Apollo Lunar Module Credit - © Mark Wade Media Gallery

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.

• 1963 December 26 - Extension of Apollo systems to permit more extensive exploration of the lunar surface. - Launch Vehicle: Saturn V.

  MSFC Director Wernher von Braun described to Apollo Spacecraft Program Manager Joseph F. Shea a possible extension of Apollo systems to permit more extensive exploration of the lunar surface. Huntsville's concept, called the Integrated Lunar Exploration System, involved a dual Saturn V mission (with rendezvous in lunar orbit) to deliver an integrated lunar taxi/shelter spacecraft to the Moon's surface.Additional Details: Extension of Apollo systems to permit more extensive exploration of the lunar surface. (21895).

• 1965 August 1 - Grumman final report on a study of LEM utilization for AES Earth-orbit missions. -

  Grumman submitted to NASA its final report on a study of AES for Earth-orbit missions (conducted under the firm's contract for a LEM utilization study). The five-volume report comprised general engineering studies, mission and configuration descriptions for different groups of experiments (both NASA's and those for the Air Force's Manned Orbiting- Laboratory), and a cost and schedule analysis.Additional Details: Grumman final report on a study of LEM utilization for AES Earth-orbit missions. (21921).

• 1966 December 1 - John H. Disher released the report by a study group at Headquarters on various modified lunar modules suitable for a lunar exploration program as part of AAP. -

  These modified craft took the form of a LM taxi, ferry and logistics craft, a LM shelter, and an 'augmented' LM. Disher authorized MSC to extend its engineering studies contract with Grumman to further define such modified LM configurations. He also asked MSFC to try to increase the Saturn V's translunar injection capability to 46 720 kg. These actions, he explained, afforded an opportunity to pursue any of several alternatives once future landing levels were known.

• 1966 October 19 - MSFC Director Wernher von Braun described to his MSC counterpart Robert R. Gilruth his ideas for transferring to Houston the bulk of MSFC's lunar exploration studies and development contracts. -

  (As a result of the 13-15 August Lake Logan meeting, Deputy Administrator Robert C. Seamans, Jr., had designated MSC the lead Center for lunar science.) von Braun proposed that planning for AAP-type lunar traverses and a wide variety of lunar scientific experiments (including a scientific package of experiments to he emplaced near landing sites) be transferred to Houston. On the other hand, he believed that lunar roving and flying devices, the AAP lunar drill, and the lunar surveying system should be retained at Huntsville, saying that these projects were of an engineering rather than a scientific nature and that, with MSFC's in-house capability for engineering work of this type, his Center could make substantial-and cost- effective-contributions to lunar exploration.

• 1968 January 5 - NASA lunar exploration program developed for the period from the first lunar landing to the mid-1970s. -

  A lunar exploration program had been developed which would cover the period from the first lunar landing to the mid-1970s. The program would be divided into four phases: (1) An Apollo phase employing Apollo hardware. (2) A lunar exploration phase untilizing an extended LM with increased landed payload weight and staytime capability. (3) A lunar orbital survey and exploration phase using the AAP-1A carrier or the LM/ATM to mount remote sensors and photographic equipment on a manned polar orbit mission. (4) A lunar surface rendezvous and exploration phase which would use a modified LM in an unmanned landing to provide increased scientific payload and expendables necessary to extend an accompanying manned LM mission to two weeks duration.

• Baker, David, The History of Manned Spaceflight, Crown, New York, 1981. The best overview of America's manned space programs up to Skylab. Information and details not available anywhere else. Unfortunately out of print and difficult to locate.

• Henderson, C William, Advanced in the Astronautical Sciences, Vol 18, "Extended Lunar Exploration", 1964, p 615.

• National Space Goals for Post-Apollo Period, House of Representatives Hearings, 1965.

• Arthur, George R, Advanced in the Astronautical Sciences, Volume 10, "Lunar Spacecraft Designs", 1963, p. 52.

• Salter, Thomas R, Advanced in the Astronautical Sciences, Vol 18, "Advanced Lunar Transportation Systems", 1964 / NASA Contract NAS8-5027.

• Evans, Thomas C, Advanced in the Astronautical Sciences, Vol 18, "Extended Lunar Exploration", 1964, p 480.