is issued to primary coil on a specific thruster but no chamber pressure is measured by the TCP in that thruster. With the TCP switch on thruster B3 stuck on, this failure light would not come on if the thruster did not fire on command.
RCS TCA Caution and Warning light - LM panel 1.
097:29:40 Stafford (in Snoopy): Sounds good here.
097:29:41 Duke: Okay.
097:29:42 Cernan (onboard Snoopy): Crosspointers, both, Hi Multiply.
Each crew member in the LM has a Crosspointer indicator, CDR on panel 1, LMP on panel 3. Each indicator has a switch nearby that sets scale range displayed. In the Hi Multiply position, when Line of Sight (LOS) azimuth and elevation rates are displayed, this position provides a scale of ±20 mrad/sec. When horizontal velocities are displayed, this position illuminates the X10 multiplier to provide range of ±200 fps.
X-Pointer indicator and mode switch - LM panel 1 (repeated on panel 3).
097:29:43 Stafford (onboard Snoopy): Go.
097:29:46 Cernan (in Snoopy): We're proceeding with the rendezvous radar self-test. Rate/Err Monitor, both, Rendezvous Radar.
A group of switches associated with the Rendezvous Radar displays on panel 1 and some are also available on the LMP side of the cabin, are now configured. The Rate/Error Monitor switches also on both panels 1 & 2, selects the input for the FDAI and X-Pointer indicators. When placed in the Rendezvous Radar position the shaft and trunnion angles from the RR are displayed by pitch and yaw error needles of FDAI; Line of Sight (LOS) azimuth and elevation rates are displayed on X-Pointer indicator (illuminating LOS AZ and LOS Elev).
097:29:50 Stafford (onboard Snoopy): Yes.
097:29:52 Cernan (onboard Snoopy): Attitude Monitor, both, PGNS.
The Attitude Monitor switch on panel 1 and panel 2 selects the input for the FDAI total attitude display. In the PGNS position, LM total attitude signals, after conditioning by GASTA (Gimbal Angle Sequencing Transformation Assembly) are fed to FDAI ball; LGC attitude error signals are fed to FDAI pitch, roll, and yaw error needles.
097:29:54 Stafford (onboard Snoopy): Go.
097:29:56 Cernan (onboard Snoopy): Mode Select, Landing Radar.
097:29:59 Stafford (onboard Snoopy): Rendezvous Radar, isn't it?
097:30:00 Cernan (onboard Snoopy): Landing Radar.
097:30:01 Stafford (onboard Snoopy): Landing Radar, right. Go.
The Mode Select switch on panel 1 selects radar or computer data for display on X-Pointer and altitude/range indicators. In the LDG RDR/CMPTR position radar altitude, altitude rate, and forward and lateral velocity are displayed on the X-Pointer indicator and altitude/range indicators.
097:30:03 Cernan (onboard Snoopy): [Garble] Range Rate - Range Rate Monitor, Range Rate.
The RNG/ALT Mon switch on panel 1 when set to the RNG/RNG RT position, selects display legend on altitude/range indicator and displays rendezvous radar range/range rate data or LR or computer altitude/altitude rate data.
097:30:07 Stafford (onboard Snoopy): Yes.
097:30:08 Cernan (onboard Snoopy): Shaft/Trunnion, ±50°.
Shft/Trun angle switch on panel 1 selects range of RR shaft and trunnion angles to be displayed by FDAI pitch and yaw error needles when either RATE/ERR Mon switch is set to RNDZ Radar. In the ±50° position, full deflection of FDAI pitch and yaw error needles indicates shaft and trunnion angles of +50° or -50° or greater. Less than full deflections are proportional +50° or -50°.
Rate/Error Monitor, Attitude Monitor, Mode Select, Range/Altitude Monitor and Shaft/Trunnion switches - LM panel 1.
097:30:12 Stafford (onboard Snoopy): Yes.
097:30:13 Cernan (onboard Snoopy): Rendezvous Radar. Slew.
097:30:16 Stafford (onboard Snoopy): Go.
097:30:17 Cernan (onboard Snoopy): Put it to Slew position, Okay?
The Rendezvous Radar mode selector switch in the Slew position allows manual control of the rendezvous radar antenna drive using the Slew switch.
Rendezvous Radar mode selector switch and Temp Monitor mode selector switch - LM panel 3.
097:30:19 Stafford (onboard Snoopy): I am.
097:30:20 Cernan (onboard Snoopy): Temperature Monitor, Rendezvous Radar, plus, 10 to 145.
The Temperature Monitor mode selector switch on panel 3 in the Rndz Radar position selects the temperature of the rendezvous radar drive motor to be monitored using the gauge immediately above the switch.
097:30:22 Stafford (onboard Snoopy): Go.
097:30:24 Cernan (onboard Snoopy): Circuit breaker AC Bus A - Rendezvous Radar. Close.
Closing the AC Bus A - Rndz Rdr circuit breaker on panel 11, provides AC power to the radar.
AC Bus A, Rndz Rdr and PGNS Rndz Rdr circuit breakers - LM panel 11.
097:30:27 Stafford (onboard Snoopy): Go.
097:30:28 Cernan (onboard Snoopy): And Range/Range Rate. Altitude/Altitude Rate.
The Rng/Alt Mon switch on panel 1 when set to the Alt/Alt RT position, selects display legend on altitude/range indicator and displays rendezvous radar range/range rate data or LR or computer altitude/altitude rate data from the source selected on the Mode Sel switch.
097:30:30 Stafford (onboard Snoopy): Go.
097:30:32 Cernan (onboard Snoopy): Now wait 30 seconds.
097:30:32 Duke: Snoopy, Houston. Got some word for you on your torquing angles, your platform. Over. If you can listen.
097:30:39 Stafford (onboard Snoopy): Standby.
097:30:42 Cernan (in Snoopy): Go ahead. We're listening.
097:30:44 Duke: Roger, Gene-o. It looks like we got a constant bias in the, in yaw in your platform. On our two drift checks, we get a bias of - a torquing angle of minus 03.540, and it appears to be a constant bias because it's been the same between the two different drift cheeks. We're Go with that constant bias. We'd like Charlie Brown to look through the - his rendezvous window and see if we have a constant slippage, maybe, in the - in our docking attitude, and you can tell that by looking at the docking target. Over.
MCC-H are still looking to confirm the apparent yaw bias (when compared to the CSM attitude) on the LM guidance platform is as a result of slippage at the docking interface between the two spacecraft. They have asked the CMP to confirm visually if he can detect the misalignment of the two vehicles when observing the LM docking target through the left hand rendezvous window (see diagram below).
Docking Aids.
097:31:26 Young: Roger. Charlie.
097:31:30 Cernan (in Snoopy): And, Charlie, give me a hack when we get close to LOS so that I can get off the high gain, will you?
097:31:34 Duke: Okay. We got 8 minutes.
097:31:43 Young: Okay. I'll stay with you, if you pick me up at about 2 or 3 minutes. I'll go off.
097:31:48 Stafford (onboard Snoopy): Okay.
097:31:50 Cernan (onboard Snoopy): Okay. PGNS Rendezvous Radar circuit breaker, Closed.
Closing the PGNS Rndz Rdr circuit breaker on panel 11, provides DC power to the radar and acts as an on-off switch for the Rendezvous Radar electronics assembly.
097:31:52 Young: You just yawed off. You yaw to my left about I'd say 2 degrees or so.
Young can now visually detect that the LM is yawing slightly due to the slippage at the docking interface.
097:32:04 Stafford (onboard Snoopy): Okay. Go.
097:32:05 Duke: Okay. Fine. We get a 3-degree bias, so that's it. Be advised that you're drifting off in yaw, Charlie Brown. You might want to watch your attitude.
097:32:16 Young: Roger.
097:32:17 Stafford (onboard Snoopy): Okay. Go.
097:32:18 Cernan (onboard Snoopy): Okay. Flight Displays: Range/Range Rate, Altitude/Altitude Rate. Closed.
097:32:23 Stafford (onboard Snoopy): Okay.
097:32:26 Cernan (onboard Snoopy): Range Rate...
097:32:27 Stafford (onboard Snoopy): I got it.
097:32:30 Cernan (onboard Snoopy): ...and Altitude/Altitude Rate.
Closing the Flight Displays Rng/Rng RT, Alt/Alt RT circuit breaker on panel 11 provides DC power to the Range/Range Rate or Alt/Alt Rate indicator on panel 1.
Range/Range Rate and Alt/Alt Rate indicator - LM panel 1.
097:32:34 Stafford (onboard Snoopy): Okay. Should be coming out of mode 2.
The three rendezvous radar modes are:
  1. Automatic tracking.
  2. Slew.
  3. LGC control.]
097:32:48 Stafford (onboard Snoopy): Go ahead.
097:32:56 Cernan (onboard Snoopy): Slew up, down, left, and right. Then go to Low mode and Shaft/Trunnion, ±5°, and do the same thing.
The Rendezvous Radar Slew switch on panel 3 slews the shaft or trunnion servos, or both in combination, to position the radar antenna for manual acquisition of the target, which once acquired can be tracked automatically. There are two slew rates, Hi and Low. The switch has four positions; up, down, left and right. Acquisition of the target can be determined using the Signal Strength meter, also on panel 3. It is possible to determine the rendezvous radar alignment by reading off the FDAI pitch and yaw error needles when the Rate/Err Mon switch on panel 1 is in the Rndz Radar position. The Shaft/Trunnion angle switch, also on panel 1, selects the scale range of the FDAI pitch and yaw error needles.
097:33:11 Stafford (onboard Snoopy): Looks good. Go.
097:33:13 Cernan (onboard Snoopy): Rendezvous Radar, Auto Track; caution light, master alarm, Radar Test, Rendezvous Radar; range tape drives and cross-pointers.
With the Rendezvous Radar mode selector in the Auto Track position on panel 3, the radar maintains track of the target by comparing the received radar signals from three separate channels. The resultant errors are used to drive the radar servos. During this test, no target is acquired so the Rndz Rdr caution & warning light on panel 2 illuminates and the Master Alarm is activated.
The Radar Test switch also on panel 3, in the Rndz position, initiates test circuitry. The Range/Altitude tape indicator on panel 1 drives to show it is operational. The X-Pointer indicator also on panel 1 displays the rendezvous radar line of sight (LOS) elevation and azimuth angular rates.
097:33:25 Stafford (onboard Snoopy): Yes.
097:33:26 Cernan (onboard Snoopy): FDAI needles vary between limits. After 12 seconds, range tape drives, No Track, radar caution lights, off. Leave it where it is.
The rendezvous radar test will energize the FDAI error needles which deflect to their range limits and the Range tape meter on panel 1 drives to show normal operation. This is followed by the Rendezvous Radar No Track caution light on panel 3 illuminating to indicate the data being received is not good.
097:33:32 Stafford (onboard Snoopy): Roger
097:33:33 Cernan (onboard Snoopy): Okay, those lights are off.
097:33:36 Stafford (onboard Snoopy): Go.
097:33:37 Cernan (onboard Snoopy): Test Monitor, AGC.
The Test Monitor mode selector on panel 3 is placed in the Rndz Radar AGC position for test the radar under AGC (Automatic Gain Control) control and reading the signal strength on the meter also on panel 3. (See diagram above)
097:33:38 Stafford (onboard Snoopy): Go. 1.55.
097:33:42 Cernan (onboard Snoopy): Transmitter Power.
The Test/Monitor mode selector on panel 3 is placed in the XMTR Pwr position to provide the transmitter power output level which is displayed on the Signal Strength meter, also on panel 3. Stafford reads out the transmitter power readout as it climbs on the meter to its maximum readout.
097:33:43 Stafford (onboard Snoopy): 3, 4, 5.
097:33:48 Cernan (onboard Snoopy): Shaft Error.
The Test/Monitor mode selector on panel 3 is now placed in the Shaft Err position and the shaft error signals are displayed on the Signal Strength meter. Stafford reads out the level indicated on the meter.
097:33:50 Stafford (onboard Snoopy): [Garble] between 2.05 and 3 - 2.95.
097:33:56 Cernan (onboard Snoopy): Okay.
097:33:59 Stafford (onboard Snoopy): Trunnion is the same, 2 to 2.95.
The Test/Monitor mode selector on panel 3 is now placed in the Trun Err position and the trunnion error signals are displayed on the Signal Strength meter. Stafford reads out the level indicated on the meter.
097:34:06 Cernan (onboard Snoopy): AGC. AGC. AGC. AGC.
Using the LGC routine R04, RR/LR self-test, the computer provides suitable DSKY displays and LGC downlink information to support the self-test of either the rendezvous radar or the landing radar. the routine is initiated by keying Verb 63 Enter.]
Manual selection of the appropriate radar self-test using the Radar Test switch on panel 3 informs the LGC which radar is being tested. The DSKY will flash Verb 4 Noun 12 and display on register 1 00004 and on register 2 00001. The latter is the LGC option for the rendezvous radar. If register 2 is indicating the correct radar for this self-test the crew press Proceed on the DSKY.
The DSKY now flashes Verb 50 Noun 25 to request selection of the rendezvous radar self-test. At this point the Rendezvous Radar mode switch on panel 3 is placed in the LGC position and the Proceed button on the DSKY is depressed. The LGC now downlinks the rendezvous radar, range and range-rate outputs every second.
097:34:39 Cernan (onboard Snoopy): Rendezvous Radar, LGC.
The Rendezvous Radar mode selector on panel 3 is now placed in the LGC (Lunar Guidance Computer) position to enable the computer to automatically drive the antenna towards the target. Once the target has been acquired, the radar will automatically maintain the tracking and the No Track light on panel 3 will go off.
Rendezvous Radar Slew switch, Radar Signal Strength meter, Rendezvous Radar mode selector, Rendezvous Radar No Track caution light, Radar Test switch and the Rndz Radar, Test Monitor mode selector - LM panel 3.
097:34:43 Stafford (onboard Snoopy): Go.
097:34:44 Cernan (onboard Snoopy): Wait 10 seconds.
The DSKY now flashes Verb 16 Noun 72 to request a command whether to monitor the rendezvous radar CDU (Coupling Data Unit) angles. The crew press the Proceed button on the DSKY. The DSKY displays the shaft angle on register 1 and the trunnion angle on register 2. The respective angles are displayed to 0.01°.
The DSKY now flashes Verb 16 Noun 78 to request a command whether to monitor the simulated range (in nautical miles to the CSM), range-rate (between LM and CSM in f.p.s.) and time from Tig (in minutes and seconds) on the three registers respectively. The crew press the Proceed button on the DSKY.
097:34:58 Young: Snoopy, Charlie Brown.
097:35:00 Stafford (onboard Snoopy): Go ahead, John.
097:35:01 Young: Roger. The EVA preparation is complete.
Young has been busy stowing the centre couch and fitting EVA guards / handrails that protect the CM main instrument panels should the two astronauts need to make an EVA transfer between the two spacecraft due to either the inability to redock after solo ops or to clear the docking tunnel following redocking. The LM crew would don their OPS to provide breathable oxygen for the transfer in pressurized suits out of the LM front hatch, up the front of the LM and across to the CM main hatch, using a series of hand rails. This emergency EVA procedure was practiced in part by the Apollo 9 LMP, Rusty Schweickart.
Photo of the CM main panel EVA guards on Apollo 9. Crop of AS09-20-3103.
Diagram showing the EVA that would be route taken to transfer from the LM to the CM should the docking tunnel not be usable.
097:35:04 Stafford (in Snoopy): Okay. Good show.
097:35:06 Duke: Charlie Brown, Houston. We're concerned about this yaw bias in the LM and apparent slippage of the docking ring. We'd like you to disable and keep disabled all roll jets until after undocking. Over. And undocking attitude - We will not maneuver to the undocking attitude. Just hold what we've got. Over.
097:35:31 Young: Roger. Okay. Fine.
097:35:38 Duke: And, Snoop, we got 3 minutes 50 seconds to LOS, Over.
097:35:47 Stafford (in Snoopy): Roger. 3:50 to LOS.
097:35:49 Duke: And we'll see both Snoop and Charlie Brown at 98 25.
097:35:57 Stafford (in Snoopy): Alrighty. Real fine, Charlie.
097:36:02 Cernan (onboard Snoopy): What's the tape meter say, Tom?
097:36:04 Stafford (onboard Snoopy): Tape meter says 195.5. And the range rate is reading 479.
097:36:18 Duke: Okay. Charlie Brown and Snoop, 3 minutes going over the hill. You're Go for undocking, and we'll see you around the other side.
097:36:28 Stafford (in Snoopy): Roger.
097:36:29 Young: Roger.
097:36:42 Stafford (onboard Snoopy): Wow!
097:36:52 Stafford (onboard Snoopy): Okay, Geno.
097:36:53 Cernan (onboard Snoopy): Okay. You got all those?
097:36:56 Stafford (onboard Snoopy): Yes. Next thing is VERB 34, isn't it?
The rendezvous radar self-test is now complete using the LGC. The crew key Verb 34 Proceed to terminate the test.
097:37:04 Cernan (onboard Snoopy): Radar Test, Off?
097:37:05 Stafford (onboard Snoopy): Radar Test, Off?
The Radar Test switch on panel 3 is now placed in the Off position. The No Track light will now illuminate.
097:37:06 Cernan (onboard Snoopy): No Track light, On.
097:37:07 Stafford (onboard Snoopy): Yes.
097:37:08 Cernan (onboard Snoopy): Crosspointer, Center.
As the rendezvous radar self-test has now been completed, the crosspointer displays on panels 1 & 2 return to their null position in the centre of the display.
097:37:10 Stafford (onboard Snoopy): Right.
097:37:11 Duke: Snoop - correction - Charlie Brown, Houston. Try it on docking if it is apparent that the LM has - interface has slipped around to about 6 degrees; do not undock, and let's come around, again and look at it. Over.
097:37:28 Stafford (onboard Snoopy): Okay.
097:37:29 Young: Roger.
097:37:34 Stafford (onboard Snoopy): Okay. There it went out. Next one, Verb 41, Noun 72.
The No Track light now goes off. Verb 41 Noun 71 commands the coarse alignment of the rendezvous radar. It drives the rendezvous radar shaft and trunnion to angles specified by the crew. The DSKY now flashes Verb 21 Noun 73 requesting the crew enter the required rendezvous radar shaft and trunnion angles. The desired trunnion angle is keyed in first to the nearest 0.01° and is displayed on register 1. This is followed by the crew keying the desired shaft angle to the nearest 0.01° and is displayed on register 2. Verb 04 Noun 12 now flashes on the DSKY with register 1 displaying the LGC option code for the assumed designation mode. Register 2 displays the LGC assumed option, either 00001 for lock on to target or 00002 continuous designation. If the crew agree with the LGC assumptions they key Proceed. If they disagree with the mode indicated on register 2, they key Verb 22 Enter and key the desired mode code. The coarse align Verb 41 is displayed. The Program Alarm light will illuminate if the desired LOS (line of sight) is not within the limits of either rendezvous radar mode. If the crew wish to see the associated alarm code they key Verb 05 Noun 09 to identify the failure. The alarm code 00502 will be displayed, indicating a bad rendezvous radar gimbal angle input. If no alarm is triggered, the crew key Verb 41 to exit the procedure.
097:37:35 Lunney (Flight Director): Charlie, let them know it's 3½ (degrees of slippage) now.
097:37:39 Duke: Roger. Your yaw bias right not - The slippage is 3½ degrees right now, so about double what you've got, and if it does that far, do not undock. Over.
097:37:44 Stafford (in Snoopy): There.
097:37:50 Young: Up rate?
097:37:51 Stafford (in Snoopy): No, no. You want to designate it Down, babe.
097:37:56 Stafford (in Snoopy): There you go. There you go. Plus - plus 283. There you - there - there it goes - right where it should be.
097:38:25 Cernan (in Snoopy): Okay, babe. There it is. Pull your...
097:38:28 Stafford (in Snoopy): Pull the Rendezvous...
097:38:29 Cernan (in Snoopy): ...pull your Rendezvous Radar breaker, Open.
097:38:32 Stafford (in Snoopy): Okay. Go.
097:38:34 Cernan (in Snoopy): AC Bus, Rendezvous Radar, Open.
The AC Bus A Rndz Rdr circuit breaker is pulled to remove AC power from the rendezvous radar.
097:38:36 Stafford (in Snoopy): Go.
097:38:38 Cernan (in Snoopy): Verb 44, Enter.
Verb 44 Enter terminates the rendezvous radar continuous designate option initiated when the crew entered Verb 41 Noun 72 at 097:37:34 and disables the rendezvous radar CDU error counters and initiates routine 25.
097:38:44 Stafford (in Snoopy): 97:34.
097:38:48 Cernan (in Snoopy): Oh, my golly.
097:38:50 Stafford (in Snoopy): Go to the AGS CAL. Okay. What can I do for you?
The crew now initializes the calibration of the AGS (Abort Guidance Subsystem). This is involves calibrating the AGS gyros and accelerometers. This has to occur at least 25 minutes after the AGS was initialized.
With vehicle in PGNS Att Hold, maneuver vehicle via ACA until DSKY display of ICDU angles read approximately 22. 5 degrees away from 0, 45°, 90°, 135°, etc., in all three channels. Perform IMU CDU zero. Wait at least 20 seconds before proceeding to step 4. As long as all gimbal angles are more than 11. 25° away from 0°, the CDU zero and subsequent "count-up" (requires a maximum of 20 seconds) exercises all of the CDU "fine" switches and it is highly unlikely that fine switching transients will occur during calibration. The RCS are inhibited.
The LMP enters the calibration mode via DEDA (Data Entry and Display Assembly) entry 400 + 60000 (Gyro and accelerometer calibration). Wait at least 35 seconds. Return the vehicle to PGNCS Att Hold. Wait two minutes before proceeding. Once again the RCS is inhibited. Remain in this state until calibration is complete. If during the last minute of calibration it would be necessary to manually command an RCS jet firing to prevent a "coarse" CDU transient in any channel (ICDU angles crossing 0°, 45°, 90°, 135°, etc.) then manually exit the calibration via DEDA entry 400 + 00000 (Attitude hold). Normal completion of the calibration is signified by the DEDA display showing 400 + 00000.
097:39:01 Cernan (onboard Snoopy): John, are you going to be maneuvering or are you fixed now?
097:39:02 Stafford (onboard Snoopy): No, he's fixed.
097:39:04 Young: Okay. I've stopped maneuvering.
097:39:06 Cernan (onboard Snoopy): Okay. I'll go into the AGS CAL, and I'll tell you when you have to disable thrusters. Okay?
097:39:11 Young: Roger.
097:39:16 Stafford (onboard Snoopy): While Geno's going through this, according to what we had originally, John, I think you're fairly near the undocking attitude that we originally had, aren't you?
097:39:24 Young (onboard): Yes.
This is Apollo Control at 97 hours, 39 minutes. We have Loss of Signal as Apollo 10 goes behind the Moon. Due to reacquire Apollo 10 at 98 hours, 25 minutes, 42 seconds. During the early part of this 11th revolution, just after AOS, the crewmen were attempting hatch integrity tests on both Charlie Brown and Snoopy - found they were unable to vent the tunnel due to a problem in a vent valve in the top of Charlie Brown. We passed up procedure which, in effect, was to reduce the pressure in Snoopy to 3½ pounds per square inch through the forward hatch, through Snoopy's forward hatch. Bleeding off the pressure through that hatch. This in turn pulled the pressure down in the tunnel giving a Delta-P, or differential in pressure between the two, of 1½ pounds per square inch. In this way we were able to check and verify the hatch integrity for Charlie Brown. Tom Stafford and Gene Cernan then repressurized Snoopy and verified the hatch integrity for that spacecraft. The K factor, about which you heard considerable conversation is timing information for the abort guidance system [AGS], the secondary guidance system in the lunar module. We passed up an undocking time of 98 hours, 22 minutes that's Just a couple of minutes prior to acquisition of signal on the next revolution, the 12th revolution. We passed up a separation time of 98 hours, 47 minutes, 16 seconds. The separation maneuver will be performed by Charlie Brown at 2½ feet per second radially down, with the RCS thrusters, puts the vehicle in the mini football starting the separation for the rendezvous. You heard Gene Cernan calling out the checklist for Tom Stafford during the Reaction Control System checkout, both cold and hot firings and pressurization of that system. And Tom's report that the thrusters are nice and crisp and he thinks they are in good shape. We've given Charlie Brown and Snoopy a Go for undocking. Along toward the end of this pass, you may have heard John Young report that EVA preparations were completed; there's no Extra Vehicular Activity planned, of course, on this mission but these preparations are done for contingency EVAs, which would be the only method Tom Stafford and Gene Cernan would have to get back to the Command Module in case it was impossible to dock the two vehicles. And just before we lost signal, we informed the crew that there was a bias of about 3½° in the docking interface. We asked them to keep a look at it, and if this interface slipped to 6 degrees, to not undock, to stay docked until they came back in acquisition. This is Mission Control, Houston. At 97 hours, 44 minutes; we will pass on the information about the start of change of shift news conference as soon as it is available.
097:39:25 Stafford (onboard Snoopy): It won't take much in stationkeeping to work it out. I hope those cats know what they're talking about - about putting that load on the probe when it extends - I think they probably are, because as soon as that starts to crack, that pressure should vent ..
097:39:39 Young (onboard): Yes, I know. We're almost at the undocking attitude, except we should be rolled 180.
097:39:47 Stafford (onboard Snoopy): Okay. Okay. Now, are you going to roll over 180 after we undock, then?
097:39:53 Young (onboard): No. When I get - The first thing I do when I undock is roll back right side up. So I'm okay.
097:39:59 Stafford (onboard Snoopy): We must be okay like we are, huh?
097:40:01 Young (onboard): No, you'll have to figure out what the heck you're going to do. I'll be danged if I know.
097:40:05 Stafford (onboard Snoopy): Well, look, babe, I'm just going to stay right in front of you .
097:40:09 Young (onboard): Okay.
097:40:11 Stafford (onboard Snoopy): And if I'm right side up, the heck with it. I'll just go around like that. Don't worry about us. We don't want to waste any fuel. And if you just hold your attitude, when you release us, all I'm going to do is yaw right, and pitch - I'll yaw right and then pitch up. We should be face to face, then.
097:40:32 Young (onboard): Okay. We've got a small right roll going. Now I don't know where we'll be when we get there.
Due to the apparent slippage at the docking interface, MCC-H has recommended that Young doesn't perform any roll manoeuvres until the two spacecraft have undocked. The crew are concerned about what attitude they will be in at the time of undocking. They have concluded, it will be whatever it is at that time and the LM will just hold station in front of the CSM and let Young manoeuvre around them prior to assume the separating attitude.
097:40:38 Stafford (onboard Snoopy): Okay.
097:40:42 Cernan (onboard Snoopy): Okay, John. I'm at the - I'm at the point where I got to - my AGS calibration to do so - you've got to maneuver - you know, to that place where you're less than 0.1 degree per second - and we got those...
Inflight gyro and/or accelerometer calibration must only be performed during free flight. Attitude rotation rate should be less than 0.1 degree per second, this being controlled by the CSM. MCC-H has recommended that Young doesn't perform any roll manoeuvres which precludes roll control.
097:40:54 Stafford (onboard Snoopy): He can't.
097:40:55 Cernan (onboard Snoopy): You can't do it, huh?
097:40:56 Stafford (onboard Snoopy): No.
097:40:58 Young (onboard): No, they told me not to do it.
097:40:59 Stafford (onboard Snoopy): No. Our tunnel ring is slipping right. now, so we can't do it, so we'll just have to skip.
097:41:08 Cernan (onboard Snoopy): Find out where we are now. Tom, and that thing anyway - I'll just do it anyway. Going out to 1620.
097:41:20 Stafford (onboard Snoopy): See, he's drifting.
097:41:36 Cernan (onboard Snoopy): We can't do on AGS CAL test, huh?
097:41:38 Stafford (onboard Snoopy): That's right. That little old Mylar just might screw up a few things around here.
Stafford is associating the lost Mylar insulation with the docking ring slippage. With the lack of roll control of the combined spacecraft, the AGS calibration has to be terminated.
097:41:50 Stafford (onboard Snoopy): Okay. The only thing I've got left on my side is DPS pressurization and checkout.
097:41:55 Cernan (onboard Snoopy): Well, shoot, if I can't do this, there ain' t much sense in worrying about it.
097:41:58 Stafford (onboard Snoopy): No.
097:42:01 Cernan (onboard Snoopy): Okay, let's pressurize the damn DPS.
097:42:03 Stafford (onboard Snoopy): Okay, John, we're going; to Go pressurize the descent stage, here. Okay.
097:42:09 Cernan (onboard Snoopy): Let me check these. Press - temperature is Go.
097:42:23 Cernan (onboard Snoopy): Oxidizer is barely Go, but that's alright.
097:42:31 Cernan (onboard Snoopy): No. it isn't, it has plenty. Go
097:42:59 Cernan (onboard Snoopy): Descent Helium Reg 1, gray.
The Descent Helium Reg 1 talkback indicator on panel 1 displaying grey, indicates the helium primary line solenoid valve, which is controlled by the Descent He Reg 1 switch also on panel 1, is open.
097:43:00 Stafford (onboard Snoopy): Go.
097:43:01 Cernan (onboard Snoopy): 2 is barber pole.
The Descent Helium Reg 2 talkback indicator on panel 1 is displaying barber pole indicating the helium secondary line solenoid vale is closed.
Descent Helium Reg 1 & 2 switches and talkbacks - LM panel 1.
097:43:02 Stafford (onboard Snoopy):Yes.
097:43:03 Cernan (onboard Snoopy): Come and Open my ED Logic, Tom.
The ED Logic PWR circuit breakers are on panels 11 and 16. These provide DC power to the He Press Des Start switch on panel 8.
ED Logic Power circuit breakers - LM panel 11.
ED Logic Power circuit breakers - LM panel 16.
097:43:06 Stafford (onboard Snoopy): Okay.
097:43:09 Cernan (onboard Snoopy): Master Arm, On.
097:43:12 Stafford (onboard Snoopy): Master Arm is coming on.
The Master Arm switch on panel 8 is placed in the On position enabling activation of all LM explosive devices by actuating redundant relays that route power to EDS (Explosive Device Subsystem) buses.
097:43:21 Cernan (onboard Snoopy): Okay. Descent Propellant Isolation Valve, Fire.
The Des Prplnt Isol Vlv switch on panel 8 in the Fire position actuates the descent fuel and oxidizer compatibility explosive valves to permit ambient helium to pressurize the fuel and oxidizer tanks.
097:43:25 Stafford (onboard Snoopy): Stand by.
097:43:27 Stafford (onboard Snoopy): I heard something. Didn't you?
097:43:28 Cernan (onboard Snoopy): Yes, I heard something. Helium Pressure/Descent Start, Fire.
The He Des Start switch is placed in the Fire position, which fires the ambient helium explosive isolation valve that permits helium from the descent ambient helium tank to prepressurize the descent propulsion section.
097:43:34 Cernan (onboard Snoopy): Hey, wait a minute.
097:43:36 Stafford (onboard Snoopy): Yes.
097:43:39 Stafford (onboard Snoopy): Okay. Master Arm. Off.
The Master Arm switch on panel 8 is returned to the Off position removing power from the redundant relays that serve the EDS buses.
Master Arm, Des Prplnt Isol Vlv and He Press Des Start switches - LM panel 8.
097:43:43 Young (onboard): [Garble] thrusters?
097:43:45 Stafford (onboard Snoopy): Nope. Tell me when it's pressurized.
097:43:47 Cernan (onboard Snoopy): We're pressurizing...
097:43:48 Stafford (onboard Snoopy): Okay.
097:43:49 Cernan (onboard Snoopy): ...the DPS. John.
097:43:50 Stafford (onboard Snoopy): Master Arm coming Off.
097:43:55 Cernan (onboard Snoopy): God dang, that Master Arm, Off. My Logic is going Closed.
The ED Logic PWR circuit breakers are on panels 11 and 16 are now closed.
097:44:07 Cernan (onboard Snoopy): Propellant Temperature Monitor. Okay, that's Go. Helium Monitor, 440.
The Prplnt Temp/Press Mon switch on panel is firstly placed in the Des 1, then Des 2 and finally returned to the Des 1 position. The temperature of both the descent oxidizer and fuel can then be read of the strip meter also on panel 1. The Helium Mon-Des mode selector on panel 1 is placed in the Des Amb Press position. The Main Propulsion Helium digital indicator also on panel 1 displays the pressure in the descent ambient helium bottle. The readout should read between 200 and 1750 psia. Onboard, Cernan reads out the pressure as 440 psia.
Prplnt Temp/Press Mon switch, Fuel and Oxid Temp strip meter, Helium Mon-Des mode selector, and Main Propulsion Helium digital indicator - LM panel 1.
Lunar Module descent stage propellant, oxidizer and Helium tanks.
097:44:31 Cernan (onboard Snoopy): You want to deploy our landing gear?
097:44:33 Stafford (onboard Snoopy): Alright...
097:44:34 Cernan (onboard Snoopy): Do it.
097:44:35 Stafford (onboard Snoopy): Let's do it.
097:44:38 Stafford (onboard Snoopy): John, we're ready to deploy our landing gear.
097:44:41 Young (onboard): Roger, [garble].
097:44:43 Cernan (onboard Snoopy): Okay, Tom, circuit breaker (11) , ED Landing Gear Flag, Closed, and your Logic Power, Open.
The ED LDG Gear Flag circuit breaker on panel 11 is closed providing DC power to the IS (Instrumentation Subsystem) to provide control of the Ldg Gear Deploy flag. The Logic Pwr A circuit breaker remains open.
ED Ldg Gear Flag & Logic Pwr A circuit breakers - LM panel 11.
097:44:49 Stafford (onboard Snoopy): Okay.
097:44:52 Cernan (onboard Snoopy): Master Arm, On. I can't catch it, it's dark anyway, so...
Once again the explosive device Master Arm switch is placed in the On position.
097:44:58 Stafford (onboard Snoopy): It's - to heck with it. Let's keep on.
097:44:59 Cernan (onboard Snoopy): Go ahead.
097:45:00 Stafford (onboard Snoopy): Okay, ready.
097:45:03 Cernan (onboard Snoopy): Wait a minute. Landing Gear Deploy, Fire.
The LDG Gear Deploy switch on panel 8 is placed in the Fire position. This actuates explosive devices that release the stowed landing gear. The Ldg Gear Deploy talkback indicator changes to Gray once indication is received from all four landing gear assemblies, confirming the full deployment.
Ldg Gear Deploy switch and talkback indicator - LM panel 8.
097:45:08 Stafford (onboard Snoopy): Okay, your B is Closed, A is Open, right?
Stafford is confirming the position of the Logic Pwr A and Logic Pwr B circuit breakers. Only the Logic Pwr B circuit breaker on panel 16 is closed to provide dc power to the LDG Gear Deploy switch.
097:45:09 Cernan (onboard Snoopy): Yes. Stand by.
097:45:12 Stafford (onboard Snoopy): The gear is coming down, John.
097:45:19 Stafford (onboard Snoopy): Looks like we've got four in the green, babe.
097:45:21 Cernan (onboard Snoopy): I don't know how we know it, but...
097:45:27 Cernan (onboard Snoopy): Logic Power, Closed?
The crew are unsure the landing gear has deployed. Cernan is looking for confirmation that the Logic Pwr B circuit breaker has been closed.
097:45:32 Stafford (onboard Snoopy): Yes. Fire the gear again.
097:45:35 Cernan (onboard Snoopy): Landing Gear Deploy, Fire, again.
The LDG Gear Deploy switch is once again placed in the Fire position in a second attempt to deploy the landing gear.
097:45:36 Stafford (onboard Snoopy): Yes.
097:45:37 Cernan (onboard Snoopy): Did you do it?
097:45:38 Stafford (onboard Snoopy): Yes. Master Arm, Off.
097:45:40 Cernan (onboard Snoopy): Master Arm, Off. Landing Gear Flag, Open?
097:45:44 Stafford (onboard Snoopy): Yes.
097:46:04 Cernan (onboard Snoopy): Can't get an AGS gyro drift check, I guess. Not when we're moving like that.
Cernan is referring to the inability to complete the AGS calibration due to the docking ring slippage.
097:46:09 Stafford (onboard Snoopy): No. I'm going to go ahead - we undock at 98:22, right?
097:46:29 Cernan (onboard Snoopy): 98:22, Yes.
097:46:32 Stafford (onboard Snoopy): Is there anything else we need in this activation?
097:47:12 Cernan (onboard Snoopy): How about setting up my orb rate here in a minute.
097:47:14 Stafford (onboard Snoopy): Yes.
097:47:15 Cernan (onboard Snoopy): Wait until this update gets in.
097:48:01 Stafford (onboard Snoopy): Oh, shoot!
097:48:10 Young (onboard): Hey, listen, you guys. I think this thing is off about 3 degrees. Maybe it must be steerable. I can't really - it looks Okay.
The docking ring slippage was now about 3 degrees.
097:48:17 Stafford (onboard Snoopy): I think we are in good shape holding here, John. How's the tunnel pressure?
097:48:28 Young (onboard): I still have 810.
097:48:30 Stafford (onboard Snoopy): Okay, it looks like it's holding, It looks like those things should lock in pretty good again. Right? When we - the solar...
097:48:38 Young (onboard): Yes.
097:48:39 Stafford (onboard Snoopy): [Garble] solar corona.
097:48:40 Cernan (onboard Snoopy): What did that do to our alignment?
097:48:53 Stafford (onboard Snoopy): Have to pick it up again. Look at the solar corona there, Geno. It's a whitish yellow.
097:49:07 Cernan (onboard Snoopy): Yes.
097:49:08 Stafford (onboard Snoopy): John, I got the solar corona out here and the sun is going to be coming up shortly.
097:49:13 Young (onboard): Roger.
097:49:16 Cernan (onboard Snoopy): Where you looking? Let's see.
097:49:17 Stafford (onboard Snoopy): Right through there. Can you look out my window?
097:49:20 Cernan (onboard Snoopy): Yes.
097:49:23 Stafford (onboard Snoopy): Just at the rims, with some of the mountain peaks are starting to get lighted. Beautiful view.
097:49:29 Cernan (onboard Snoopy): Watch it when it pops. It'll really hit you. Boy, that is beautiful, isn't it?
097:49:33 Stafford (onboard Snoopy): Here come da Sun.
097:49:35 Cernan (onboard Snoopy): Some of those peaks are lighted.
097:49:37 Stafford (onboard Snoopy): Yes.
097:49:46 Stafford (onboard Snoopy): Here it comes. Watch out. Boom.
097:49:49 Cernan (onboard Snoopy): Wow. Man, I tell you. When it comes, it comes.
097:49:53 Stafford (onboard Snoopy): Why don't I go ahead and put mine back here, Geno?
097:50:25 Stafford (onboard Snoopy): You got the final there. Let's verify these circuit breakers.
097:50:34 Cernan (onboard Snoopy): Okay.
097:50:37 Stafford (onboard Snoopy): We got about 31 minutes to undocking, John. We'll undock early so we can get squared away.
097:50:41 Cernan (onboard Snoopy): How about setting up my 8-ball, Tom, as soon as I verify it here.
097:50:45 Stafford (onboard Snoopy): Yes.
097:50:51 Young (onboard): Set it to what, Geno?
097:50:56 Cernan (onboard Snoopy): Sorry. John. I didn't hear you. What did you say?
097:50:58 Young (onboard): [Garble] where you want me to set up?
097:51:00 Cernan (onboard Snoopy): Where you want him set up? I don't know. Tom asked you something. I'm not sure what it was.
097:51:04 Stafford (onboard Snoopy): Tell him to stand by.
097:51:05 Cernan (onboard Snoopy): Stand by a minute.
097:51:21 Stafford (onboard Snoopy): Gene, I'm set up and ready for the undocking, babe.
097:51:43 Stafford (onboard Snoopy): I'm going to put this back in the data file.
097:52:02 Cernan (onboard Snoopy): Got your Balance Load and Cross Ties both closed, huh? Your Bus Tie, rather.
The EPS Cross Tie-Bal Loads circuit breaker on panel 11 for the CDR and panel 16 for the LMP, tie each feeder bus system to the opposite dc bus through its EPS Crosstie-Bal Loads circuit breaker. By doing so it provided a redundant path for IS subsystem sensors and EPS display circuit breakers up to a load of 30 amps.
The EPS Cross Tie Bus circuit breakers also on panels 11 and 16 perform the same function as the EPS Cross Tie-Bal Load breakers but up to a load of 100 amps.
EPS Cross Tie Bus circuit breakers - LM panel 11.
EPS Cross Tie Bus circuit breakers - LM panel 16.
097:52:06 Stafford (onboard Snoopy): Yes.
097:52:10 Cernan (onboard Snoopy): Your Bus Tie isn't Closed, is it?
097:52:12 Stafford (onboard Snoopy): Yes.
097:52:13 Cernan (onboard Snoopy): Okay.
097:52:14 Stafford (onboard Snoopy): No. My Bus Tie isn't. I'm sorry.
097:52:15 Cernan (onboard Snoopy): Leave those - leave those closed.
097:52:42 Stafford (onboard Snoopy): I've got to have water. I'm thirsty as hell.
097:52:50 Cernan (onboard Snoopy): I didn't get a very good agreement on this at all. Look at that. I never have.
097:53:00 Cernan (onboard Snoopy): I never did get agreement.
097:53:06 Young (onboard): Hey, can you guys fix that yaw thing?
097:53:11 Cernan (onboard Snoopy): How are we going to fix it?
097:53:13 Stafford (onboard Snoopy): John, no problem. See, we'll just keep what we've got, and then as soon as we go into nighttime and align we'll be in good shape. Okay?
097:53:20 Young (onboard): Okay. Boy I'm sure sorry. I don't know what the heck did that.
097:53:33 Stafford (onboard Snoopy): Probably what got to us is this doggone insulation.
097:53:53 Cernan (onboard Snoopy): That AGS is bad, babe. I don't like that. That's - that's - That's 40 degrees. How about setting up my Orb-rate ball, babe?
To ensure they have a display of the local vertical attitude on the FDAI, the ORDEAL (Orbital Rate Display Earth And Lunar) is configured to be Orb Rate-Lunar, providing input to the LMP's FDAI on panel 2. The ORDEAL is used after obtaining the LM attitude with respect to the local lunar horizontal from the LGC. The LMP's FDAI will be slewed to display this attitude. The ORDEAL then torques its resolvers at the lunar orbital rate, specified by the altitude set on the Alt Set control for the circular orbit of the body (Earth or Lunar) that is selected. Cernan wants an alternative display of the LM attitude should the AGS not be available.
FDAI select switch, body select switch and Alt Set rotary selector - LM Ordeal panel.
097:54:00 Stafford (onboard Snoopy): Okay.
097:54:13 Stafford (onboard Snoopy): How is it?
097:54:15 Cernan (onboard Snoopy): That's the best we got, right there.
097:54:20 Young (onboard): Hey, I don't like it...
097:54:26 Stafford (onboard Snoopy): Shit. We're drifting like mad.
097:54:27 Young (onboard): Shoot, yes.
097:54:31 Cernan (onboard Snoopy): I guess we'll just have to wait and see on that one, babe. I don't know. We'll try it again. Let's go through our normal procedures, and if we get lost, we'll go back to VHF Simplex.
097:54:41 Young (onboard): Okay.
097:54:51 Stafford (onboard Snoopy): José.
097:54:53 Young (onboard): I don't know. Wait a minute.
097:54:54 Stafford (onboard Snoopy): What - How far are you going to have to maneuver. If I - Once we get squared away, all you have to do is maneuver in roll. It doesn't hurt us a bit. Are you going to have to maneuver much in pitch and yaw?
097:55:05 Young (onboard): About 10 degrees.
097:55:07 Stafford (onboard Snoopy): Ah, hell. That won't hurt us a bit. You want to undock 10 minutes early? And get squared away? Or 5 minutes - 5 minutes should do it.
097:55:16 Young (onboard): I think we should.
097:55:18 Stafford (onboard Snoopy): It's up to you. I'm sorry. I inadvertently hit the stick.
097:55:35 Cernan (onboard Snoopy): You have Verb 76 in now?
Cernan is confirming with Stafford when he has enabled the RCS minimum impulse mode of the DAP, by keying Verb 76, Enter on the DSKY. The Guid Cont switch on panel 1 must also be in the PGNS position and the Mode Control PNGS switch on panel 3 at Att Hold.
097:55:39 Stafford (onboard Snoopy): Oh, you put it in.
097:55:40 Cernan (onboard Snoopy): Huh?
097:55:41 Stafford (onboard Snoopy): You put it in, huh?
097:55:42 Cernan (onboard Snoopy): I sure don't like that angle.
097:55:-- BEGIN LUNAR REV 12
Previous Index Next
Day 4, part 16: Rest and Preparation for Solo Operations Journal Home Page Day 5, part 18: Undocking & DOI, Snoopy goes solo