Apollo 14

This is Apollo Control. We've had loss of signal. Apollo 14 nearing the end of the 12 lunar revolution. Earlier in this front side pass, one of the first items was the soft undocking which occured in actual time at 104:28:01. The undocking was done in a radial direction to minimize the perdibations to the spacecraft trajectory caused by the mechanical unlinking of the two spacecrafts. Everyone was quite happy with the way the undocking took place in view of the earlier apparent problems with the probe and drogue during translunar coast. Shortly after the undocking the Lunar Module crew of Mitchell and Shephard ran through the descent propulsion system throttle checks starting at 104:40. They photographed and observed the landing site Fra Mauor and midway through this pass and Mitchell made the comment that it quote, "looks just like the map". Toward the end of this revolution, Stu Roosa was given a go for the circulization maneuver that he will make in some 24 minutes from now, the ignition clock counting down to the CSM burn which will put the command service module back into a near circular lunar orbit. That maneuver is now scheduled for a Ground Elapsed Time of 105 hour 51 minutes 48 seconds. The velocity change will be posigrade 76.2 feet per second which will raise the command service module pericynthion to 55.5 nautical miles, apocynthion as 63.3. This is biased somewhat so that at the time of rendezvous, when the Lunar Module ascends from the surface to rendezvous with the command and service module the orbit will have modified itself to near circular at 60 nautical miles. We show acquisition of signal at the start of the 13th lunar revolution in some 44 minutes now. Count down to the CSM circularization burn now 23 minutes 23 seconds. At 105 hours 28 minutes Ground Elapsed Time, this is Apollo Control.

This is Apollo Control, 106 hours 11 minutes Ground Elapsed Time. Some 52 seconds away from acquisition in this 13th lunar revolution of Apollo 14. At this time the Command Module should have circularized to about 16 nautical, leaving the Lunar Module in the 60 by 8 eliptical orbit. Upcoming on this revolution is pressurization of the descent propulsion system. Our checkout of the landing radar on the Lunar Module. Checkout of the landing point designator which is a grid device on the Commander's window which allows him to sight in on the landing point using angles given to him by the Lunar Module computer. Let's pick up air to ground now.

This is Apollo Control. By way of explanation of some of the discussion between the ground and the crew of Apollo 14 regarding the strange signal in the Lunar Module computer. It seems that during revolution 12, front side pass, a spurious bit in the LM guidance computer registers were telemetered to the Mission Control Center here and they showed that an abort command was issued while the computer was in program 52, which is inertial measurement unit realignment program. During program 63, 64 and 66 which are concerned with the descent and power descent and landing programs, such an electronic spook would certainly cause an unintentional abort. One cause of this spurious bit in the software program could be contamination in the abort switch itself. Meanwhile, Massachusetts Institute of Technology, prime contractor for the Apollo guidance system, has evolved a procedure for inhibiting the abort command in the primary guidance and navigation system, which in effect would tell the computer to ignore abort - or abort stage commands. Early in this revolution, revolution 13, in the front side pass, the abort command bit again showed up in the DSKY or display keyboard readouts, both onboard and here in Mission Control, but they disappeared when the crew tapped the abort switch. Standing by on air/ground for further conversation on lunar orbit 13. This is Apollo Control at 106 hours 45 minutes Ground Elapsed Time.

This is Apollo Control, we've now had loss of signal with the Command Module Kitty Hawk...

Spacecraft communicator Gordon Fullerton attempting to continue talking to the spacecraft apparently did not hear network sing out we've had lost of signal. During the latter portion of that front side pass the Lunar Module crew will have passed up to them the procedure whereby they can bypass the spurious bit in the Lunar Module computer, which could and would cause an abort during power descent. Essentially, what it amounts to is considerable amount of stroking of the keyset of the DSKY to enter numbers into the LM guidance computer. Verb 25 Noun 07 etc. which in... would disable program 70 which is descent propulsion system abort and program 71 which is ascent propulsion system abort. If we do this after ignition on a normal P63 your program 63 but before they throttled up beyond 10 percent which occurs about 20 seconds - 26 seconds after ignition. Having locked out program 70 and 71, abort could not be made on the primary guidance system, but on the secondary guidance system in the LM the abort guidance system as it's called AGS. We're still some 40 minutes 56 seconds away from acquisition of the Lunar Module again on rev 14. The last rev before landing. And, 44 minutes 11 seconds away from acquisition of Command Module Kitty Hawk. At 107 hours 27 minutes Ground Elapsed Time this is Apollo Control.

This is Apollo Control 107 hours 45 minutes Ground Elapsed Time. Apollo 14 spacecraft now separated into Lunar Module, Antares, and Command Module, Kitty Hawk. Now behind the Moon nearing the start of the 14 revolution. There's about 21 minutes until the Lunar Module appears from behind the Moon and is picked up by the ground tracking stations and 25 minutes until the Command Module is again picked up. To recapitulate the current situation with the LM guidance computer, the problem first cropped up during revolution 12 on the front side pass, when a spurious bit or number or digit cropped up in a readout on the ground, telemetered to ground from the spacecraft in the LM guidance computer. This spurious bit or electronic spook showed that an abort command was issued while the computer was in program 52. Which, in program 52, is actually an inertial measurement unit realinement. Had it been during an engine maneuver where the engines had been ignited, either say in power descent or another phase of the mission involving thrusting, the abort command would have indeed affected the engines. However, in the platform alignment, such as P52, it did nothing other than just show up on the registers on the displays here in mission control. But also on the DSKY or the display keyboard in the spacecraft cabin. During program 63 and 64 and 66, the three programs which are used for the power descent and landing on the lunar surface, such an electronic spook would cause an unintentional abort which is highly undesireable in this mission. Contamination in the abort switch itself is a suspected cause of the indication. Massachusetts Institute of Technology who is prime contractor for the Apollo Guidance System, has evolved a procedure for inhibiting the abort command in the primary guidance and navigation systems which in effect would tell the computer to ignore abort or abort stage commands. Essentially, this procedure as submitted by MIT is a series of numbers which would be entered into the computer by the Lunar Module Pilot after power descent ignition of the descent propulsion engine. He would have all these numbers to enter into the computer prior to the time of throttle up beyond 10 percent of myout power, which is about 26 seconds. The numbers would in effect disable the abort program which is program 70 on the case of descent propulsion engine and program 71 on the ascent propulsion. It would lock out these two programs , however, an abort further on down into the descent phase could only be made on the abort guidance system and not on the primary guidance system. Twice in the just completed revolution 13 front side pass, the abort command bit or electronic spook again showed up on the DSKY onboard and again here in the control center where DSKY readouts are available from telemetered displays. Again, the abort command bit disappeared when the crew tapped the abort switch. That, in affect, summarizes the current situation with the mysterious abort signal cropping up in the Lunar Module computer. We're now 17 minutes 3 seconds away from acquisition of Antares, 20 minutes 25 seconds away from acquisition of Kitty Hawk as they come around on their 14 lunar revolution. The network is conducting test through various tracking stations before we have acquisition. And at 107 hours 50 minutes Ground Elapsed Time, this is Apollo Control.

This is Apollo Control 108 hours 6 minutes Ground Elapsed Time. Coming up on the start of REV 14 in the mission of Apollo 14. We've got about 46 minutes, as you were, 42 seconds until acquisition of signal with Lunar Module Antares and about 4 minutes even until Command Module Kitty Hawk comes over the hill. All the displays here in the front of Mission Control have been changed from the lunar orbit tracking chart, to the XY plotter type of presentations for the descent phase. Ignition for the powered descent phase of Lunar Module descent to the surface will be at 108 hours 42 minutes 27.5 seconds. We have had acquisition of the Lunar Module. We'll standby for any conversation as they come over the hill. Ignition countdown clock now showing 34 minutes 44 seconds to PDI ignition.