The Moonwalkers Who Could Have Been

In the three and a half years between July, 1969 and December, 1972, twelve people walked on the moon. That fact is now well known. What is less well know is that there were fourteen others that could equally well have done so. Most people know the story of Apollo 13, which was sent to the moon with the intention of landing. But that accounts only for two of the other possible moonwalkers. Who were the other twelve, and what basis do we have for saying that they were possible moonwalkers? That is the purpose of this page.

People who said no to a possible moonwalk

Frank Borman
According to both Slayton and Borman, Borman elected to retire rather than retrain on the LM in 7 months for Apollo 11 (at the time, Borman had no LLRV/LLTV experience). He informed Slayton of his intentions before flying Apollo 8, so he was not actually offered the Apollo 11 mission, but Slayton says that he would have considered sending the Apollo 8 crew on Apollo 11 if Borman had been willing. Borman further says that he was not interested in flying any mission after Apollo 11 because his primary motivation was flight testing rather than science. Borman never flew in space again after Apollo 8, his second mission.
Jim McDivitt
According to Slayton, McDivitt was offered the LMP seat on Apollo 14 with Sheppard commanding the mission. Slayton says that McDivitt declined the offer, at least in part because he did not wish to accept the mission if not in command. McDivitt, in his NASA oral history, says that he could have had command of Apollo 13 if he had wanted it. The Apollo 13 and 14 crews were swapped prior to their official assignment, so it is not clear which of the two missions McDivitt was referring to. Whichever account is correct, it is clear that McDivitt could have had a prime crew assignment on a lunar landing mission if he had wanted it. At one point, Slayton also considered assigning the entire Apollo 9 crew (which McDivitt commanded) to Apollo 12, but he later decided against that when Borman declined to consider taking the Apollo 11 mission. McDivitt never flew in space again after Apollo 9, his second mission.
Mike Collins
According to both Slayton and Collins, Collins was offered command of the Apollo 14 backup crew, which would have led to command of Apollo 17. He declined that opportunity, and never flew in space again after Apollo 11, his second mission.

Others Who Could Have Had a Moonwalk

These people lost a good chance at a moonwalk due to some event that was beyond their control that could reasonably have come out the other way:
Jim Lovell
Commanded Apollo 13. Failed to land due to oxygen tank explosion. Never flew in space again after Apollo 13, his fourth mission.
Fred Haise
LMP on Apollo 13. Failed to land due to oxygen tank explosion. Commanded the Apollo 16 backup crew, and in line for command of Apollo 19 prior to its cancellation due to budget reductions. Haise commanded a Shuttle Approach and Landing Test crew, but he never flew in space again after Apollo 13, his first mission.
Joe Engle
According to multiple sources, Engle was nominated as Apollo 17 LMP by Slayton and disapproved by NASA HQ in order to provide an LMP slot for Schmitt. This would not have been necessary if Schmitt (at the time, the Apollo 15 backup crew LMP) had replaced Irwin to fly as LMP on the Apollo 15 crew, an option had been considered (but rejected) at the time as a way of getting Schmitt to the moon, for which there was considerable political pressure. Earlier, while Engle was serving as backup LMP for Apollo 14, Slayton had raised the possibility of replacing Mitchell with Engle as LMP on Apollo 14 as a threat to get Mitchell to agree to serve on the backup crew for Apollo 16 after his flight. Mitchell then agreed to do so, so the threat was not carried out. There are therefore three decisions, any one of which would have resulted in Engle going to the moon had they come out differently. Engle Eventually commanded two shuttle missions.
Dick Gordon
Commanded the Apollo 15 backup crew, and therefore in line for command of Apollo 18 prior to its cancellation due to budget reductions. Gordon never flew in space again after Apollo 12, his second mission.
Jerry Carr
According to Slayton, internally selected as LMP for Apollo 16 backup crew, which would have put him in line for LMP on Apollo 19. Moved to the Skylab program upon cancellation of Apollo 19 due to budget reductions, which occurred prior to the announcement of the Apollo 16 backup crew. Carr later commanded Skylab 4, his only mission.
Tom Stafford
According to multiple sources, some consideration was given to assigning the first lunar landing to Apollo 10, which Stafford commanded. It was ultimately decided that Apollo 10 could land no more than one month sooner than Apollo 11 could (because Apollo 11's lighter LM was required, and because the Apollo 10 crew would have needed some additional training), and that the additional tracking experience from a second lunar mission would be useful when planning the first landing. Apollo 10 therefore flew a lunar orbital mission as originally planned. Stafford later flew again as CDR of the ASTP mission, his fourth mission.
Bill Anders
Anders could have landed on the moon if Borman's crew had been assigned to Apollo 11 upon their return from the Apollo 8 mission since he was the LMP on that crew. Anders served as the backup CMP for Apollo 11, and was offered the CMP position on Apollo 13. This could have led to command of Apollo 19 (had that mission not been cancelled), but Anders (correctly) believed that the program was unlikely to last that long. He never flew in space again after Apollo 8, his only mission.
Rusty Schweickart
According to Slayton, Schweickart would have been considered as backup LMP for Apollo 12, which would have put him in line to fly as LMP on Apollo 15. Because of a serious incident of motion sickness during Apollo 9, this did not seem to Slayton to be a viable option. Little was known about Space Adaptation Syndrome at that time; it is now known that about one third of all astronauts will experience similar effects during their first few days in space.

People who would likely have walked on the moon if they had lived:

Gus Grissom
Commanded Apollo 1, and according to Slayton in line for command of the first lunar landing mission. Died in the Apollo 1 fire after flying two missions (one Mercury and one Gemini).
C.C. Williams
Backup LMP on Apollo 9, in line to fly as LMP on Apollo 12. Died in a T-38 crash before Apollo 9 flew. Never flew in space.
Charlie Basset
According to Slayton, would have been CMP on Apollo 8. This was the slot filled by Lovell, who flew as CDR on Apollo 13 as a result of the normal rotation of CMP's from early Apollo missions to a later landing mission as CDR. Died in a T-38 crash while assigned to the Gemini 9 crew. Never flew in space.

Some Others

Beyond those fourteen, there were also a number of other people with some nontrivial chance of having walked on the moon if some things had been different. Here are some of the more obvious cases in that category:
Gordon Cooper
According to Cooper, offered CDR on the Apollo 13 backup crew, which may have led to CDR on Apollo 16. Declined because he believed that office politics would result in substitution of someone else when the Apollo 16 crew was named after Apollo 13 flew. Cooper was not assigned to command Apollo 13 after having commanded the backup crew for Apollo 10, and Slayton says that he had no further plans for Cooper after Gemini 5. Both of those facts suggest that Cooper's perception may have been correct.
Ted Freeman
Freeman was selected with the 1963 group and (according to the Astronaut Hall of Fame timeline) designated in 1964 by Slayton as one of six LMP's for an early mission. 7 of the 11 members of the 1963 group that survived did land on the moon or were clearly in line to do so, so it seems reasonable to expect Freeman to have been offered a similar opportunity if he had lived. Died in a T-38 crash before assignment to a crew.
John Bull
According to Slayton, Bull would have been one of his early picks from the 1966 astronaut class as an LMP. Bull was trained as an LM specialist and assigned to the support crew for the second flight that was planned to carry a lunar module (which later became Apollo 8), but he was medically disqualified prior to assignment to a backup crew and never flew in space.
Ed White
White was assigned as CMP on Apollo 1, but there were no specific plans at the time of the fire for a follow-on mission for him. He was a member of the 1962 astronaut class, for which all members that survived were possible moonwalkers (and for which 4 were actual moonwalkers). It therefore seems unlikely that White would not have been offered a moonwalk at some point. He died in the Apollo 1 fire after only a single Gemini mission.
Ken Mattingly
Originally assigned as CMP on Apollo 13, making him first CMP from his 1966 astronaut class to be assigned to a mission and the first person that would have flown solo on an Apollo mission without prior rendezvous experience if Apollo 13 been had flown as planned. Normal rotation would have made him eligible to command the Apollo 16 backup crew (which Fred Haise from Apollo 13 actually did), which would have put Mattingly in line for command of Apollo 19 (had it not been cancelled for budget reasons). This set of possibilities unraveled early when Mattingly was removed from the Apollo 13 mission because he had no documented immunity to measles, to which he might have been exposed. He flew as CMP on Apollo 16 and commanded two Shuttle Missions.
Donn Eisele
According to the Astronaut Hall of Fame timeline, at the time of the Apollo 1 fire, Slayton planned to assign Eisele as LMP for the F mission (which became Apollo 10) with Grissom as commander. Had Grissom commanded the first lunar landing, Eisele would therefore have been a logical choice as LMP. Eisele flew on Apollo 7, but he was not seriously considered for later flights. According to Stafford, Eisele was asked to leave after serving as CMP on the Apollo 10 backup crew because of declining performance. Apollo 7 was his only mission.

Reference Data

Members of the 1963 Astronaut Group ("The Fourteen") Designated at Some Point as Lunar Module Pilots

Members of the 1966 Astronaut Group ("The Original 19") Trained as Lunar Module Specialists

Last modified: Sat Jun 5 13:01:14 2004
Doug Oard