ALSS Lunar Base Credit - © Mark Wade

The ALSS (Apollo Logistics Support System) Lunar Base would require a new development, the LM Truck, to allow delivery of up to 4100 kg in payload to the lunar surface. This would allow larger surface shelters and MOLAB pressurized roving laboratories to be landed on the moon, allowing two astronauts to make extensive exploration of selected areas of the lunar surface. No elements of ALSS were funded for development prior to the cancellation of further Saturn V production in June 1968.

As of 1966 it appeared that the original buy of 12 Saturn IB's and 15 Saturn V's would be used up by the end of 1968 and March 1970, respectively. Extended Lunar Surface Missions would begin in March 1970. Two to four Saturn V launches per year would be needed to support one to two surface missions a year.

Evolution to a lunar base would go 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). Modules developed for ALSS or LEM Truck could be used in LESA systems for commonality and to reduce development costs. The end result would be ever-expanding permanent stations on the moon.

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

:
• 2 men/2 days - Apollo
• 2 men/14 days - AES - LEM Shelter (2050 kg surface payload - LEM Shelter)
• 2 men/14 to 30 days - ALSS using the LM Truck to deliver a shelter or MOLAB (4100 kg surface payload)
• 2 to 3 men/14 to 30 days - ALSS using the LM Truck and an Apollo Service Module as an additional braking stage to deliver a LASSO shelter or larger MOLAB (7900 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 of 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.

The ALSS flights would also require several new elements:

• Production of additional Saturn V vehicles.
• Extended CSM, as developed for the Extended Life Orbital Missions of Apollo Applications and AES. This would shuttle from three to four astronauts from earth orbit, to lunar orbit, and back to earth.
• LEM Taxi, as developed for the AES base, to shuttle two to three astronauts from lunar orbit to the lunar surface and back.
• LEM Truck, essentially a Lunar Module descent stage adapted for unmanned delivery of payloads of up to 5,000 kg to the lunar surface.
• MOLAB - a mobile pressurized lunar rover - which would provide the crew with both mobility and a home during long-range lunar traverses.
• A Lunar Flying Vehicle - which would provide the crew with the means of returning to the LEM Taxi in case of the MOLAB's breakdown.

A typical Apollo Logistics Support System (ALSS) mission sequence would be exploration of the Kepler crater area. This would involve first landing a LEM Truck with a Molab rover (the alternate payload of a large shelter and a small open cabin lunar roving vehicle was considered less desirable). A second Saturn V launch would deliver two astronauts in a LEM Taxi. After setting up a geophysical monitoring station they would embark on a 14-day, 400-km exploratory traverse, studying five identified geological features. The crew would then return to earth. A third Saturn V launch would land a second LEM Truck, and the fourth the second crew, which would conduct a second, 480 km traverse covering six additional features. In total, 12 of the 14 features of interest within 200 km of Kepler would be inspected on two manned missions requiring four Saturn V launches.

It would be possible to achieve a significant extension of lunar surface capability by using the Service Module (SM) for lunar descent, in addition to the LM descent stage. This would increase payload capacity so that the entire volume of the Apollo Spacecraft-LM Adapter (SLA) could be outfitted as a mini-base of superior capacity and capability to the LM Shelter. In this LASS concept (LM Adapter Surface Station) the LM ascent stage was replaced by the SLA mini-base and the position of the SM was reversed. The SLA mini-base carried consumables for 192 man-days on the lunar surface and 5,090 kg cargo, amounting to a total payload weight of 7,700 kg. This meant that successive crews of two astronauts could stay for a total of 96 days. The SLA included a Lunar Roving Vehicle (LRV) and a Lunar Flying Unit (LFU) for the astronauts. Its cargo included 2,700 kg of mobility fuel for the LRV and LFU, plus 1,800 kg of scientific equipment.

The SLA mini-base would be delivered first by an unmanned shelter-logistics Saturn V launch vehicle. A second Saturn V launch would deliver two astronauts in an LM Taxi to the mini-base. Since it would not be practical to leave one astronaut in the CSM circling the moon for 100 days, the third astronaut would return in the CSM back to Earth. Three months later, a third mission would be launched to return the lunar base crew to Earth.

Alternatively, the third mission would deliver a new crew in a new LM Taxi to the surface, with the first surface crew returning in the third mission's CSM. This scenario used existing Apollo hardware elements and achieved two thirds of the surface payload of the LESA concept, which required development of completely new lunar lander hardware.

In order to avoid the costly third launch while retaining the single surface-crew scenario, a small lunar orbiting base could be included with sufficient capacity for the astronauts in lunar orbit to be active during a 60-day stay-time in lunar orbit while the surface crew conducted their exploration. For this purpose, the SLA was extended by a cylindrical section to provide enough volume to house both a Lunar Orbit Base (LOB) and the Lunar Surface Base (LSB). A standard Saturn V could deliver the resulting configuration. Delivery would be unmanned, followed by a second launch carrying a CSM, modified to house 4 astronauts and an LM Taxi with a capacity for 2 astronauts. The LSB would need a quiescent capability of 100 days, and the LM Taxi 60 days.

In this scenario the first Saturn V launch would place the unmanned SLA LOB/LSB into lunar orbit. This would be followed by the Saturn V launch with four crew and an Extended CSM and LM Taxi. After braking into lunar orbit, the two lunar surface astronauts would enter the LM Taxi and separate from the CSM. Meanwhile the CSM with the two lunar orbit astronauts would dock with the SLA LOB/LSB complex in lunar orbit. From there they would monitor and control the unmanned descent of the LSB, using the first SM and then the LM descent stage. Preceding or following the LSB landing, the surface astronauts would descend in the LM Taxi and land at the base site.

The cargo delivered to the surface in the LSB, along with the consumables, was 3,100 kg for 2 men and 60 days, corresponding to 25.7 kg/man-day.

Apollo Expedition Apollo LOR Expedition... Credit- NASA

Crew Size: 2. Design Life: 14 to 30 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 Truck.  Other Designations: LM Truck. Class: Manned. Type: Lunar Logistics. Destination: Moon. Nation: USA. Manufacturer: Grumman.

  The LM Truck was an LM Descent stage adapted for unmanned delivery of payloads of up to 5,000 kg to the lunar surface in support of a lunar base using Apollo technology. The LM Truck would make precision landings using radio landing beacons prepositioned by the lunar base staff.

  Apollo Lunar Base Credit- NASA

  The Truck could be accompanied by an Apollo CSM on a purely lunar orbital mission. Alternatively two Trucks could be delivered in a single unmanned Saturn V mission, with a partially-fueled Apollo Service Module being used for the lunar orbit insertion maneuver. Items added to the basic descent stage: Navigation and guidance system (126 kg); stability and control system (49 kg); reaction control system (250 kg); communications (21 kg); ECS for equipment (58 kg).

  The LM Truck concept used a modified LM descent stage as a Lunar Logistic Vehicle. The LM ascent stage was removed and replaced by a cargo platform. Subsystems now on the LM ascent stages necessary for landing (e.g., reaction control system (RCS) and guidance) were added. The basic flight plan assumed a manned Command Service Module (CSM), Lunar Orbit Rendezvous (LOR) mode. The LM Truck would be landed by remote control from the manned CSM, which would then return to earth. The crew that would actually unload the Truck would arrive months later in a separate CSM, and ride an LM Taxi to a surface rendezvous with the Truck. However, a totally unmanned flight mode was possible with proper guidance and navigation modification. As conceived, the LM Truck weighed 10,000 kg and had the same propellant capacity and payload capability as the LM descent stage. The LM Truck capability would benefit from an "augmented" LM development.

  Length: 3.20 m (10.40 ft). Maximum Diameter: 9.37 m (30.74 ft). Mass: 8,990 kg (19,810 lb). Main Engine Thrust: 44.041 kN (9,901 lbf). Main Engine Propellants: N2O4/Aerozine-50. Main Engine Propellants: 7,420 kg (16,350 lb). Main Engine Isp: 311 sec. Electrical System: Batteries. Associated Launch Vehicle: Saturn V.

• Molab.  Other Designations: Moderate Capacity Mobile Laboratory. Manufacturer's Designation: Mobile Lunar Laboratory. Class: Manned. Type: Lunar rover. Destination: Moon. Nation: USA.

  The moderate capacity mobile laboratory (MOLAB) concept was studied in two NASA/MT contracts to determine configurations and capabilities of vehicles in the 2950 to 3850 kg class. Designed for delivery by the LM Truck, MOLAB was to be capable of surviving six months quiescent storage on the lunar surface, and then be activated to support two men in a pressurized cabin on a 14-day mission with a 7-day stay time contingency in a stationary mode.

  A typical configuration consisted of a four wheel vehicle having an internal pressurized volume of 12.8 m3 plus an additional 3.46 m3 airlock. The MOLAB would take advantage of any subsystem improvements evaluated in the Early Lunar Shelter studies such as cryogenic gas storage systems. In essence, a MOLAB related to an Early Lunar Shelter as the MOLEM to the LM shelter. Stay time or experimental payload was traded for mobility. Although the MOLAB was sized for a two man, 14 day mission, the concept could to establish tradeoffs of crew size and stay time in terms of weight and subsystem requirements. A three man 21 day 900 km traverse would require a MOLAB weighing 3810 kg. Average speed would be 10 kph and 320 kg of scientific experiments drawing 112 kW-hr of power could be accommodated. Mass breakdown was as follows:

  Fixed Equipment

  • Structure: 636 kg
  • Power supply: 220 kg
  • Mobility: 1,485 kg
  • EC/LSS: 324 kg
  • Astrionics: 320 kg
  • Subtotal: 2985 kg

  Expendables

  • Hydrogen for power: 88 kg
  • Oxygen for power: 347 kg
  • Oxygen for crew: 216 kg
  • Others (food, LiOH, etc): 174 kg
  • Subtotal: 825 kg

  Total: 3810 kg

  Apollo LASS Credit- NASA

  Another variant would take two men up to a total range of 396 km at a maximum velocity of 16 km/hr on compacted soils, 9.8 km/hr on maria. Turn radius 7 m; locomotion energy .39 k2-hr/km in uplands. 3,732 kg total mass breakdown: 1,036 kg cabin systems; 825 kg mobility; 282 kg power; 210 kg electronics; 340 kg scientific equipment; 466 kg for Lunar Flying Vehicle (rocket platform for emergency return to LM Taxi); 126 kg for tie downs; and 437 kg for expendables (fuel cell propellants and crew oxygen).

  Crew Size: 2. Design Life: 30 days. Length: 6.15 m (20.17 ft). Maximum Diameter: 3.18 m (10.43 ft). Habitable Volume: 5.66 m3. Mass: 3,732 kg (8,227 lb). Electrical System: Fuel Cells. Electric System: 160.00 kWh.

• Apollo ELS.  Other Designations: Early Lunar Shelter. Class: Manned. Type: Lunar Habitat. Destination: Moon. Nation: USA. Agency: NASA. Manufacturer: Airesearch.

  The capabilities of a lunar shelter not derived from Apollo hardware were surveyed in the Early Lunar Shelter Study (ELS), completed in February 1967 by AiResearch. The study was an evaluation of configurations suitable for use with LM Truck capability (4700 kg).

  Lunar Colony NASA Lunar Colony, NASA 1970 Concept... Credit- NASA via Marcus Lindroos

  The primary objective was the evaluation and conceptual design of two-man lunar shelters for comparison with competing concepts such as the LM Shelter. This was later expanded to include evaluation of three-man shelters. Stay-time capabilities were evaluated in terms of crew size, and duty cycles with and without EVA activity.

  The EVA duty cycle consisted of 9 hours/day: 6 hours (one man) on a "Local Scientific Survey Module" (LSSM) and a non-concurrent 3 hour EVA on foot in the ELS vicinity. Based on the above, expendable consumption rates were established for crew metabolism, environmental control and life support (EC/LSS), electrical power supply (EPS) and fluid storage.

  It was concluded that a minimum design volume of 14 m3 was desirable for a two man, 14 day mission. Final designs were based on a 21 m3 volume. Basic shelter equipment included rechargeable portable life support systems (PLSS) (3 per man), fuel cells for EPS, cryogenic supercritical storage for fuel cell reactants and life support gases, and Li0H for C02 removal.

  The study indicated a stay time capability of 50 days for two men within the 4700 kg constraint. Of this 787 man-hours would be available for scientific activities, and 450 man-hours of that for surface studies. A 1578 kg scientific payload could be accommodated, with 600 kW-hours of electricity available for scientific experiments. The ELS could conduct a 912 km lunar surface traverse used together with an LSSM. Capabilities included the ability to deploy scientific stations at various surface points and drill 30 m boreholes for subsurface studies.

  With a three-man crew total stay-time would be reduced to 43 days, but man-hours of scientific activities would be increased to 1,050. A two-man crew on an astronomy mission with an OAP telescope could remain on the surface for 66 days. Mass breakdown for the 3-man shelter, 43-day scenario was as follows:

  Fixed Equipment

  • Structure: 610 kg
  • EPS: 338 kg
  • Fluid storage: 283 kg
  • EC/LSS: 317 kg
  • Crew provisions: 236 kg
  • Astrionics: 109 kg
  • Scientific Equipment: 1573 kg
  • Subtotal: 3467 kg

  Expendables

  • Food: 111 kg
  • Water: 103 kg
  • PLSS Canisters: 269 kg
  • High-pressure oxygen: 57 kg
  • Cryogenic oxygen: 551 kg
  • Hydrogen: 60 kg
  • Personal hygiene/waste management supplies: 53 kg
  • Subtotal: 1203 kg

  Total: 4670 kg

• Apollo LASS.  Other Designations: LM Adapter Surface Station. Class: Manned. Type: Lunar Habitat. Destination: Moon. Nation: USA.

  In the LASS (LM Adapter Surface Station) lunar shelter concept, the LM ascent stage was replaced by an SLA 'mini-base' and the position of the Apollo Service Module (SM) was reversed. In comparison to the LM Shelter concept, this provided a lunar mini-base of superior capacity and capability. The SM was used for lunar orbit insertion and the first portion of descent to the lunar surface. The LM descent stage was used for final touchdown.

  The SLA "mini-base" carried consumables for 192 man-days on the lunar surface and 5,090 kg cargo, amounting to a total payload weight of 7,700 kg. This meant that a crew of two astronauts could stay for 96 days. The SLA included a Lunar Roving Vehicle (LRV) and a Lunar Flying Unit (LFU) for the astronauts. Its cargo included 2,700 kg of mobility fuel for the LRV and LFU, plus 1,800 kg of scientific equipment.

  The SLA mini-base would be delivered first by an unmanned shelter-logistics launch vehicle, followed by a personnel carrier launch which delivered two astronauts in an LM Taxi for the mini-base. Since it would not be practical to leave one astronaut in the CSM circling the moon for 100 days, the third astronaut flew the CSM back to Earth. Three months later, a third mission would be launched to return the lunar base crew to Earth.

  In order to avoid the costly third launch, a small lunar orbiting base could be provided offering sufficient capacity for the astronauts in orbit to be active during their long stay-time in orbit. For this purpose, the SLA was extended by a cylindrical section to provide enough volume to house the Lunar Orbit Base (LOB) and the Lunar Surface Base (LSB). The resulting LASSO configuration could be delivered by a standard Saturn V. Delivery was unmanned, followed by a second launch carrying a CSM, modified to house 4 astronauts and an LM Taxi with a capacity for 2 astronauts. The LSB had a quiescent capability of 100 days, and the LM Taxi 60 days.

  First, the unmanned SLA LOB/LSB was delivered into lunar orbit, followed by the personnel transport launch. The two lunar surface astronauts occupied the LM Taxi, while the CSM with the two lunar orbit astronauts was transferred to the SLA LOB/LSB complex. There they controlled the unmanned descent of the LSB, using the first SM and the LM descent stage. Preceding or following the LSB landing, the surface astronauts descend in the LM Taxi.

  The cargo delivered to the surface in the LSB, along with the consumables, was 3,100 kg for 2 men and 60 days, corresponding to 25.7 kg/man-day.

  Mass: 7,700 kg (16,900 lb). Associated Launch Vehicle: Saturn V.

• 1967 May 24 - NASA realigned its Apollo and AAP launch schedules following the Apollo 204 accident in January. - Launch Vehicle: Saturn I, 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 I, 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 I, 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 I, 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.