During Apollo lunar missions, had the command module pilot have died while the other two astronauts were on the Moon, or had only one of the two lunar walkers died, did NASA have a procedure for such a possibility and if so, what was it?

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    $\begingroup$ The incapacitated CMP scenario is the interesting one. There's an article here about it, validity unknown, so posting as comment. spaceflightblunders.wordpress.com/2017/04/07/… $\endgroup$ Commented Jul 18, 2020 at 14:10
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    $\begingroup$ @OrganicMarble: A very interesting article! $\endgroup$
    – Fred
    Commented Jul 18, 2020 at 14:27
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    $\begingroup$ There does seem to have been an official memo "Operations Groundrule for Disabled CSM Astronaut" maybe someone can turn it up. $\endgroup$ Commented Jul 18, 2020 at 14:49
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    $\begingroup$ @OrganicMarble: The quotations in my answer are from The Apollo Spacecraft: A Chronology, which in turn cite the very memo you reference. $\endgroup$
    – DrSheldon
    Commented Jul 18, 2020 at 16:23
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    $\begingroup$ @Fattie: a grim question indeed, but something that needs to be considered in space missions. NASA wasn't counting on 3 astronauts being killed in fire in 1967, nor on tank exploding on Apollo 13, or the two Shuttle catastrophes. As for the written but never used speech, it formed the basis of my answer to this question $\endgroup$
    – Fred
    Commented Jul 19, 2020 at 9:46

1 Answer 1


Yes, it was considered. The Command Module Pilot didn't have to die; the mere disability of the CMP was an issue.

The earliest consideration of such a scenario was reported on August 25, 1964. The two major concerns were to stabilize the CSM's attitude and to turn on the docking radar transponder. The proposed solution was to allow ground control of both of these systems:

At a Contractor Coordination Meeting on June 9-10, the point had been made that there existed a single- point failure that would preclude the crew's safe return - a disabled crewman in the CM during LEM operations. MSC demanded unequivocally that, even under these circumstances, the two crewmen in the LEM must be able to complete the mission. Therefore, the CSM must be designed for such a contingency; and to limit hardware impact, this must be done by using onboard equipment as much as possible.

Accordingly William F. Rector III, the LEM Project Officer in ASPO, advised Grumman of two operational requirements:

  • The radar transponder in the CSM must be turned on before the LEM's ascent from the moon and must be pointed toward the LEM during ascent and rendezvous.
  • The CSM's attitude had to be stabilized during this phase of the mission.

The two prime contractors, Rector said, should decide on some means of controlling remotely the CSM's transponder and its stabilization and control system. The contractors should, however, use the simplest and most reliable arrangement. To initiate these two functions, the CSM would receive commands from the ground. Finally, Rector informed Grumman of a new ground rule on CSM communications: continuous communications, both telemetry and voice, must be maintained whenever the spacecraft was in view of the earth.

On October 15, NASA reversed their decision, assuming that the CMP would turn these two systems on manually before becoming disabled:

Remote operation of the CSM's rendezvous radar transponder and its stabilization and control system (SCS) was not necessary, ASPO told North American. Should the CSM pilot be incapacitated, it was assumed that he could perform several tasks before becoming totally disabled, including turning on the transponder and the SCS. No maneuvers by the CSM would be required during this period. However, the vehicle would have to be stabilized during LEM ascent, rendezvous, and docking.

The next day, the lunar module contractor suggested a compromise. The CMP would stabilize the CSM attitude and turn on the transponder before the lunar module attempted an ascent:

In another letter on October 16, the Project Office notified Grumman that no requirement existed for remote operation of either the rendezvous radar transponder or the stabilization and control system. The letter added, however, that the possibility of an incapacitated CSM astronaut must be considered and that for design purposes Grumman should assume that the astronaut would perform certain functions prior to becoming completely disabled. These functions could include turning on the transponder and the SCS. No CSM maneuvers would be required during the period in which the CSM astronaut was disabled but the CSM must remain stabilized during LEM ascent coast and rendezvous and docking phases.

Although the usual plan was to have the CSM be the active spacecraft during rendezvous, the guidance computer in the LM was also given rendezvous software, and the LM crew was given training for that contingency.

Then there was the issue of physically getting into the command module. The docking tunnel hatch could not be opened from the LM side. Thus, a spacewalk to the CM side hatch would be necessary. This was practiced by Rusty Schweickart on Apollo 9. They would then use tool B to crank open the hatch.

As for the death of one of the lunar module astronauts, the LM could be piloted by only one crewman. The body of the dead astronaut would be returned to Earth, if possible.

During normal flight, both astronauts were assigned tasks. However, there were three automatic modes for returning the LM back to orbit, to be rescued by the CSM. Each mode could be initiated by either astronaut. (Source: Apollo Operations Handbook: Lunar Module volume II)

  • During descent to landing on the moon, program 70 could be executed on the Lunar Guidance Computer (contingency procedure #
  • From the surface of the moon or during ascent, program 71 could be executed (contingency procedure #
  • The Abort Guidance System was a separate system which could also automatically put the LM into a rescue orbit, by pushing either the ABORT or ABORT STAGE pushbuttons.

If possible, the body would be returned for several reasons:

  • Re-entry through Earth's atmosphere critically depends upon the CM having its center-of-mass in the correct location. A missing crewman's body shifts the center-of-mass, which then affects the angle at which the CM impacts the atmosphere, which can result in overheating of the wrong parts of the heat shield. This is why "ballast" was brought back during Apollo 13, to compensate for the missing moon rocks.
  • A body is needed for an autopsy. The results could help improve the safety of future astronauts.
  • The body also allows the family to have a proper funeral.
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    $\begingroup$ Probably the worst scenario would be for the CMP to be alive, but disabled and not in his spacesuit. There would be no way for the other astronauts to get to the CMP without depressurizing the CM, thus killing the CMP. It's an obvious choice between three astronauts stranded in lunar orbit, versus two getting home alive. Nonetheless, I can only imagine the regret that the astronaut who would have to depressurize the CM would have. $\endgroup$
    – DrSheldon
    Commented Jul 18, 2020 at 15:58
  • $\begingroup$ I concur with @OrganicMarble, great answer for the CMP part. I was also wondering had the CMP died, would the body return to Earth with the other two astronauts or would it be given a "sea type burial" in space and the body ejected into the cosmos? $\endgroup$
    – Fred
    Commented Jul 18, 2020 at 21:06
  • $\begingroup$ @Fred A close investigation of the cause of death would be desired. However, the situation for the other two during the return might be quite awkward $\endgroup$ Commented Jul 18, 2020 at 22:18
  • $\begingroup$ @HagenvonEitzen: I agree and maybe not just awkward but difficult & uncomfortable too. $\endgroup$
    – Fred
    Commented Jul 18, 2020 at 23:22
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    $\begingroup$ Did they have body bags? $\endgroup$ Commented Jul 19, 2020 at 11:06

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