Encyclopedia Astronautica
AES Lunar Base

ALSS Lunar Base
Apollo Lunar Support Systems Base Elements
Credit: © Mark Wade
Apollo Lunar Base
Credit: NASA
American manned lunar base. Cancelled 1968. AES (Apollo Extension Systems) was planned as the first American lunar base. It would involve minimal modification of Apollo hardware. The Apollo CSM would be modified for long duration lunar orbit storage.

Two versions of the Apollo LM would be developed: the LM Taxi, and the LM Shelter. Surface mobility would be provided by an open cab lunar rover within the 2050 kg lunar surface payload capability of the LM Shelter. This preliminary base would require two Saturn V launches to allow two astronauts to explore the vicinity of their LM Shelter over a two week period. Development was actually begun in May 1966 with plans for a first mission in March 1970. But subsequent cutbacks and then cancellation of further Saturn V production led to the project being completely abandoned in June 1968.

The AES flights would also require several new elements:

  • Production of additional Saturn V vehicles, with launches to start in 1970.
  • Extended CSM, as developed for the Extended Life Orbital Missions of Apollo Applications. Definition began in mid-1965, with development starting in April 1966 and fabrication in spring 1967. First article would be delivered for payload integration in April 1969 with first flight in February 1970. The Extended CSM had the capability to operate with one astronaut for 30 days in lunar orbit. This affected primarily consumables (Lox/H2 for the fuel cells, RCS propellants, food, gases, and other life support consumables).
  • LEM Shelter. Definition began in mid-1965, and with development starting in September 1966 and fabrication in February 1967, first flight would be in February 1970. The LM Shelter replaced the propellants and engine of the basic LM ascent stage with necessary consumables to support two weeks of lunar exploration.
  • LEM Taxi. Definition began in mid-1965, and with development starting in May 1966 and fabrication in September 1967, first flight would be in April 1970. The LM Taxi could deliver (but not house) two astronauts to the surface and return them to an orbiting CSM after a two-week lunar surface stay in the separately-landed shelter. The LM Taxi was an LM modified slightly to give it the capability for a 14-day quiescent (inactive) lunar stay time, in addition to 3 days (active) operational time.
  • Lunar mobility vehicles - NASA studied a vast array of rovers, hoppers, crawlers, walkers, and even worms over the years. The AES vehicles (probably an open-cabin rover and a short-distance hopper) would have to be accommodated within the 2050 kg surface payload of the lunar shelter. No go-ahead for development of a specific model was given prior to AES cancellation. The two-man, open-cab lunar rover actually used beginning with the Apollo 15 mission was a relatively trivial development when NASA was at its peak. Development was authorized in May 1969; Boeing was selected as contractor in October 1969; and the first rover was on the moon in July 1971.

In the AES scenario the LM Shelter would be delivered by a Saturn V launch sending a manned Apollo CSM and the LM Shelter towards the moon. As in a standard Apollo flight, the CSM would transpose and dock with the LM Shelter, and then pull it away from the S-IVB stage. After the CSM had braked the combination into lunar orbit, the automated LM Shelter would separate. The crew would merely orbit above the moon in the CSM until the automated LM Shelter had landed, and then return to Earth. A second Saturn V launch, using an Extended CSM and a LM Taxi, would transport a crew to the LM Shelter. Because of the expected interval between first and second landings, the LM Shelter would have to be given a 90-day quiescent capability. The second flight would land two of the crew using the LM Taxi while the 30-day CSM waited with a single astronaut in lunar orbit. After landing, the crew would shut down the LM Taxi and activate the shelter system. Two weeks later, the LM Taxi would be reactivated and the crew would return to the CSM and back to Earth.

Mission duration could be doubled by modifying the S-IVB third stage of the Saturn V for operation in lunar space and by providing a 40-day quiescent capability for an unmanned CSM in lunar orbit. This would allow all three astronauts to be landed on the Moon for a 30-day stay time.

As the Viet Nam War and public indifference cut into NASA budgets, these plans were continuously cut-back. This can be seen in the number of Saturn V launches allocated by NASA for Apollo Applications Program lunar activities:

  • December 1966: 13 Saturn V flights
  • May 1967: 12 Saturn V flights
  • October 1967: 6 Saturn V flights
  • June 1968: All post-Apollo lunar launches deleted.

Evolution to a lunar base would have gone from the basic Apollo hardware to AES (Apollo Extension Systems) to ALSS (Apollo Logistics Support System using the LEM Truck), and then LESA (Lunar Exploration System for Apollo). The end result would be ever-expanding permanent stations on the moon.

A typical vision of post-Apollo lunar exploration consisted of the following phases:

  • 2 men/2 days - Apollo
  • 2 men/14 days to 30 days - AES - LEM Shelter (2050 kg surface payload - LEM Shelter)
  • 2 men/14 to 30 days - ALSS using the LM Truck to deliver a STEP shelter or MOLAB (4100 kg surface payload)
  • 3 men/90 days - LESA I (10,500 kg surface payload)
  • 3 men/90 days - LESA I + MOLAB (12,500 kg surface payload)
  • 6 men/180 days - LESA II with shelter and extended range roving vehicle (25,000 kg surface payload)

In a comparison lf lunar base approaches, the basic Apollo hardware scenario for thorough exploration of a single location would consist of a single manned lunar reconnaissance landing of the selected base site, followed by six Apollo launches over the next six quarters - total, 14 man-days on the moon for 7 Saturn V launches. The AES or ALSS approach would follow the single reconnaissance flight by three pairs of cargo landings and manned landings, resulting in a total of 86 man-days on the moon for the same number of Saturn V launches. The LESA approach, with a cargo lander followed by two manned landings in sequence to the same large shelter and rover, would allow 542 man-days on the moon. ALSS development would cost around $500 million, and LESA cost $1.45 billion. In terms of cost per man-day on the moon, either approach would pay off on the very first mission.


Crew Size: 2.

AKA: Apollo Extension Systems.

More... - Chronology...

Associated Countries
Associated Spacecraft
  • Apollo CSM American manned lunar orbiter. 22 launches, 1964.05.28 (Saturn 6) to 1975.07.15 (Apollo (ASTP)). The Apollo Command Service Module was the spacecraft developed by NASA in the 1960's as a standard spacecraft for earth and lunar orbit missions. More...
  • Apollo LM Shelter American manned lunar habitat. Cancelled 1968. The LM Shelter was essentially an Apollo LM lunar module with ascent stage engine and fuel tanks removed and replaced with consumables and scientific equipment for 14 days extended lunar exploration. More...
  • Apollo LM Taxi American manned lunar lander. Cancelled 1968. The LM Taxi was essentially the basic Apollo LM modified for extended lunar surface stays. More...
  • LSSM American manned lunar rover. Study 1968. The Bendix Local Science Survey Module was a forerunner of the Lunar Rover. The LSSM was a small size vehicle used to support a local manned survey. It was proposed for delivery with an LM Shelter. More...
  • MOBEV F2B American manned lunar flyer. Cancelled 1968. The F2B was the MOBEV selected configuration for a multi-man surface-to-surface flying vehicle. Maximum operational mass with 2 astronauts and payload, 844 kg. More...

See also
  • Lunar Bases The Lunar Base never seemed to be a high priority to space visionaries, who were mainly interested in getting on to Mars. It was usually seen as a proving ground for Mars vehicle technology, or as a place to mine propellant for use in a larger space infrastructure. More...

Associated Launch Vehicles
  • Saturn V American orbital launch vehicle. America's booster for the Apollo manned lunar landing. The design was frozen before a landing mode was selected; the Saturn V could be used for either Earth-Orbit-Rendezvous or Lunar-Orbit-Rendezvous methods. The vehicle ended up with the same payload capability as the 'too large' Nova. The basic diameter was dictated by the ceiling height at the Michoud factory selected for first stage manufacture. More...

AES Lunar Base Chronology

1967 May 24 - . LV Family: Saturn I; Saturn V.
  • NASA realigned its Apollo and AAP launch schedules following the Apollo 204 accident in January. - . Nation: USA. Spacecraft: Orbital Workshop; Skylab; AES Lunar Base; ALSS Lunar Base. Because of the Apollo 204 accident in January and the resulting program delays, NASA realigned its Apollo and AAP launch schedules. The new AAP schedule called for 25 Saturn IB and 14 Saturn V launches. Major hardware for these launches would be two Workshops flown on Saturn IB vehicles, two Saturn V Workshops, and three ATMs. Under this new schedule, the first Workshop launch would come in January 1969.

1967 October 3 - . LV Family: Saturn I; Saturn V.
  • Budgetary cutbacks reduced AAP lunar activity to four missions and Saturn V Workshops to 17 Saturn IB and 7 Saturn V launches. - . Nation: USA. Spacecraft: Orbital Workshop; Skylab; AES Lunar Base; ALSS Lunar Base. NASA Hq issued a revised AAP schedule incorporating recent budgetary cutbacks. The schedule reflected the reduction of AAP lunar activity to four missions and of Saturn V Workshop activity to 17 Saturn IB and 7 Saturn V launches. There would be two Workshops launched on Saturn IBs, one Saturn V Workshop, and three ATMs. Launch of the first Workshop was scheduled for March 1970.

1968 January 9 - . LV Family: Saturn I; Saturn V.
  • Budgetary restraints required additional cuts in AAP to three Saturn IB and three Saturn V launches. - . Nation: USA. Spacecraft: Orbital Workshop; Skylab; AES Lunar Base; ALSS Lunar Base. NASA budgetary restraints required an additional cut in AAP launches. The reduced program called for three Saturn IB and three Saturn V launches, including one Workshop launched on a Saturn IB, one Saturn V Workshop, and one ATM. Two lunar missions were planned. Launch of the first Workshop would be in April 1970.

1968 June 4 - . LV Family: Saturn I; Saturn V.
  • New AAP schedule decreased to 11 Saturn IB flights and one Saturn V flight. - . Nation: USA. Spacecraft: Orbital Workshop; Skylab; AES Lunar Base; ALSS Lunar Base. NASA released a new AAP launch readiness and delivery schedule. The schedule decreased the number of Saturn flights to 11 Saturn IB flights and one Saturn V flight. It called for three Workshops. One of the Workshops would be launched by a Saturn IB, and another would serve as a backup. The third Workshop would be launched by a Saturn V. The schedule also included one ATM. Launch of the first Workshop would be in November 1970. Lunar missions were no longer planned in the AAP.

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