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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Canceled Apollo missions | 2/4 | https://en.wikipedia.org/wiki/Canceled_Apollo_missions | reference | science, encyclopedia | 2026-05-05T12:33:17.921323+00:00 | kb-cron |
In September 1967, NASA created a list of remaining mission types necessary to achieve the first crewed lunar landing, each designated by a letter A through G, where G would be the first crewed landing. This list was later extended through letter J to cover follow-on lunar missions. Two uncrewed Saturn V test launches (A missions) were flown as Apollo 4 and Apollo 6. A third test was planned but canceled as unnecessary. The first development Lunar Module, LM-1 was flown uncrewed (B mission) as Apollo 5. A second uncrewed test was planned using LM-2 but was canceled as unnecessary. LM-2 was retrofitted to look like a production LM which would land men on the Moon and was donated to the Smithsonian National Air and Space Museum, where it is currently on display as a simulation of the Apollo 11 first landing. Schirra's crew would fly the C mission, first crewed CSM (Block II CSM-101, retrofitted with the cabin safety improvements) as Apollo 7 in October 1968. McDivitt's crew and mission were kept as the first crewed development LM flight (D mission); this was planned to be Apollo 8 in December 1968, now using a single Saturn V launch vehicle instead of two separate Saturn IB launches. The E mission was planned as an elliptical medium Earth orbit test of the operational LM with the CSM in a simulated lunar mission to an apogee of 4,600 miles (7,400 km), to be commanded by Frank Borman in March 1969. Of all the components of the Apollo system, the LM had the most technical issues. It was behind schedule and when LM-3 was shipped to the Kennedy Space Center in June 1968, over 101 separate defects were discovered. Grumman Aircraft Engineering Corporation, which was the lead contractor for the LM predicted that the first man-rated LM, to be used for the D mission, would not be ready until at least February 1969, delaying the entire sequence. George Low, the manager of the Apollo Spacecraft Program Office, proposed a solution in August 1968. Since the CSM would be ready three months before the Lunar Module, they could fly a CSM-only mission in December 1968. But instead of just repeating the C mission that would fly the CSM in Earth orbit, they could send the CSM all the way to the Moon and maybe even enter into orbit. This mission was dubbed "C-Prime" (an imaginary letter between C and D). This new mission would allow NASA to practice procedures for a lunar flight that would otherwise have to wait until Apollo 10, the F mission. There were also concerns from the Central Intelligence Agency that the Soviet Union was planning their own circumlunar flight for December to upstage the Americans once again (see Zond program). McDivitt's crew—who had grown accustomed to working with LM-3 and preparing for its flight—was kept on the D mission which now became Apollo 9, while Borman's crew would fly the CSM lunar orbit mission on Apollo 8, and the E mission was canceled. The swap of crews was also decisive in who would be the first man to walk on the Moon. Pete Conrad was backup commander for McDivitt's crew, and by the process of crew rotation, would have been in line for commander of Apollo 11 three flights later. Neil Armstrong got this honor by virtue of being Borman's backup commander.
== Follow-on lunar missions == NASA contracted to have 15 flight-worthy Saturn V rockets produced. Apollo 11 achieved the first landing with the sixth Saturn V, leaving nine for future landings. The following landing sites were chosen (see clarification below) for these missions, planned to occur at intervals of approximately four months through July 1972. This list of landing sites was not compiled by the Apollo Site Selection Board (ASSB), or its various sub-groups, which made the actual landing site selections one to two flights in advance. This list was compiled by a consulting firm, and was only a set of planning tools and suggestions. The ASSB would have selected actual sites for the cancelled Apollo missions, and since these missions never went through the site selection process, the list presented here did not reflect actual planning of the Apollo Program Office or NASA HQ, as referenced in To A Rocky Moon, by Donald Wilhelms.
Apollo 12 (H1) November 1969, Ocean of Storms (Surveyor 3 site) Apollo 13 (H2) April 1970, Fra Mauro highlands Apollo 14 (H3) Littrow crater Apollo 15 (H4) Censorinus crater The last five missions were J-class missions using the Extended Lunar Module, capable of three-day stays on the Moon and carrying the Lunar Roving Vehicle:
Apollo 16 (J1) Descartes Highlands Apollo 17 (J2) Marius Hills Apollo 18 (J3) Copernicus crater Apollo 19 (J4) Hadley Rille Apollo 20 (J5) Tycho crater (Surveyor 7 site) As the later missions were up to three years in the future, little detailed planning was made, and a variety of landing sites were given for some flights. According to "NASA OMSF, Manned Space Flight Weekly Report" dated July 28, 1969, Apollo 18 would have landed at Schröter's Valley in February 1972, Apollo 19 in the Hyginus rille region in July 1972, and Apollo 20 in Copernicus crater in December 1972. Other proposed landing sites and schedules for the last three missions included Gassendi crater (Apollo 18, July 1973), Copernicus (Apollo 19, December 1973), and Marius Hills or Tycho crater (Apollo 20, July 1974). As a number of ambitious Apollo Applications Programs were planned, it was still hoped in 1969 that further Saturn V launch vehicles could be contracted, allowing for more ambitious lunar missions. In the NASA report "Scientific Rationale Summaries for Apollo Candidate Lunar Exploration Landing Sites" from March 11, 1970, Apollo 18 is targeted for Copernicus, and Apollo 19 is assigned Hadley rille (the eventual landing site of Apollo 15). The Apollo 20 mission had been canceled two months before, but the report still suggested its target, Hyginus rille, possibly as an alternative Apollo 19 landing site.