 | ALSS Lunar Base
Credit - © Mark Wade
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Other Designations: Apollo Extension Systems. Class: Manned. Type: Lunar Base. Destination: Moon. Nation: USA. 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. Design Life: 14 days. Associated Launch Vehicle: Saturn V. - Apollo LM Taxi. Other Designations: LM Taxi. Class: Manned. Type: Lunar Lander. Destination: Moon. Nation: USA. Manufacturer: Grumman.
The LM Taxi was essentially the basic Apollo LM modified for extended lunar surface stays. This was expected to be the workhorse of both Apollo Applications Extended Lunar Surface Missions beginning in 1970 and still be used to shuttle crews to the surface to larger LESA (Lunar Exploration System for Apollo) in the mid- to late- 1970's. Changes included additional water, oxygen, LH2, and Lox tankage in the descent stage in the payload bays; fuel cells in the ascent stage; a redundant Lox tank in the ascent stage over the back of the LM; and additional micrometeorite and radiation shielding. This would permit the LM to accommodate a crew of three with the capability for a 14-day quiescent (inactive) lunar stay time, in addition to 3 days (active) operational time. The LM Taxi would land near the previously-landed LM Shelter or LESA Shelter, where the crew would spend most of its time during surface explorations lasting from 14 days to three months. Crew Size: 3. Design Life: 14 days. Length: 6.37 m (20.89 ft). Maximum Diameter: 4.27 m (14.00 ft). Habitable Volume: 6.65 m3. Mass: 14,700 kg (32,400 lb). Main Engine Thrust: 44.041 kN (9,901 lbf). Main Engine Propellants: N2O4/Aerozine-50. Main Engine Propellants: 10,500 kg (23,100 lb). Main Engine Isp: 311 sec. Spacecraft delta v: 3,700 m/s (12,100 ft/sec). Electrical System: Fuel Cells. Associated Launch Vehicle: Saturn V.
- Apollo LM Shelter. Other Designations: LM Shelter. Class: Manned. Type: Lunar Habitat. Destination: Moon. Nation: USA. Manufacturer: Grumman.
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. Work was planned to begin in 1966, with 1-2 missions per year beginning in 1970 after accomplishment of the manned lunar landing goal. In the event, only the Lunar Rover vehicle, used in the later Apollo missions, ever saw actual use. In a scenario requiring two Saturn V launches, the LM shelter would be landed on one launch, with a manned Apollo CSM accompanying it into lunar orbit but conducting lunar orbit surveying operations only. The CSM and its crew would then return to earth. A second Saturn V launch would deliver a CSM and LM Taxi combination to lunar orbit. The crew would take the LM taxi to the surface, landing near the shelter. In order to house the astronauts during their 14-day stay a two-man STEP expandable shelter was an alternate to the LM Shelter. The STEP could be delivered by an LM descent stage together with a slightly higher discretionary payload than the LM shelter could carry. Either shelter would be delivered first by a logistics flight where the crew merely orbited in the CSM until the automated shelter-carrying LM had landed, and then returned to Earth, thus being able to use the Apollo CSM unchanged. The logistics flight was followed by the personnel transport. Because of the interval between first and second landing, the shelter-carrying LM had to be given a 90-day quiescent capability. The second flight would land the crew using the LM Taxi while the 30-day CSM waited in lunar orbit. After landing, the crew shut down the LM Taxi and activated the shelter system. Two weeks later, the LM Taxi was reactivated and the crew returned to the CSM and back to Earth.
By modifying the third stage of the Saturn V (S-IVB) for operation in lunar space, and by providing a 40-day quiescent capability for an unmanned CSM in lunar orbit, all three astronauts could be landed on the Moon for a 30-day stay time. Crew Size: 2. Design Life: 14 days. Length: 6.37 m (20.89 ft). Maximum Diameter: 4.27 m (14.00 ft). Habitable Volume: 6.65 m3. Mass: 14,700 kg (32,400 lb). Payload: 2,300 kg (5,000 lb). Main Engine Thrust: 44.041 kN (9,901 lbf). Main Engine Propellants: N2O4/Aerozine-50. Main Engine Propellants: 8,000 kg (17,600 lb). Main Engine Isp: 311 sec. Spacecraft delta v: 2,400 m/s (7,800 ft/sec). Electrical System: Fuel Cells. Associated Launch Vehicle: Saturn V.
- MOBEV F2B. Class: Manned. Type: Lunar Flyer. Destination: Moon. Nation: USA. Agency: NASA. Manufacturer: Bendix.
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. It used differential throttling of the lift thrusters. Eight thrusters were used to provide engine out capability and provide an initial lunar thrust to weight ratio of 3. Two thrusters were mounted at the corners of the body in a slightly canted position to provide yaw control. An active three-axis attitude control system was provided. Continuous communications with the lunar base or roving vehicle during exploration were provided by an S-band system integrated with the PLSS system. Multiple landing capability was provided by reusable friction devices for landing energy absorption. A strap-down inertial guidance system provided the required guidance accuracy.
LFV Concepts Summary
Pogo Single-Crew Surface to Surface
F1A F1B F1C
Fueled Mass(kg) 64 82 310
Range(km) 8 20 170
Crew Size 1 1 1
Development Cost($M) 10.6 11.1 13.4
Development Time(Mos) 24 24 24
Multiman Surface to Surface
F2A F2B F2C F2D F3A F3B F3C F3D
Fueled Mass(kg) 288 392 530 788 529 1074 2066 4209
Range(km) 20 50 100 200 50 200 400 800
Crew Size 2 2 2 2 3 3 3 3
Development Cost($M) 29.1 29.5 30.1 30.9 30.8 32.7 36.8 44.5
Development Time(Mos) 42 42 42 42 42 42 42 42
Surface to Lunar Orbit
F2E F3E
Fueled Mass(kg) 1106 1476
Crew Size 2 3
Development Cost($M) 33.0 34.8
Development Time(Mos) 42 42
Crew Size: 2. Mass: 392 kg (864 lb). Main Engine Propellants: 186 kg (410 lb). Main Engine Isp: 290 sec.
AES Lunar Base Chronology - 1967 May 24 - NASA realigned its Apollo and AAP launch schedules following the Apollo 204 accident in January. - Launch Vehicle: Saturn IB, Saturn V.
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 - Budgetary cutbacks reduced AAP lunar activity to four missions and Saturn V Workshops to 17 Saturn IB and 7 Saturn V launches. - Launch Vehicle: Saturn IB, Saturn V.
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 - Budgetary restraints required additional cuts in AAP to three Saturn IB and three Saturn V launches. - Launch Vehicle: Saturn IB, Saturn V.
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 - New AAP schedule decreased to 11 Saturn IB flights and one Saturn V flight. - Launch Vehicle: Saturn IB, Saturn V.
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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