Apollo 8 is only four and a half hours away from the Moon. More accurately, they have that time to wait before their current trajectory brings them to the point of closest approach, the pericynthion. At that time, they have two choices. They could do essentially nothing and swing around the Moon to be sent on a path back to Earth (an important safety reason why they are on this trajectory). Instead, what they plan to do is fire their large SPS engine long enough to slow them down and let the Moon's gravity keep them in orbit around it. They will then be the first humans to come under the gravitational lock of another world as they begin twenty hours and ten orbits of reconnaissance of the lunar surface. They will also be utterly dependent on their SPS firing again to bring them home and avoid a grisly end 400,000 kilometres from Earth.
By the Flight Plan, Frank Borman, the mission's commander, should be keeping watch. Jim Lovell (CMP) and Bill Anders (LMP) should be asleep. However, the crew have found it difficult to maintain the sleep/wake cycle demanded by the constant watch system because of the cramped conditions and the proximity of their active crewmate. All three crewmembers seem to be awake or nearly so despite Bill having taken a sleeping pill ninety minutes ago. Over the next few hours, activity will begin to pick up as they prepare for the LOI-1 (Lunar Orbit Insertion) burn.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control, Houston at 64 hours, 22 minutes, 24 seconds now into the flight, Apollo 8. The Apollo 8 spacecraft at the present time; 12,761.5 nautical miles [23,634.3 km] away from the Moon. Its current velocity relative to the Moon; 4,288.9 feet per second [1,307.3 m/s]. Glynn Lunney's team of Black - Black Team of flight controllers is now aboard. He brought the team up with amber lights, and went around the room and discussed our current status. Meanwhile we have about 15 seconds of conversation with the crew. The conversation relative to present trajectory and tracking. We'll play that now.
So at 64 hours, 22 minutes, 37 seconds, you heard the discussion - our tracking looks - looks great. This is Apollo Control, Houston.
065:24:07 Lovell: Roger, Houston. This is Apollo 8. Loud and clear. How me?
065:24:11 Carr: Roger. Loud and clear, Jim.
Very long comm break.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control, Houston at 65 hours, 48 minutes now into the flight of Apollo 8. At the present time our displays show us that we're 9,128.8 nautical miles [16,906.5 km] away from the Moon. Our velocity reads 4,460.3 feet per second [1,359.5 m/s]. We've only had brief conversations with Apollo 8 since our last anouncement. Primarily communication checks and we'll play that tape for you now.
Apollo Control, Houston. Meanwhile we've been provided some refined numbers for Loss of Signal and Acquisition of Signal as we proceed on our Lunar Orbit Insertion burn number one. We should lose Apollo 8 communications behind the Moon at 68 hours, 58 minutes, 4 seconds Ground Elapsed Time. We're now looking at a time of ignition of 69 hours, 8 minutes, 5 seconds and we should reacquire at 69 hours, 31 minutes, 34 seconds. Honeysuckle should be our tracking station to acquire. At 65 hours, 15 minutes, 18 seconds into the flight; this is Apollo Control, Houston.
065:55:26 Carr: Apollo 8, Houston; with a preliminary LOI-1 PAD. Over. [Long pause.]
065:55:51 Carr: Apollo 8, Houston. Over.
065:55:57 Lovell: This is 8. Go ahead, Houston.
065:56:00 Carr: Apollo 8, Houston; with a preliminary LOI-1 PAD. Over.
065:56:09 Lovell: Roger. Stand by one.
065:56:11 Carr: Roger. Standing by. [Long pause.]
065:57:07 Lovell: Houston, Apollo 8. Ready to copy.
065:57:10 Carr: Apollo 8, this is Houston. Roger. LOI-1; SPS/G&N; 62844; minus 1.61, plus 1.29; 069:08:18.41. Copy?
065:57:52 Lovell: 8 is copying.
065:57:55 Carr: Roger, 8. Minus 2983.7, plus 0239.0, plus 0099.4; 000, 200, 005; 0169.3, plus 0060.0; 2994.9, 4:02, 2978.2. Copy? [Pause.]
065:58:12 Lovell: 8 is copying.
065:58:15 Carr: Roger, 8. 01, 068.9, 26.0, Persei Zeta, down 04.8, left 0.5. The remainder is Not Applicable. Sirius, Rigel, set of stars for GDG Align; 129, 155, 010; negative ullage. We'll pass the horizon window data later. Over. [Pause.]
An interpretation of the PAD follows:
Purpose: The PAD gives preliminary parameters for the main Lunar Orbit Insertion burn (The LOI-1 burn). As further tracking is carried out, the numbers will be refined and read to the crew later.
Systems: The burn will be made with the SPS engine under control of the Guidance and Navigation system.
CSM Weight (Noun 47): 62,844 pounds (28,506 kg).
Pitch and yaw trim (Noun 48): -1.61° in pitch, +1.29° in yaw. The SPS engine will be aligned on its gimbals to these angles to put its thrust axis through the spacecraft's centre of mass.
Time of ignition, TIG (Noun 33): 69 hours, 8 minutes, 18.41 seconds.
Change in velocity (Noun 81), fps (m/s): X, -2,983.7 (-909.4); Y, +239.0 (+72.8); Z, +99.4 (+30.3). The change in velocity is resolved into three components expressed relative to the Local Vertical frame of reference, in this case, relative to the Moon. The large negative X component indicates the retrograde nature of the burn.
Spacecraft attitude: Roll, 0°; Pitch, 200°; Yaw, 5°. The desired spacecraft attitude is measured relative to the alignment of the guidance platform. In this case the alignment will be the LOI-2REFSMMAT. The pitch value of 200° shows that the spacecraft will be aimed in an essentially engine-first attitude.
HA, expected apocynthion of resulting orbit (Noun 44): 169.3 nautical miles (313.5 km).
HP, expected pericynthion of resulting orbit (Noun 44): 60.0 nautical miles (111.1 km). The pericynthion will be over the Moon's far side, at roughly the same position that LOI occurred; with the apocynthion occurring over the near side.
Delta-VT: 2,994.9 fps (912.8 m/s). This is the total change in velocity the spacecraft would experience. (It is a vector sum of the three components given above.)
Burn duration or burn time: 4 minutes, 2 seconds.
Delta-VC: 2,978.2 fps. This value is entered into the Delta-V display of the EMS panel allowing backup control of the engine in case there is a problem with the G&N system. This value is less than Delta-VT because the EMS cannot take account of the extra thrust that the engine gives after shutdown, the tail-off impulse, for which the G&N system does account.
Sextant star: Star 10 (Mirfak, or Alpha Pegasi) visible in sextant when shaft and trunnion angles are 68.9° and 26.0° respectively. This is part of an attitude check.
Boresight star: Zeta Persei is used for a second attitude check which is made by sighting through the COAS (Crew Optical Alignment Sight).
COAS Pitch Angle: Down 4.8°.
COAS X Position Angle: Left 0.5°.
GDC Align stars: Stars to be used for GDC Align purposes are Sirius and Rigel. This would be used in the event that the IMU could not be used for aligning the gyro assemblies. The spacecraft would be manoeuvred so that the two stars could be viewed in the scanning telescope in a certain configuration. On achieving this, the spacecraft would be in a known attitude, the same one given in the PAD, allowing the GDCs (Gyro Display Couplers) to be manually aligned.
The final note in the PAD is that there will be no ullage burn as the tanks are full.
065:59:15 Lovell: Roger. Preliminary LOI-1 PAD as follows: SPS/G&N; 62844; minus 1.61, plus 1.29. Are you copying?
065:59:30 Carr: Roger. Copying.
065:59:35 Lovell: 069:08:18.41; minus 2983.7, plus 0239.0, plus 0099.4; 000, 200, 005; 0169.3, plus 0060.0; 2994.9, 4:02, 2978.2; 01, 068.9, 26.0; Persei Zeta, down 04.8, left 0.5. The remainder not applicable. Sirius, Rigel; 129, 155, 010. No ullage. We'll pass up the remainder up later.
066:00:31 Carr: Roger, Jim. One question - we talked about a P40 gimbal check. Would you like to do that during this maneuver to LOI-1 attitude, or would you rather hold that off until a little closer to LOI? Over. [Pause.]
Program 40 will be used to control the firing of the SPS engine. It has an associated range of procedures leading up to ignition and these are detailed in the Guidance Checklist, pages G-43 to G-49. Midway down page G-45 are the procedures to check the operation of the TVC (Thrust Vector Control) system. The SPS engine is mounted on gimbals that allow its thrust vector to be altered both before and during a burn. This is to keep the thrust acting through the spacecraft's centre of mass, even as it changes due to depleting propellants. This system is crucial to the safe operation of the SPS as any gross misalignment of the thrust vector would cause the ship to tumble during the burn. Failure of the TVC check would cause an abort of the LOI burn and direct return to Earth.
By the checklist, the TVC check comes only about six minutes before ignition, well after the spacecraft manoeuvres to its proper attitude for the burn and out of sight of Earth. Mission Control are suggesting they do the check much earlier, possibly so the spacecraft is still in view of Earth when the check is made, allowing engineers to watch its progress.
066:00:57 Lovell: Let me check on that. Wait one, Houston.
066:02:47 Lovell: Roger. We could make this gimbal check as a [part of a] maneuver to the LOI attitude.
066:02:53 Carr: Roger. [Pause.]
066:03:00 Lovell: Understand that you'll load us up with the LOI-1 PAD and we'll run through P40 as far as the gimbal check.
066:03:08 Carr: Roger. That's what we heard you were going to do on it. Are you going to run both the manual gimbals as well as the automatic? Over.
The TVC gimbals can aim the SPS engine under both automatic control (by the computer) and manual control (where Jim would steer the spacecraft using the rotational hand controller).
066:18:42 Carr: Apollo 8, Houston. Standing by to monitor P52. Over.
066:18:51 Lovell: Roger.
Long comm break.
Apollo 8's crew have begun their preparations to enter lunar orbit. The first item in the Flight Plan is a realignment of the guidance platform using Program 52. The platform is currently aligned to the LOI-2 REFSMMAT which Jim did six hours ago. The Mission Report states that this P52 was carried out by Frank though the transcript here and in half an hour's time suggests that Jim performed it.
Their current PTC (Passive Thermal Control) roll must be stopped and the spacecraft manoeuvred to a suitable attitude. The stars he used were number 30, Menkent (Theta Centaurus), and number 32, Alphecca (Alpha Coronae Borealis), both in the southern celectial sphere. Another P52 will be carried out before LOI to ensure the platform's drift is still acceptable before committing to lunar orbit.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control, Houston at 66 hours, 14 minutes, 20 seconds now into the flight of Apollo 8. Our current distance away from the Moon; 7,980.3 nautical miles [14,779.5 km]. Our current velocity continuing to build up 4,542.1 feet per second [1,384.4 m/s]. We've passed along a preliminary LOI-1 maneuver PAD to the spacecraft. Jerry Carr conversing with Jim Lovell, the Command Module Pilot, and we'll relay that to you now.
This is Apollo Control Houston, that was the preliminary maneuver PAD passed to Apollo 8 for the LOI-1 ignition, or burn. Some of these numbers represent some slight changes and we've gleaned from the long listing, certain ones that could be considered of interest. We're looking at time of ignition at 69 hours, 8 minutes, 18 seconds. The burn, a retrograde burn, should place us in an orbit around the Moon with an apolune of 169 nautical miles, a perilune of 60 nautical miles [313 by 111 km]. The Delta-V for the burn that we're looking at would be 2,994 feet per second [913 m/s]; burn time of 4 minutes, 2 seconds. So at 66 hours, 21 minutes, 35 seconds into the flight; this is Apollo Control, Houston.
The following three lines of comm were placed in the original transcripts after 066:50:15 but without time codes. In 2004, recordings of the Apollo 8 air/ground communication made at the Honeysuckle Station, Australia by Bernie Scrivener were donated to the AFJ by his widow, Rosemary via Mike Dinn. One of these allowed the misplaced comm to be properly positioned in the transcript.
066:26:59 Lovell: Houston, Apollo 8. P52 complete.
066:27:06 Carr: Apollo 8, Houston. Roger. Copy.
Very long comm break.
066:38:10 Carr: [Garble.]
Long comm break.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control, Houston at 66 hours, 39 minutes, 52 seconds into the flight of Apollo 8. Apollo 8 drawing closer to the Moon. At this time we read a distance away of 6,848.8 nautical miles [12,684.0 km]. Our present velocity; 4,643.5 feet per second [1,415.3]. We have had only a brief conversation with the crew of Apollo 8 since our last transmission, and we'll pass that along now.
Apollo Control, Houston. Although we expect an apolune of 169.3 nautical miles [313.5 km], and a perilune of 60 nautical miles [111 km] to result from the Lunar Orbit Insertion number 1 burn, we would anticipate ignition for the 2,994-feet-per-second [913-m/s] burn at an altitude of about 70 nautical miles [130 km]. Since on our trip out the Moon is below our trajectory plane or path and as Apollo 8 approaches the Moon, we'll see a velocity build up to around 8,400 feet per second [2,560 m/s] at the time of LOI ignition. Our approach for the spacecraft - on approach, the spacecraft sort of dives toward and behind the Moon. So at 66 hours, 41 minutes, 50 seconds; this is Apollo Control, Houston.
In describing the Moon as being 'below our trajectory plane or path', the PAO is alluding to a necessary plane change that will be performed as part of the LOI manoeuvre. This plane change will put the spacecraft into a more equatorial orbit, and one that will pass over the candidate landing sites.
Readers wishing to learn more about the LOI manoeuvre can refer to Frank O'Brien's essay, Lunar Orbit Insertion.
066:42:01 Borman: Houston, how do you read? Apollo 8.
066:42:03 Carr: Apollo 8, this is Houston. Loud and clear.
066:42:11 Borman: Okay, Jerry. At 67, we're going maneuver to the LOI-1 attitude, do a sextant star check, and then we'll have to go back to PTC. I want to know if you want us to go back to the same attitudes we are at now?
066:42:24 Carr: Apollo 8, Houston. That's affirmative. Break. We're getting ready to ask you to do an erasable dump, Verb 47. We're ginning up to get ready for it now, and we'll call you as soon as we're ready to copy.
The Verb 47 call is erroneous but will be corrected to Verb 74 forthwith. This verb initialises a dump of the computer's erasable memory to Earth so engineers can analyse its contents. Six hours ago, Jim first aligned the platform to the preferred orientation for the LOI burn. As he tried to do this, he ran into problems, first with a warning about gimbal lock and second, difficulty in automatically aiming at a star. Mission Control hope to diagnose the problem by looking at the contents of the computer's memory.
Note that Frank will manoeuvre to the correct attitude for the burn, check that the sextant looks at the correct star with the PAD angles set, then manoeuvre back to retart the PTC roll. This may be to give plenty of time for the attitude check before disappearing behind the Moon.
066:42:41 Borman: Understand. Verb 47 when you call.
066:42:45 Carr: Negative; Verb 74.
066:42:50 Borman: Okay. Verb 74. [Long pause.]
066:43:43 Carr: Apollo 8, this is Houston. We're setting up for the dump now. It'll take about 3 minutes and 20 seconds once we start the dump. Over.
066:47:17 Borman: Roger. Can you point out the position of this Zeta Perseus to us a little better? We don't have it marked on our charts. We have got Mirfak, and we know Algol, but which one is Zeta Perseus?
Zeta Persei is required for the second attitude check prior to the LOI burn. With the spacecraft at the correct attitude for the burn and the COAS set to the angles given in the PAD, the star should be visible through it. Note that Zeta Persei is not one of the stars in the Apollo star list. Neither is it one of brightest stars, being around third magnitude.
066:47:29 Carr: Roger, Frank. Persei Zeta is just about exactly between Aldebaran and Mirfak. [Long pause.]
Mirfak is the brightest star in Perseus.
This star map shows the relationship of Zeta Persei with respect to Aldebaran (the reddish bright star that dominates Taurus) and Mirfak.
066:48:39 Carr: Apollo 8, this is Houston. We're ready for your CMC erasable dump. Key Verb 74 Enter. Over.
066:48:51 Borman: Roger. [Pause.]
066:49:02 Lovell: Verb 74 Enter.
066:49:05 Borman: Did you get it? [Long pause.]
066:49:24 Borman: Houston, Apollo 8. Are you getting the dump?
066:49:27 Carr: Apollo 8, this is Houston. Indications are that we're getting it; we're checking. You'll have to leave the computer alone for 3 minutes and 20 seconds. Over.
066:49:38 Borman: Roger. We are. [Pause.]
066:49:47 Carr: Apollo 8, Houston. We're getting your dump low bit rate through Honeysuckle.
066:49:55 Borman: Roger. [Pause.]
066:50:04 Carr: Apollo 8, Houston. Persei Zeta is a third magnitude star same as Enif. Over.
066:50:15 Borman: Same magnitude as Enif.
066:50:17 Carr: Affirmative. [Long pause.]
066:50:22 Borman: Okay.
As the chart above shows, Enif is a similar magnitude star just north of Zeta Persei.
066:51:14 Borman: Jerry, when are you going to send us the TEI-1 [Trans-Earth Injection] and the rest of that block data? [Long pause.]
At 067:20 in the Flight Plan, about half an hour from now, the crew are expecting Mission Control to read up three contingency PADs, TEI-1, TEI-2 and PC plus 2. The first two are for returning to Earth after one and two orbits of the Moon. The third is a burn that would be made if they do not enter lunar orbit but instead elect to return to Earth directly. This Pericynthion-plus-2-hour burn would speed their return home and ensure they land at a chosen site with recovery forces nearby. All three PADs would only be used in case of a loss of communication with the spacecraft.
066:51:30 Carr: Apollo 8, Houston. PC plus 2 does not need an update. We'll have your TEI-1 and 2 in about 10 minutes. Over.
066:51:41 Borman: Roger.
Comm break.
A PC plus 2 PAD was read to the crew seven hours ago and is still considered valid.
066:54:00 Carr: Apollo 8, Houston. The dump is complete; you can have your computer back. The reason for the dump was to investigate further the P52 anomaly you had about 4 hours ago. We'll try to have some words for you in about 20 or 30 minutes. Over.
066:54:18 Borman: You mean when it wouldn't come up with the proper star?
066:54:22 Carr: Affirmative.
066:54:26 Borman: Okay.
066:54:30 Borman: We're going to go ahead and start our maneuver to LOI-1 attitude.
066:54:34 Carr: Roger. Standing by to monitor. [Pause.]
066:54:42 Lovell: Houston, Apollo 8.
066:54:45 Carr: Houston. Go ahead.
066:54:50 Lovell: Earlier in the flight, I noticed that the auto optics wouldn't drive to the star pick-a-pair selected. For example, we - it picked Alpheratz at one time, wouldn't drive there, and we drove to a spot that had no star; and I went back and reselected the program and came back, and it worked okay.
066:55:11 Carr: Roger, Jim. Copy. [Long pause.]
066:55:26 Carr: Jim; is this anomaly you're talking about - was that 4 hours ago when we did the REFSMMAT align?
066:55:37 Lovell: This happened, I think, yesterday. When we - we were doing a regular REFSMMAT alignment. Alpheratz was the first star selected, and it didn't drive to Alpheratz; and I went in and reselected the program again, and it worked okay.
066:55:54 Carr: Okay, Jim. Thanks.
066:55:56 Borman: Jerry, this is Apollo 8.
066:55:57 Carr: Go ahead.
066:55:59 Borman: Apollo 8 here, Jerry.
066:56:01 Carr: Go ahead, Frank.
066:56:06 Borman: Our PAD here hadn't been - Roger. Our PAD hasn't been correct. I understand the gimbal angles for LOI-1 are roll 0, pitch 200, and yaw 5. Is that correct?
066:56:17 Carr: Affirmative, Frank. That is correct.
066:56:22 Borman: Thank you.
Comm break.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control, Houston at 66 hours, 57 minutes, 14 seconds now into the flight of Apollo 8. Apollo 8 now 6,077.3 nautical miles [11,255.1 km] away from the Moon. Its current velocity; 4,729.7 feet per second [1,441.6]. We've had considerable conversation over the past few moments or minutes with the crew and we'll pass that along now.
066:57:39 Carr: Apollo 8, Houston with a map update. Over.
066:57:45 Borman: Okay. Stand by a minute.
066:57:48 Carr: Roger. [Long pause.]
066:58:04 Borman: Go ahead.
066:58:07 Carr: Apollo 8, this is Houston. Map update Rev 1, slash 2: 68:58:04, 69:05:05, 69:31:41, 70:14:48. Copy?
Pages 1-18 to 1-20 of the Flight Plan include forms for entering these map updates during the orbital part of the mission.
066:59:23 Carr: Roger. Remarks: Charlie Papa 1, 71:14:57; Charlie Papa 2, 71:28:32; Charlie Papa 3, 71:47:26; Bravo 1, 72:09:42. Over.
This map update refers to events and landmarks that will be encountered during the first and second revolutions around the Moon. It is interpreted as follows:
Loss of Signal (LOS) before start of rev 1: 068:58:04. This is the time they lose contact with Earth as they go behind the Moon before the LOI burn. It occurs about 10 minutes before ignition.
Passing over the meridian of 150°W: 069:05:05. At this time, they will be passing over the eastern rim of the large far-side crater Korolev which coincides with the 150°W line of longitude. This provides a useful check of their trajectory prior to the LOI burn.
Acquisition Of Signal (AOS): 069:31:41. If the burn goes ahead as planned, this is the time the spacecraft will reappear around the Moon's Eastern limb. If LOI is abandoned, the spacecraft would reappear much earlier.
Spacecraft sunset in orbit: 070:14:48. As the spacecraft moves across the near-side face of the crescent Moon, this is the time it will pass from lunar daytime into the lunar night (i.e. into the Moon's shadow) soon after it passes over the sunrise terminator.
Loss of Signal (LOS) before start of rev 2: 070:56:36. The second lunar orbit begins at about the same place where LOI occurred on the far side of the Moon. This is the time the spacecraft will lose contact with Earth as it goes around the dark western limb.
Spacecraft sunrise in orbit: 071:00:59. After LOS, the spacecraft will come back into daylight at this time. Soon after, it will cross the Moon's sunset terminator.
Passing over the meridian of 150°W: 071:10:42.
Acquisition Of Signal (AOS): 071:39:40.
Spacecraft sunset in orbit: 072:23:17.
During their second pass across the Moon daylit hemisphere, Jim is scheduled to make four sightings through the hatch window of three control points and a landmark. There are spaces in the Flight Plan where the he can write the times of closest approach to each. The reason for this may be to do with familiarising himself with the terrain. Later, he will be using the spacecraft's optical system to take calibrated marks on these points to aid the accurate determination of their orbit and the Moon's shape.
Control Point 1: 71:14:57. Control point 1 is situated on the floor of the crater Korolev on the Moon's far side.
Control Point 2: 71:28:32. Control point 2 is a keyhole-shaped crater between the far-side craters Keeler and Beijerinck.
Control Point 3: 71:47:26. Control point 3 is near Mare Smythii, between the craters Brunner and Hansky.
Landmark Bravo-1: 72:09:42. Landmark B-1 on Mare Tranquillitatis was also known as Apollo Landing Site (ALS)-1 and Apollo 8 will treat it as such to give the crew practice with viewing and marking on it.
Another site, ALS-2, also on Tranquillitatis but further west, would be practiced on by the Apollo 10 crew and eventually visited by Apollo 11.
067:00:06 Lovell: Roger. Standby. I'll get the antenna. [Long pause.]
067:00:25 Lovell: Map update as follows, Houston: 68:58:04, 69:05:05, 69:31:41, 70:14:48, 70:56:36, 71:00:59, 71:10:42, 71:39;40, 72:23:17; Charlie Papa 1, 71:14:57; Charlie Papa 2, 71:28:32; Charlie Papa 3, 71:47:26; Bravo 1, 72:09:42.
067:01:25 Carr: Apollo 8, this is Houston. Readback is correct.
067:04:26 Carr: Apollo 8, Houston. Try to lock up an Omni for us? Over.
067:04:33 Lovell: Roger. [Long pause.]
067:04:59 Borman: How do you read now, Houston?
067:05:03 Carr: Apollo 8, Houston. Reading you loud and clear. No TM [telemetry].
067:05:11 Borman: Understand. No TM.
Comm break.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
Apollo Control, Houston. As you heard, Apollo 8 has begun its maneuver towards the LOI-1 burn attitude. Apollo 8 has started this maneuver. 'Map' by the way does not translate into 'Message Acceptance'. Paul (Haney) says it did in earlier manned flights. These numbers that were passed along are times in lunar orbit for acquisition and loss of signal for the Manned Space Flight Network. Lunar sunrise and sunset times in crossing of the Moon's prime meridian determined by the lunar sunset terminator longitude. It's almost, in fact it is 2 hours past midnight now. It's Christmas Eve and as we proceed on the last lap of our flight path toward a position where the Moon will be, Apollo 8 is actually coming to a final phase of rendezvous with the Moon. The Moon too is traveling. From the time of lift-off, the Moon will have traveled on the order of 130 (thousand) nautical miles to make good its meeting for the Lunar Orbit Insertion burn. So at 67 hours, 8 minutes, 14 seconds into the flight; this is Apollo Control, Houston.
The PAO announcer's use of the term 'prime meridian' is mistaken. The lunar prime meridian is the line between the poles that passes through the point on the surface that directly faces Earth. He is referring to a meridian (line of longitude) that is 150° west of the prime meridian. As the announcer finishes, it is two hours exactly to the LOI burn.
067:06:33 Carr: Apollo 8, Houston.
067:06:39 Borman: Go ahead, Houston. Apollo 8.
067:06:41 Carr: Roger, Frank. How far are you from your gimbal drive check? Over.
067:06:50 Borman: We're just maneuvering to the attitude now.
067:06:55 Carr: Roger, Frank. Can you lock up the High Gain at that attitude? We have a telemetry problem. Over.
067:07:04 Borman: We'll try to. I don't know if we can or not; have to wait 'til we get there.
067:07:09 Carr: Roger. Standing by.
Long comm break.
As the spacecraft is slowly manoeuvring to the burn attitude, they believe the HGA (High Gain Antenna) is not keeping the link to Earth. The omnidirectional antennae may not be powerful enough to sustain a good telemetry link with Earth. Mission Control would like telemetry from the spacecraft for the gimbal check but are happy for it to come when the correct attitude is reached.
067:12:07 Carr: Apollo 8, this is Houston. We have a handover from Honeysuckle to Guam in about two minutes.
067:12:16 Borman: Thank you.
Comm break.
067:13:29 Carr: Apollo 8, Houston. [No answer.]
067:13:47 Carr: Apollo 8, Houston. [No answer.]
067:14:22 Carr: Apollo 8, Houston. Over. [No answer.]
067:15:17 Carr: Apollo 8, Houston. Over. [No answer.]
067:16:08 Carr: Apollo 8, Houston. [No answer.]
067:16:58 Lovell: Houston, Apollo 8.
067:17:00 Carr: Apollo 8, Houston. Loud and clear. How me? [Pause.]
067:17:10 Lovell: Houston, Apollo 8.
067:17:13 Carr: Apollo 8, this is Houston. Loud and clear. How me? Over. [No answer.]
067:17:41 Carr: Apollo 8, Houston. Over. [No answer.]
067:17:54 Carr: Apollo 8, Houston. Over.
067:18:00 Borman: Go ahead, Houston. Apollo 8 here.
067:18:02 Carr: Apollo 8, this is Houston. I have TEI-1 and TEI-2 PADs. We still have no telemetry; expect to get it soon. Over.
067:18:14 Borman: Roger. You think it's a ground problem?
067:18:19 Carr: Roger. It's a ground problem; we just got it back. [Long pause.]
067:18:57 Borman: Houston, Apollo 8. Go ahead with your data. [Pause.]
067:19:05 Carr: Apollo 8, this is Houston with an LOI-1 PAD. Over.
067:19:14 Borman: Roger. Understand. LOI-1.
067:19:17 Carr: That is affirmative, LOI-1; SPS/G&N: 62844; 1 - correction - minus 1.61, plus 1.29; 069:08:19.52; minus 2984.0, plus 0239.0, plus 0105.3. Copy? [No answer.]
067:20:58 Carr: Apollo 8, Houston. Over.
067:21:02 Borman: Roger. We broke lock; did not get the Delta-VX.
067:21:08 Carr: Apollo 8, Houston. Roger. Beginning with Delta-VX: minus 2984.0, plus 0239.0, plus 0105.3; 000, 200, 005; 0169.3, plus 0060.0; 2995.4, 4:02, 2978.8. Copy?
067:22:19 Borman: Roger.
067:22:21 Carr: Roger. 01, 068.8, 25.9; Persei Zeta, down 04.8, left 0.5. The remainder not applicable. Sirius, Rigel, 129, 155, 010; negative ullage. Horizon window, ignition minus 2 minutes, 40 degrees unlit, ignition 27 degrees unlit. Over.
The PAD is interpreted as follows:
Purpose: This PAD is gives the parameters for Lunar Orbit Insertion burn 1, the burn that will slow Apollo 8 down until it is captured in orbit around the Moon. Two burns will be required before the final orbit is achieved so this is the first.
Systems: The burn will be made using the large SPS (Service Propulsion System) engine at the rear of the Service Module, under the control of the Guidance and Navigation system.
CSM Weight (Noun 47): 62,844 pounds (28,506 kg).
Pitch and yaw trim (Noun 48): -1.61° and +1.29°. These are the angles through which the SPS engine should be swivelled to ensure its thrust acts through the spacecraft's centre of mass.
Time of ignition, TIG (Noun 33): 69 hours, 08 minutes, 19.52 seconds.
Change in velocity (Noun 81), fps (m/s): X, -2,984.0 (-909.5); Y, +239.0 (+72.8); Z, +105.3 (+32.1). The change in velocity is resolved into three components expressed relative to the Local Vertical frame of reference.
Spacecraft attitude: Roll, 0°; Pitch, 200°; Yaw, 5°. The desired spacecraft attitude is measured relative to the alignment of the guidance platform which itself has been aligned per the LOI-2 REFSMMAT.
HA, expected apocynthion of resulting orbit (Noun 44): 169.3 nautical miles (313.5 km).
HP, expected pericynthion of resulting orbit (Noun 44): 60.0 nautical miles (111.1 km). The pericynthion will be at the Moon's far side, at roughly the same position that LOI occurred; with the apocynthion occurring over the near side.
Delta-VT: 2,995.4 fps (913.0 m/s). This is the total change in velocity the spacecraft would experience. (It is a vector sum of the three components given above.)
Burn duration or burn time: 4 minutes, 2 seconds.
Delta-VC: 2,978.8 fps. This value is entered into the Delta-V display of the EMS (Entry Monitor System) panel. They will watch this figure descend to zero as the engine burns. If the Guidance and Control System fails to stop the burn, the EMS will do so but it has to be given a low Delta-V figure to take account of the engine's tail-off thrust after shutdown.
Sextant star: Star 01 (Alpheratz, in Andromeda) visible in sextant when shaft and trunnion angles are 68.8° and 25.9° respectively. This is part of an attitude check.
Boresight star: Star Zeta Persei is used for a second attitude check which is made by sighting through the COAS (Crew Optical Alignment Sight).
COAS Pitch Angle: Down 4.8°.
COAS X Position Angle: Left 0.5°.
Other parameters on the PAD sheet are not applicable to this manoeuvre except the details for the backup procedure to align the GDCs.
GDC Align stars: Stars to be used for GDC Align purposes are Sirius and Rigel.
There are two additional comments to this PAD. The SPS propellant tanks are full, so there is no need to perform an ullage burn to settle their contents. The final comment refers to where in the rendezvous window the commander can expect to see the Moon's horizon, and when this occurs. At the edges of this window, lines have been painted to give the seated crewman a good idea of the angle a horizon makes with the spacecraft's X-axis, a helpful check that all is well with the spacecraft's control system. At two minutes to the burn, the Moon's night-time horizon should be at about the 40° line. By the time of ignition, it should be at 27°. However, being an unlit horizon, the crew will only be able to infer its presence by the lack of stars and if the spacecraft interior is lit, it may be difficult to see.
067:23:35 Borman: Roger. LOI-1, SPS/G&N: 62844; minus 1.61, plus 1.29; 069:08:19.52; minus 2984.0, plus 0239.0, plus 0105.3; [Pause.] 000, 200, 005; 0169.3, plus 0060.0; 2995.4, 4:02, 2978.8; 01, zero - 068.8, 25.9; Persei Zeta, down 04.8, left 0.5; Sirius, Rigel, 129, 155, 010; no ullage; horizon, 2 minutes, 40 degrees unlit; ignition, 27 degrees unlit.
067:24:58 Carr: Apollo 8, Houston. Readback is correct. Ready to copy TEI-1. Over.
067:25:05 Borman: Roger. [Pause.]
067:25:14 Carr: Apollo 8, this is Houston. Are you waiting for us to start - before you start your gimbal check? Over.
067:25:23 Borman: We can start the gimbals check right here.
067:25:27 Carr: Roger. You want to copy while you're doing it or stand by on TEI-1?
067:25:35 Borman: Stand by for a minute.
067:25:37 Carr: Roger. Standing by.
Comm break.
067:26:48 Carr: Apollo 8, this is Houston. Shifting command back to Honeysuckle [from Guam]. Over.
067:26:55 Borman: Roger.
Long comm break.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control, Houston at 67 hours, 27 minutes now into the flight of Apollo 8. Apollo 8 now 4,715 nautical miles [8,732 km] away from the Moon. Current velocity reading; 4,933 feet per second, 4,933 feet per second [1,504 m/s]. As we had indicated earlier, the Moon will have traveled about 130 [thousand] nautical miles from the time of lift-off to time of LOI-1. Apollo 8 has now achieved it's proper burn attitude, we've had considerable conversation with the Apollo 8 crew, which we'll pass along now.
Apollo Control, Houston. You heard an update to our LOI-1 maneuver PAD being passed along. This changed only one number and only by one second. The GET, Ground Elapsed Time, of ignition has changed to 69 hours, 19 minutes, 05 seconds - correction - that would be a change of one minute. So at 67 hours, 36 minutes, 05 seconds; this is Apollo Control, Houston.
067:34:46 Carr: Apollo 8, Houston. How did that gimbal drive check go?
067:34:52 Borman: It went fine.
067:34:53 Carr: Roger, Frank. We're ready with the TEI-1 and 2 maneuver PADs. We've also got two state vectors and a target load to uplink and load if you'll configure for it. Over.
067:35:07 Borman: Roger. We're trying to get the High Gain [Antenna] now. We're maneuvering back to PTC attitude.
Having manoeuvred to the correct attitude for the LOI burn, the spacecraft is being manoeuvred back to the attitude to start a PTC roll. This will be adopted for about thirty minutes when Jim will carry out a realignment of the guidance platform for which he will readjust the spacecraft't attitude.
067:35:15 Carr: Roger. [Pause.]
067:35:24 Lovell: Go ahead with your TEI PADs.
067:35:29 Carr: Apollo 8, this is Houston. TEI-1, SPS/G&N; 462 - correction - 46728; minus 0.53, plus 1.21; 071:25:04.73; plus 3774.6, minus 0329.9, plus 0084.4. Copy?
067:36:33 Lovell: We're copying.
067:36:35 Carr: Roger. 179, 346, 357; not applicable, plus 0017.6; 3790.0, 3:36, 3770.5; 42, 127.9, 30.9. Copy?
067:37:26 Lovell: Copying.
067:37:28 Carr: Roger. N/A, N/A, N/A; plus 13.50, minus 165.00; 1305.0, 36389, 122:10:45; Sirius, Rigel, 129, 155, 010; ullage two-jets, 20 seconds, jet Bravo, Delta; horizon window, X-axis on horizon at ignition minus 3 minutes; assumes LOI-1. Over. [Pause.]
Throughout Apollo 8's time in lunar orbit, Mission Control will ensure that the crew have access to enough information to allow them to get home without help from the ground, just in case all communication is lost. It's also useful to have the procedures aboard so time is saved in any emergency. Given as a set of PADs, one for each orbit, each would allow the crew to carry out a TEI burn over the Moon's far side. This first TEI PAD is interpreted as follows:
Purpose: This is an abort PAD to place Apollo 8 on a course for Earth should an emergency arise where they could not talk to Mission Control.
Systems: The burn would be made using the SPS (Service Propulsion System) engine under the control of the Guidance and Navigation system.
CSM Weight (Noun 47): 46,728 pounds (21,195 kg). This PAD quotes the spacecraft weight as being over 7.3 metric tonnes less than for the LOI burn. This represents the mass that Mission Control expect to be expended out of the SPS engine bell during the total burn to enter lunar orbit.
Pitch and yaw trim (Noun 48): -0.53° and +1.21°.
Time of ignition, TIG (Noun 33): 71 hours, 25 minutes, 4.73 seconds.
Change in velocity (Noun 81), fps (m/s): X, +3,774.6 (+1,150.5); Y, -329.9 (-100.6); Z, +84.4 (+25.7). These velocities are expressed with respect to the Local Vertical of the Moon. The large positive X component indicates a largely prograde burn, one made along the same direction as the spacecraft's orbital motion.
Spacecraft attitude: Roll, 179°; Pitch, 346°; Yaw, 357°. The desired spacecraft attitude is measured relative to the alignment of the guidance platform which itself has been aligned per the LOI-2 REFSMMAT.
HA, expected apogee of resulting orbit (Noun 44): Not applicable. If this abort burn were to be made, the spacecraft would be on a trajectory coming from the Moon so any apogee figure would be meaningless.
HP, expected perigee of resulting orbit (Noun 44): +17.6 nautical miles (+32.6 km). The perigee distance is so low, it intersects Earth's atmosphere. In other words, the spacecraft will re-enter.
Delta-VT: 3,790.0 fps (1,155.2 m/s). This is the total change in velocity the spacecraft would experience. (It is a vector sum of the three components given above.)
Burn duration or burn time: 3 minutes, 36 seconds.
Delta-VC: 3,770.5 fps. The crew enter this Delta-V into their EMS display. The EMS can shut down the engine using this data if the G&N system fails to do so. Its value is low to allow for the extra thrust imparted by the engine after shutdown, a quantity allowed for the the G&N software but not by the EMS.
Sextant star: Star 42 (Peacock, or Alpha Pavonis) visible in sextant when shaft and trunnion angles are 127.9° and 30.9° respectively. This is part of an attitude check.
Boresight star: Usually in a PAD, there is a second star given as a second attitude check for the COAS to make. However, in this case, it is not being included, perhaps because the window (and hence the COAS) is facing mostly towards the lunar surface and cannot easily see stars.
The next five parameters all relate to re-entry, during which an important milestone is "Entry Interface," defined as being 400,000 feet (121.92 km) altitude. In this context, a more important milestone is when atmospheric drag on the spacecraft imparts a deceleration of 0.05 g.
Expected splashdown point (Noun 61): 13.5° north, 165° west; in the mid-Pacific.
Range to go at the 0.05 g event: 1,305.0 nautical miles. To set up their EMS (Entry Monitor System) before re-entry, the crew need to know the expected distance the CM would travel from the 0.05 g event to landing. This figure will be decremented by the EMS based on signals from its own accelerometer.
Expected velocity at the 0.05 g event: 36,389 fps. This is another entry for the EMS. It is entered into the unit's Delta-V counter and will be decremented based on signals from its own accelerometer.
GET of 0.05 g event: 122 hours, 10 minutes and 45 seconds GET. This is when it is expected that the EMS will be triggered.
GDC Align stars: Stars to be used for GDC Align purposes are Sirius and Rigel.
A number of remarks are appended to the PAD. Prior to the burn, the crew would perform a ullage burn to settle the contents of the four large propellant tanks in the Service Module. To do this, they would fire two of the four rear-facing RCS jets (jets B and D) for twenty seconds, thereby sending the liquids to the outlet end of the tanks.
Further remarks are that if they are at the correct attitude for this abort burn, then at three minutes to ignition, they should expect the Moon's horizon to line up with the zero degrees marks on the left rendezvous window. Also, the burn data assumes that the crew have already performed the first LOI manoeuvre successfully.
[Download MP3 audio file of PAO announcer recording. Clip courtesy John Stoll, ACR Senior Technician at NASA Johnson.]
This is Apollo Control, Houston; 67 hours, 38 minutes. We've twisted our tongue on that last announcement. The Ground Elapsed Time of ignition should read 69 hours, 8 minutes, 19 seconds - we repeat, it should read 69 hours, 8 minutes, 19 seconds; a change of 1 second. So at 67 hours, 38 minutes, 40 seconds; this is Apollo Control, Houston.
067:38:59 Lovell: Houston, Apollo 8. TEI-1 as follows: SPS/G&N; 46728; minus 0.53, plus 1.21; 071:25:04.73. Copy?
067:39:22 Carr: Roger. Copy.
067:39:26 Lovell: Plus 3774.6, minus 0329.9, plus 0084.4; 179, 346, 357; not applicable, plus 0017.6; 3790.0, 3:36, 3770.5; 42, 127.9, 30.9; not applicable three times; plus 13.50, minus 165.00; 1305.0, 36389, 122:10:45; Sirius, Rigel, 129, 155, 010; ullage, two jets, 20 seconds, quads B and D; horizon window, X-axis on horizon at TIG minus 3, assumes LOI-1.
067:40:36 Carr: Apollo 8, Houston. Roger. Correct. [Long pause.]
067:41:05 Lovell: Standing by for TEI-2, if you have it. [Pause.]
067:41:15 Carr: Apollo 8, Houston. We'll be ready with a TEI-2 in about 1 minute.
067:41:19 Lovell: Roger. [Long pause.]
067:42:10 Carr: Apollo 8, Houston; with a TEI-2 maneuver PAD.
067:42:18 Lovell: Roger. Ready to copy.
067:42:21 Carr: Roger. TEI-2; SPS/G&N; 46728; minus 0.53, plus 1.21. Copy?
067:42:47 Lovell: Roger. Copy.
067:42:49 Carr: Roger. 073:21:30.24; plus 2846.6, minus 0035.0, plus 0240.6; 180, 022, 002; not applicable, plus 0018.8. Copy?
067:43:46 Lovell: Roger. Copy.
067:43:48 Carr: Roger. 2857.0, 2:50, 2840.1; 42, 064.1, 29.6; not applicable three times; plus 09.20, minus 165.00; 1295.3, 36175, 146:32:16. Copy?
067:45:01 Lovell: Copy. Looks like you left out a digit in range to go and latitude.
067:45:09 Carr: Apollo 8, Houston. Request you switch your Omni. It's getting pretty garbled now.
067:45:18 Lovell: Roger. Stand by. [Long pause.]
067:45:30 Lovell: Houston, this is Apollo 8. I copied. I question the latitude and the range to go. It appears that you gave me one too few digits in both cases.
067:45:43 Carr: Roger. I repeat, latitude plus 09.20, minus 165.00; 1295.3, 36175, 146:32:16. Copy?
067:46:20 Lovell: I copied.
067:46:21 Carr: Roger. Your GDC Align is no change; ullage, no change; horizon on the minus 2-degree line at ignition minus 3 minutes. Assumes LOI-1. Over. [Long pause.]
The second TEI PAD is interpreted as follows:
Purpose: At the end of their second orbit around the Moon, the crew are due to make their second LOI burn, one that brings them to a circular orbit. Should an emergency arise where they could not talk to Mission Control, this is an abort PAD that would instead place Apollo 8 on a course for Earth.
Systems: The burn would be made using the SPS (Service Propulsion System) engine under the control of the Guidance and Navigation system.
CSM Weight (Noun 47): 46,728 pounds (21,195 kg).
Pitch and yaw trim (Noun 48): -0.53° and +1.21°.
Time of ignition, TIG (Noun 33): 73 hours, 21 minutes, 30.24 seconds.
Change in velocity (Noun 81), fps (m/s): X, +2,846.6 (+867.6); Y, -35.0 (-10.7); Z, +240.6 (+73.3). These velocities are expressed with respect to the Local Vertical reference.
Spacecraft attitude: Roll, 180°; Pitch, 22°; Yaw, 2°. The desired spacecraft attitude is measured relative to the alignment of the guidance platform which itself has been aligned per the LOI-2 REFSMMAT.
HA, expected apogee of resulting orbit (Noun 44): Not applicable. If this abort burn were to be made, the spacecraft would be on a trajectory coming from the Moon so any apogee figure would be meaningless.
HP, expected perigee of resulting orbit (Noun 44): +18.8 nautical miles (+34.8 km). The perigee distance is so low, it intersects Earth's atmosphere. In other words, the spacecraft will re-enter.
Delta-VT: 2,857.0 fps (870.8 m/s). This is the total change in velocity the spacecraft would experience. (It is a vector sum of the three components given above.)
Burn duration or burn time: 2 minutes, 50 seconds.
Delta-VC: 2,840.1 fps. The crew enter this Delta-V into their EMS display. The EMS can shut down the engine using this data if the G&N system fails to do so. Its value is low to allow for the extra thrust imparted by the engine after shutdown, a quantity allowed for the the G&N software but not by the EMS.
Sextant star: Star 42 (Peacock, or Alpha Pavonis) visible in sextant when shaft and trunnion angles are 64.1° and 29.6° respectively. This is part of an attitude check.
Boresight star: Usually in a PAD, there is a second star given as a second attitude check for the COAS to make. However, in this case, it is not being included. This is likely due to the windows facing the lunar surface near the time of the burn.
The next five parameters all relate to re-entry, during which an important milestone is "Entry Interface," defined as being 400,000 feet (121.92 km) altitude. In this context, a more important milestone is when atmospheric drag on the spacecraft imparts a deceleration of 0.05 g.
Expected splashdown point (Noun 61): 9.2° north, 165° west; in the mid-Pacific.
Range to go at the 0.05 g event: 1,295.3 nautical miles. To set up their EMS (Entry Monitor System) before re-entry, the crew need to know the expected distance the CM would travel from the 0.05 g event to landing. This figure will be decremented by the EMS based on signals from its own accelerometer.
Expected velocity at the 0.05 g event: 36,175 fps. This is another entry for the EMS. It is entered into the unit's Delta-V counter and will be decremented based on signals from its own accelerometer.
GET of 0.05 g event: 146 hours, 32 minutes and 16 seconds GET. This is when it is expected that the EMS will be triggered.
GDC Align stars: Stars to be used for GDC Align purposes are Sirius and Rigel.
Additional notes for the PAD mention that the ullage burn to settle the contents of the propellant tanks requires RCS jets B and D to be fired for twenty seconds. Also, at the correct attitude for the abort burn at three minutes to ignition, they should expect the Moon's horizon to line up with the -2° marks on the left rendezvous window. The PAD data assumes the crew have already performed the first LOI manoeuvre successfully.
It is interesting to compare this PAD with the previous version, TEI-1. Though the ignition time is only around two hours later, Retro Officer Chuck Deiterich has chosen to delay the resulting arrival at Earth by around 24 hours. We can presume that the length of burn required to achieve a landing in the mid-Pacific at TEI-1 was approaching the upper limit of what would be available from the tanks. Therefore, by calculating for a later landing for TEI-2, Retro has used a substantially shorter burn duration for TEI-2, giving the crew a much more leisurely coast home.
067:46:58 Lovell: Roger. TEI-2 maneuver PAD; SPS/G&N; 46728; minus 0.53, plus 1.21; 073:21:30.24; plus 2846.6, minus 0035.0, I did not get the sign, 0240.6 for a Delta-VZ. 180, 022, 002; not applicable, plus 0018.8; 2857.0, 2:50, 2840.1; 42, 064.1, 29.6; not applicable three times; plus 09.20, minus 165.00; 1295.3, 36175, 146:32:16. No change in the GDC Align stars, no change in ullage, horizon on the minus 2-degree line at TIG minus 3, assumes LOI-1.
067:48:28 Carr: Apollo 8, this is Houston. Roger. Correct. I repeat Delta-VZ plus 0240.6. Over.
067:48:42 Lovell: Roger. Plus 0240.6.
067:48:46 Carr: Roger. [Pause.]
067:48:57 Carr: Apollo 8, Houston. If you can go [to program] 00 and Accept, we'll start the Nav loads.
067:49:05 Lovell: Roger. [Pause.]
067:49:12 Anders: Go ahead.
Comm break.
The Nav loads consist of Mission Control placing three sets of data directly into the computer's memory. Two of these are state vectors, sets of numbers that define their velocity and position in space, and therefore their trajectory. There are two slots in the computer for this, the second being intended for a future Lunar Module. The other item being uploaded is the required Delta-V for the LOI-1 burn.
This is Apollo Control, Houston. We're going to cut short here for a moment because very shortly we will have our Go/No-Go decision. Incidentally, this block data that's being passed along is contingency information only - making ground information available to the crew for a Trans-Earth Injection burn at the end of the first or second lunar orbits plus PC plus 2 which translates into pericynthion plus 2 hours; the time of closest approach to the Moon plus 2 hours. This information is entered into the onboard equipment, but is used only if an alternate mission becomes necessary. So, at this time we're going to stand by and continue to monitor the loops here in Mission Control for our Go/No-Go decision.
067:51:20 Carr: Apollo 8, Houston. The CM [state] vector is in; working on the [vector for the] LM [slot] now. Over.
067:51:28 Borman: Roger. [Long pause.]
067:52:17 Carr: Apollo 8, Houston. We'd like a cryo fan cycle when you can. Over.
067:52:24 Borman: Roger. We're starting that now.
067:52:26 Carr: Roger. [Long pause.]
067:53:17 Carr: Apollo 8, Houston. The LM vector is loaded. Target load going in now.
067:53:23 Borman: Roger.
Comm break.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
067:55:20 Carr: Apollo 8, Houston.
067:55:25 Lovell: Go ahead, Houston.
067:55:27 Carr: Apollo 8, Houston. The update is complete. You can have the computer, TLM [Telemetry] to Block. Be advised, the erasable dump checks out okay.
Over an hour ago, Mission Control downloaded the entire 2 kilowords of the computer's erasable memory. They wished to check it in light of a problem Jim had encountered during a platform realignment. It is not surprising that no problems were found. The computer is now operating correctly, with no sign of its earlier problem with driving the sextant to the desired star. When the problem occurred earlier, Jim restarted P52, clearing the fault, but most likely it also cleared any data that could be used for diagnosing the problem.
067:55:41 Lovell: Roger. Thank you. We have the computer; we're in Block.
067:55:45 Carr: Roger. [Pause.]
067:55:50 Carr: Apollo 8, this is Houston. We'd like to make, at this time, a down-voice backup comm check. Set the S-band Aux, Tape to Down-Voice Backup, TLM inputs PCM, Low. Over.
067:56:10 Anders: Roger, Houston. And we'd like to have a check of our DSE on low bit rate for voice.
067:56:19 Carr: Roger. Understand you want the DSE check on low bit rate for voice. [Pause.]
067:56:30 Anders: That's affirmative, and we'll give it - we'll give it about 10 minutes now or about 5 minutes, then you can check it out.
067:56:37 Carr: Roger.
Comm break.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
067:57:55 Lovell: Houston, Apollo 8.
067:57:57 Carr: Apollo 8, Houston. Go.
067:58:01 Lovell: As a matter of interest, we have yet to see the Moon. [Pause.]
067:58:07 Carr: Roger. [Long pause.]
067:58:22 Carr: Apollo 8, Houston. What else are you seeing? [Pause.]
067:58:31 Anders: Nothing. It's like being on the inside of a submarine.
Despite being nearer to the Moon than any human in history, the crew have yet to view their quarry, Jim's sightings through the optics excepted. Their spacecraft has relatively small windows, the three largest of which have fogged up. They spent most of their time during the coast broadside to the Sun and their good windows are gazing only at deep space. On top of that, the Moon has been nearly in line with the Sun for most of the trip to the extent that they are probably in its shadow and will not exit until ten minutes before the LOI burn.
067:58:36 Carr: Roger. [Long pause.]
067:59:17 Borman: Houston, we just ran a Program 21. We show a pericynthion of plus 74.9 (nautical) miles with the state vector you just uploaded.
067:59:24 Carr: Roger. Plus 74.9. [Pause.]
067:59:32 Borman: Roger. [Long pause.]
By running Program 21, for ground track determination, as called for in the Flight Plan, the crew can use a state vector to determine where on the Moon they will fly over, and their altitude. The value of 74.9 nautical miles they are getting is a little higher than the 69-nautical-mile figure they were producing earlier.
067:59:50 Carr: Apollo 8, this is Houston. Reading your down-voice backup loud and clear. Request you keep those switches where they are for the remainder of the pass. Over.
068:00:02 Anders: Roger. And I'm rewinding the tape recorder for a dump - for a DSE voice check.
068:00:10 Carr: Roger, 8.
068:00:15 Anders: It's rewound; are you ready to dump? [Pause.]
068:00:23 Anders: We'd like to go to S-band Aux, Tape, briefly so you can dump the tape while we're on the High Gain. We've only got about 30 seconds worth. [Long pause.]
068:00:44 Carr: Apollo 8, Houston. Roger. We'll do that from the ground. Over.
068:00:54 Anders: Roger. And our switch configuration is Down-voice Backup and Stop. And you've got it?
068:00:59 Carr: Roger. We'll dump it. [Long pause.]
068:01:15 Anders: You won't need to dump more than about a minute's worth.
This is Apollo Control, Houston; 68 hours, 32 seconds. We have conversation going back and forth with the crew now. The Apollo 8 spacecraft at this time 3,125.7 nautical miles [5,788.8 km] away from the Moon. And our velocity; 5,319.6 feet per second [1,621.4 m/s]; and we're standing by at this point for our decision which appears very likely to be a Go for lunar orbit. Standing by.
This is Apollo Control, Houston; continuing to stand by for that decision point at 68 hours, 1 minutes, 49 seconds.
068:01:49 Carr: Apollo 8, Houston. Over. [No answer.]
068:02:03 Carr: Apollo 8, Houston.
068:02:04 Borman: Go Houston. Apollo 8.
068:02:06 Carr: Roger. That pericynthion you read out is for ignition. We read that as 75 (nautical) miles; your true pericynthion is 64 miles at 69:10:35. Over.
The time of ignition for LOI is not precisely at pericynthion.
068:02:25 Borman: Roger. [Long pause.]
068:03:03 Carr: Apollo 8, this is Houston with an addition to your TEI-1 maneuver PAD. Over.
068:03:12 Borman: Stand by a minute. [Long pause.]
068:03:25 Borman: Go ahead.
068:03:27 Carr: Roger. Under remarks, add the following: "requires minus MA procedure". Over. [Pause.]
068:03:43 Borman: Requires minus MA procedure.
068:03:47 Carr: Affirmative, 8. [Long pause.]
068:04:07 Carr: Apollo 8, this is Houston. At 68:04, you're Go for LOI.
Hollywood movies, starting with the Tom Hanks classic Apollo 13, picked up on the drama that appears to emanate from the flight controllers calling in to the Flight Director when a Go/No Go decision is required. In a simple procedure, the Flight Director polls each of the relevant controllers one by one and expects either a Go or a No Go call from them. The decision is simple. If all are Go, then that is passed to the spacecraft. If there is a No Go, the affected controller needs to explain what the problem is and have the system work through it.
068:04:17 Borman: Okay. Apollo 8 is Go. [Pause.]
068:04:22 Carr: Apollo 8, Houston. You're riding the best one we can find around. [Pause.]
068:04:30 Borman: Say again.
068:04:32 Carr: You're riding the best bird we can find. Over.
This is Apollo Control, Houston at 68 hours, 4 minutes, 40 seconds. As you've just heard, we've passed along a Go for the Lunar Orbit Insertion burn with the Service Propulsion System engine. Our flight control team here in Mission Control has examined the data and it looks good. So we have a combined crew/ground decision. We are Go. Repeat - Go for Lunar Orbit Insertion One. At 68 hours, 5 minutes, 10 seconds into the flight, Apollo 8; this is Apollo Control, Houston.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:11:45 Anders: The cryo's have been stirred, Houston.
068:11:49 Carr: Roger, Bill. [Long pause.]
068:12:08 Carr: Apollo 8, Houston. We just saw an MC&W light.
Master Caution and Warning Light, often just referred to as the 'Master Alarm'.
068:12:16 Anders: We just tested the caution and warning.
Bill is making progress with his systems checks.
068:12:18 Carr: Roger.
068:12:22 Anders: That's keeping alert.
068:12:24 Carr: Roger. Clint there is getting white.
This is Apollo Control, Houston at 68 hours, 12 minutes, 12 seconds now into the flight. Apollo 8 draws closer to the Moon. Our current distance away; 2,555.9 nautical miles [4,733.5]. Our velocity building up, now reading 5,527.5 feet per second [1,684.7 m/s]. We've stored some tape so we could pass along that Go-No Go decision to you live, so we'll turn and play back that tape now.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:15:59 Carr: Apollo 8, Houston. We're 42 minutes from LOS, and we caught another caution and warning light.
068:16:09 Borman: That was the High Gain Antenna going out of limits.
068:16:12 Carr: Roger.
Long comm break.
Jim is realigning the platform just now, and to do so he alters the spacecraft's attitude. The articulated joint of the HGA can only take the antenna so far as it attempts to track Earth and, evidently, Jim's manoeuvres have taken it out of range. For this realignment, Jim sights on star 23, Denebola (in Leo) and star 30, Menkent (in Centaurus)
This is Apollo Control, Houston at 68 hours, 21 minutes, 22 seconds now into the flight of Apollo 8. Our spacecraft at this time; 2,100 nautical miles [3,900 km] away from the Moon. Velocity continuing to rise; our current reading of 5,743.8 feet per second [1,750.7 m/s]. We had a brief conversation with the Apollo 8 crew moments or minutes back. And we're going to pass that conversation along now.
This is Apollo Control, Houston. You heard the indication from our Capsule Communicator as to time of Loss of Signal over the backside of the Moon. During this pass over the backside, Apollo 8 will perform its Lunar Orbit Insertion burn number 1 with the Service Propulsion System engine. Following this burn, the spacecraft weight should be some 16,000 pounds [7,300 kg] lighter with the expenditure of propellants. A slight plane change of about 2 degrees is combined into this engine firing. The intent of the plane change is to make Apollo 8 pass over a given heading over the primary Apollo zone, and the desired landing site. To harken back to Gemini, it's an MCC [Mid-Course Correction] combination correction. At 68 hours, 23 minutes, 20 seconds into the flight; this is Apollo Control, Houston.
Gemini was very much the precursor program to Apollo. During its ten flights, NASA tried out all the major operational techniques they would require to fulfil the Moon-bound role of Apollo: EVA, manoeuvring, rendezvous, docking, and so on. Among them was the combination of two manoeuvres into one whereby not only might the shape of an orbit be changed by a burn, its plane might also be altered intentionally by proper aiming of the spacecraft's engines. See our Lunar Orbit Insertion article for more details.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:26:25 Carr: Apollo 8, Houston. Comm check.
068:26:30 Lovell: Read you loud and clear, Houston.
This is Apollo Control, Houston at 68 hours, 28 minutes into the flight now of Apollo 8. We're drawing closer to the Moon with the Apollo 8 spacecraft. Our current reading; 1,773.1 nautical miles [3,283.8 km] away. Velocity going up the steep curve now. Our current reading; 5,945 feet per second [1,812 m/s]. We had a very brief communications check with the Apollo 8 spacecraft. They acknowledged that communications looked fine. We're some 30 minutes now away from our time of Loss of Signal and the time that the Apollo 8 spacecraft goes over the backside of the Moon, out of sight from the ground. The LOI-1 burn by the way, is to be performed retrograde to take energy out so that Apollo 8 can dip into a lunar orbit rather than continue with its free return trajectory. For the burn, the crew will be in a heads down position, giving them a visual reference to the lunar surface. The vehicle should be pitched slightly nose up, perhaps on the order of 8 degrees from the local horizontal. At 68 hours, 29 minutes, 25 seconds into the flight, continuing to monitor; this is Apollo Control, Houston.
The crew are well into the swing of their pre-LOI activities. Frank is flying the spacecraft, setting it up for the burn. He operates the computer, going through the procedures associated with P30 and P40 that will allow the computer to control the burn. He also puts the EMS in a mode where it will provide backup control of the SPS engine. Once Jim is finished realigning the guidance platform, Frank will manoeuvre the CSM to the proper attitude for the burn.
With the platform realignment out of the way and the spacecraft manoeuvred to the burn attitude, Jim aims the sextant to the angles in the PAD. He should then find himself looking at Alpheratz, the brightest star in the constellation of Andromeda and one corner of the Square of Pegasus. He then returns to his couch ready to monitor the RCS system.
Bill has responsibility for the spacecraft's systems and is carrying out a long series of checks per the Flight Plan. He uses the Systems section of his checklist and, as we saw earlier, has already done checks of the Caution and Warning lights at the top of the Main Display Console. He also makes checks of the RCS circuits of both the Command and the Service Modules, the SPS, electrical power and environmental control systems.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:30:37 Anders: Houston, Apollo 8. Over.
068:30:40 Carr: Apollo 8, Houston. Go.
068:30:45 Anders: Roger. We're ready to activate the primary water boiler.
As more systems come online for the LOI burn, the amount of heat being generated by the electronics rises. Once the radiators on the side of the Service Module cannot lose sufficient heat from the system, an evaporator is brought into the circuit to deal with the excess. If the temperature of the coolant coming from the radiators is still too warm, extra waste water is fed to the evaporator to make it cool more effectively.
068:30:49 Carr: Roger. Copy.
068:30:53 Anders: We got a Go [for the boiler]?
068:30:57 Carr: Roger. Go.
068:31:01 Anders: Okay. Steam pressure going to Auto; H2 flow going to Auto. [Long pause.]
068:31:49 Carr: Apollo 8, Houston. We're on low bit rate. We won't see your steam pressure; your Rad Out is 33. Over.
068:32:01 Anders: Roger. We're below the boiling limit, and steam pressure is steady at 0.15.
This is Apollo Control, Houston at 68 hours, 33 minutes, 8 seconds now into the flight of Apollo 8. Apollo 8 now 1,517 nautical miles [2,809 km] away from the Moon. Current velocity reading 6,120.2 feet per second [1,865.4 m/s] and accelerating. The Apollo 8 is currently going through a series of systems checks. We've had some conversations, Jerry Carr Capsule Communicator with Bill Anders aboard the spacecraft, and we'll pick those up for you now.
068:33:21 Carr: Apollo 8, this is Houston. We've got our lunar map up and ready to go.
068:33:29 Borman: Roger.
Long comm break.
Jerry Carr is referring to the large display screen at the front of the Mission Operations Control Room. Throughout most of the Gemini program and those Apollo flights that came before this one, Mission Control was dominated by a large map of Earth over which a representation of the spacecraft was animated. During the translunar coast, the display showed the Earth-Moon system. Now a buzz is being generated by the fact that Mission Control is showing a map of another world over which humans are about to fly for the first time.
This is Apollo Control, Houston. You heard that last report. Our lunar map - lunar display is up here in Mission Control Center and we are ready to go at 68 hours, 34 minutes, 48 seconds into the flight of Apollo 8; this is Apollo Control, Houston.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:37:38 Anders: Houston, Apollo 8. Over.
068:37:40 Carr: Apollo 8, Houston. Go.
068:37:45 Anders: Roger. We're showing a fuel pressure of 167, an Ox(idizer pressure) of 163. Wondering, do you think there's a possibility of us having a transient Caution/Warning trip on fuel/Ox pressure at the beginning of the burn that would correct itself nominally as we had a chance to pressurize? Over.
Bill is worried that they might get a Master Alarm indicating an imbalance between the SPS fuel and oxidizer pressures. This pressure difference is expected to sort itself out once the engine begins firing, and the helium system begins active management of the tank pressures.
068:38:12 Carr: Roger. Understand; will check. Stand by.
068:38:20 Anders: Roger. [Long pause.]
068:38:43 Carr: Apollo 8, Houston.
068:38:49 Lovell: Go ahead.
068:38:51 Carr: Apollo 8, this is Houston. We've been reading fuel 173, Ox 167; holding steady for a long period of time. We expect no Caution and Warning trip. Over. [Pause.]
This is Apollo Control, Houston at 68 hours, 40 minutes, 54 seconds now into the flight. Apollo 8 now 1,128 nautical miles [2,089] away from the Moon. Our current velocity reading; 6,467 feet per second [1,971 m/s]. We've had a brief conversation. Jerry Carr has talked to Bill Anders aboard the Apollo 8 spacecraft regarding Service Propulsion System tank pressures, and we're going to play that conversation now.
Apollo Control, Houston. Meanwhile here in Mission Control Center, our LOS clock, Loss of Signal clock, continues to count down. We now read, Mark, 15 minutes, 26 seconds until that time that the Apollo 8 spacecraft will pass out of communications range over the backside of the Moon. And at 68 hours, 42 minutes, 50 seconds into the flight; this is Apollo Control, Houston,
This is Apollo Control, Houston at 68 hours, 47 minutes, 12 seconds now into the flight of Apollo 8. Apollo 8 now 825 nautical miles [1,528 km] away from the Moon. Our velocity continuing its rise at an increasing pace now. We read 6,836 feet per second [2,084 m/s]. And at this time we're 10 minutes, 29 seconds away from time of Loss of Signal. We've had no further communications with the crew who are no doubt quite busy as of this moment in preparation for their first Lunar Orbit Insertion burn. And at 68 hours, 48 minutes, continuing to monitor; this is Apollo Control, Houston.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:48:30 Carr: Apollo 8, Houston. Nine minutes, 30 seconds from LOS.
Apollo Control, Houston; 68 hours, 49 minutes. Apollo 8 now 730.7 nautical miles away. Velocity; 6,957 feet per second. We've had conversation with the Apollo 8 crew and we're going to pick that up now.
This is Apollo Control, Houston. As you heard on that mark, they were counting down for time of ignition. Meanwhile at Mission Control Center, our time away from LOS now reading 7 minutes, 50 seconds. And at 68 hours, 50 minutes; this is Apollo Control, Houston.
This is Apollo Control, Houston at 68 hours, 52 minutes into the flight of Apollo 8. Apollo 8 now 582 nautical miles [1,078 km] away. Velocity reading; 7,191 feet per second [2,192 m/s]. We're some 5 minutes, 30 seconds away from LOS at this time. At this time Glynn Lunney has gone around the room taking a status check with his flight control team. We look Go. We continue to stand by, and this is Apollo Control, Houston.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:53:06 Carr: Apollo 8, Houston. Five minutes LOS, all systems Go. Over.
068:53:13 Borman: Thank you. Houston, Apollo 8.
068:53:17 Carr: Roger, Frank. The custard's in the oven at 350. Over. [Pause.]
068:53:30 Borman: No comprendo. [Pause.]
068:53:38 Borman: Roger.
Comm break.
An explanation for Jerry Carr's rather cryptic remark comes from Genesis: The Story of Apollo 8 by Robert Zimmerman. In his account of the flight he explains how the remark was a message from Frank's wife, Susan Borman, to her husband. It was meant to reflect her understanding of their relationship; that while he flew the jets, she would cook the custard. It was meant as a message to reassure him that she was the supporting wife, standing by him and looking after the home while he was flying his exotic machines.
Apollo Control, Houston; 68 hours, 54 minutes now into the flight. Our Apollo 8 spacecraft now 529 nautical miles [980 km] away. Velocity reading 7,286 feet per second [2,221 m/s]. Jerry Carr has spoken with the crew and we're going to pick up that conversation now.
This is Apollo Control, Houston. We're now some 3 minutes, 35 seconds away from LOS and standing by.
Apollo Control, Houston; 2 minutes, 50 seconds away from time of LOS now. Our distance away from the Moon; 460 nautical miles [852 km]. Velocity, 7,417 feet per second [2,261 m/s]. Here in Mission Control, we're standing by. There's certainly a great deal of anxiety at this moment as in the next 2½ minutes we will not talk with the crew for some period of time. We acquire at 36 minutes. So at 68 hours, 55 minutes continuing to monitor this is Apollo Control.
[Download MP3 audio file. Clip courtesy Bernard Scrivener, Honeysuckle Creek Tracking Station.]
068:56:06 Carr: Apollo 8, Houston. Two minutes until LOS.
Two minutes away now from LOS. 418 nautical miles [774 km] now away from the Moon. Our velocity continuing to build up; 7,518 feet per second [2,291 m/s]; continuing to climb. One minute, 30 seconds away now from Loss of Signal. Our distance away from the Moon now 401 nautical miles [743 km]. Velocity reading 7,535 [fps, 2,297 m/s] as we continue with this flight of Apollo 8.
068:57:06 Carr: Apollo 8, Houston. One minute to LOS. All systems Go.
068:57:12 Anders: Roger. Going to Command Reset, tape recorder Forward, low bit rate.
Once the onboard recorder is started, the crew's voices will be recorded, giving us a record of what goes on During LOI, even though the spacecraft is out of touch with Earth.
We have a correction to that voice from the spacecraft. That was Bill Anders.
The technical transcript has Anders and Lovell's utterances as a single line. On listening to it, however, it does indeed sound like Jim says the last phrase.
068:57:28 Lovell (onboard): What's this...
068:57:29 Borman (onboard): What's that LOS time, Bill?
068:57:32 Anders (onboard): 58:58 - 68:58.
068:57:35 Borman (onboard): See if we lose the signal then.
068:57:37 Anders (onboard): Okay.
068:57:38 Borman (onboard): What was the seconds? Jim?
068:57:42 Lovell (onboard): I didn't bother with it; wasn't it something like 58:02?
068:57:54 Carr: Apollo 8, 10 seconds to go [to LOS]. You're Go all the way.
We've had loss of a signal with Apollo 8 at 68 hours, 58 minutes, 45 seconds. We will watch with continuing interest the AOS clock here in Mission Control.
This is Apollo Control, Houston; 69 hours now into the flight of Apollo 8. We're going to pick up that transmission when Jerry Carr advised that we were LOS.