The NASA Headquarters Office of Manned Space Flight created its Advanced Manned Missions Program as part of its efforts to put into motion the Integrated Program Plan (IPP) set out in its September 1969 report to the Space Task Group (STG) and endorsed (with serious reservations) in the STG’s report to President Richard Nixon. In January 1970, Philip Culbertson became the program’s director. In a 29 April 1970 memorandum, Lee Scherer, director of the Apollo Lunar Exploration Office, laid out five “tentative” Apollo and post-Apollo lunar program options for Culbertson to present to the NASA Manned Space Flight Management Council in May 1970.
The Council included directors of the main NASA piloted spaceflight centers (Kennedy Space Center in Florida, the Manned Spacecraft Center in Houston, and Marshall Space Flight Center in Huntsville, Alabama). At the time, NASA was thoroughly preoccupied with a review of the Apollo 13 accident, which had scrubbed the planned third manned moon landing on 13 April 1970.
Lee P. Scherer. Image: NASA
All five of Scherer’s options included evidence that budget cuts were beginning to push NASA planning away from the ambitious IPP. For example, the first three options assumed no restart of the Saturn V assembly line, which NASA Administrator Thomas Paine had declared to be permanently closed on 13 January 1970. At the same time, he had announced that Apollo 20 would be cancelled and its Saturn V rocket used to launch the Skylab I Orbital Workshop. The IPP as presented to the STG had included several Saturn V derivatives.
In Scherer’s IPP-based Option 1, Apollo missions would end with Apollo 19 in early 1975. Apollos 18 and 19 were, however, “under review,” so the Apollo Program might conclude as early as 1972. NASA would bring online a six- or 12-man Earth Orbit Space Station (EOSS) and winged reusable Earth-to-Orbit Shuttle (EOS) by 1977. The EOSS would serve as base for reusable piloted Tugs and reusable Nuclear Shuttles, which would reach orbit via the EOS. When mated to a Nuclear Shuttle, a Tug would be capable of reaching the moon.
NASA planned to use this infrastructure in 1981 to establish a Lunar Orbit Space Station (LOSS) with a propellant depot. A Lunar Surface Base (LSB) would follow no earlier than 1985.
This baseline program would, Scherer explained, create a “large gap” in lunar exploration lasting from seven to nine years, during which interest in the moon would “atrophy.” “Reusable hardware generally may be expensive to build, to use and to refurbish,” a prescient Scherer noted, adding that “lunar science objectives do not need the heavy traffic that would support such reusability.” He told Culbertson that the LOSS might not be needed, and that his office viewed neither the Nuclear Shuttle nor the LOSS propellant depot “as clear requirements.”
Image: NASA
Scherer’s Option 2 – which he appeared to favor – was a “Shuttle/Tug lunar program.” The EOS and a reusable piloted Space Tug without EOSS, LOSS, or Nuclear Shuttle would enable piloted lunar orbital and landing missions by 1979, he told Culbertson. He stressed that, to enable this option, lunar mission requirements would need to play a role in the drafting of Shuttle and Tug sizing and performance requirements. As envisioned by Scherer, two Tugs would suffice to place astronauts in lunar orbit, while four Tugs would allow astronauts to land on the moon. A pair of landings at a single site would be sufficient to establish a temporary “minibase” by 1982.
Lunar Viking lander. Image: NASA Marshall Space Flight Center
Option 3 was for NASA to pursue a wholly automated lunar program, which is perhaps not too surprising, given that Scherer had from 1963 to 1967 managed the Lunar Orbiter Program, NASA’s final pre-Apollo automated lunar program. Humans would cease to travel to the moon in 1974 with Apollo 18. NASA would follow Apollo with a series of five automated lunar exploration missions spanning 1976-1980. Each would include an orbiter and a rover capable of long-distance traverses. If based on Viking Mars technology, which was under development at this time, the automated lunar program might cost a total of $1.3 billion.
The automated program would, Scherer told Culbertson, “extend lunar exploration & fill gaps left by Apollo,” “provide precursor data for [a] Lunar Surface Base,” “contribute data toward Mars exploration,” and “offer [an] opportunity for international cooperation,” Scherer explained. The last point reflected the Nixon Administration’s desire to use NASA as a vehicle for cooperation with other countries.
Scherer’s final two options assumed that the Saturn V assembly line would be restarted. His “Stretched-Out Apollo Program” would need two or three additional Saturn V rockets. Beginning with Apollo 18 in 1974, “gap-filler” missions would occur annually, though Apollo 19 might be delayed to 1976 by the launch of the Skylab II Orbital Workshop in 1975. The program would end with Apollo 21 in 1978 or Apollo 22 in 1979.
Designated “J-class,” the missions would each remain on the moon for three days and carry a small open rover to facilitate exploration of their complex landing sites. They would also include technology experiments with application to the LSB, which would be established in 1981.
Scherer’s Option 5 was to turn back the clock to the Administration of President Lyndon Baines Johnson. From 1963 on, NASA and its contractors had proposed a range of Apollo-derived vehicles for advanced space missions, including post-Apollo moon flights. In 1965, these studies had become the basis for the Apollo Applications Program (AAP), which for a time in 1966 included more than 30 piloted Earth-orbital and lunar missions. That Apollo-derived spacecraft might reach the moon in the 1970s was believed likely in some quarters as late as 1969. AAP devolved into a wholly Earth-orbital program during 1968-1969.
Reviving AAP lunar plans would require a NASA budget increase, Scherer told Culbertson. Apollo 19 would fly in early 1975, then a series of five annual dual Saturn V missions would begin in 1976. The first Saturn V of each mission would place an unmanned shelter/cargo lander, a long-traverse rover, and rocket-powered flyers on the moon; the second Saturn V would then deliver a crew for a lunar stay lasting from two to eight weeks. The program would culminate in an LSB in 1981.
It is unclear which (if any) of Scherer’s five options the Manned Space Flight Management Council favored at their May meeting. At the time, NASA Administrator Paine appeared ready to trade away Apollo moon landings to try to ensure development of the IPP space station. In addition, NASA’s piloted spaceflight centers were, as noted earlier, mostly focused on recovery from Apollo 13. NASA lunar exploration ended with the sixth successful manned lunar landing mission, Apollo 17, in December 1972, and would not resume until the Ballistic Missile Defense Organization/NASA automated Clementine spacecraft reached lunar orbit in February 1994.
Reference:
Memorandum with attachment, MAL/Director, Apollo Lunar Exploration Office, to MT/Director, Advanced Manned Missions Program, Post-Apollo Lunar Missions – Input to your May Management Council Presentation, 29 April 1970.
