The Proper Course for Lunar Exploration (1965)

Image credit: NASA.

For a time in the early 1960s, Thomas Evans headed up the Advanced Lunar Missions Study Program in the NASA Headquarters Office of Manned Space Flight. By May 1965, when the 11th Annual Meeting of the American Astronautical Society (AAS) was held in Chicago, Illinois, he had retired from NASA to become a farmer in Iowa. This gave him the freedom to speak his mind about what he felt were the Apollo Program's shortcomings.

 

Evans told assembled members of the AAS that "the idea of a manned [landing] on the [M]oon was so spectacular. . . that [it] dominated most pronouncements and thoughts on the space program." He then declared that the objective had "too much the flavor of a stunt to be the final goal of a $20 billion national effort." Evans argued that 

[Our] situation today is comparable to one which might have occurred during the railroad building era in America a century ago. It is as if the federal government had invested vast sums in the construction of the first railroad spanning the North American continent, but had procurred only a single engine and caboose. . . The first crossing by that engine and caboose would have been a major milestone in man's progress and would have been greeted with enthusiasm and applause. But then those responsible for the program would have faced a major decision. . . Should the project be stopped? Should the engine-caboose be run repeatedly back and forth across the Continent to constantly remind the world of our great achievement? Or should a further modest investment be made in. . . some freight and passenger cars, to convert the system into something of practical value? Only the last solution would have been tenable then, and only a similar constructive approach would seem acceptable now. 

Evans was hopeful that good sense would prevail. He pointed to statements by President Lyndon Baines Johnson and Vice-President Hubert Humphrey (chair of the National Space Council) which he said made clear that "the United States fully intends to explore the [M]oon, not merely to visit it." He explained that the Saturn rockets and Apollo spacecraft NASA had under development would provide "an excellent base upon which to build a broad program of manned. . . lunar exploration beyond the first landing."

He noted that NASA expected to be able to launch six Saturn V rockets per year beginning in 1969. After explaining that "most Saturn Vs will be used for lunar operations since there are only a limited number of credible missions for this vehicle in earth orbital and planetary programs during the early 1970s," Evans outlined four candidate Saturn-Apollo-based lunar exploration programs. 

In the first, the baseline Apollo program, a single Saturn V rocket would launch a Apollo Command and Service Module (CSM) carrying three astronauts and the Lunar Excursion Module (LEM) (as the Apollo Lunar Module — LM — was known at this time). Two astronauts would land on the Moon in the LEM for a one-day stay. They would explore an area 0.2 miles in radius centered on their LEM. The crew would have at its disposal only 250 pounds of payload such as scientific instruments. 

The baseline Apollo Lunar Excursion Module (LEM) on the Moon as envisioned in 1964. Image credit: Grumman/NASA.

Evans' second candidate program would be based on the Apollo Extension System (AES) that NASA had begun to study as early as 1963. This option would, he explained, permit "sophisticated orbital survey. . . to gather data on the entire surface of the [M]oon," as well as lunar surface stays lasting up to 14 days. 

Two Saturn V rockets would be required for each AES lunar surface mission. The first would launch a piloted CSM and an automated cargo LEM loaded with 2500 pounds of supplies and equipment. The CSM would transport the cargo LEM (often called a LEM Shelter) to lunar orbit, then the LEM would separate and land automatically on the Moon. The CSM and its crew would then return to Earth. 

The second Saturn V would launch three astronauts and Apollo CSM and LEM spacecraft "improved" to enable long missions. Two astronauts would land in the improved LEM near the cargo LEM, which would serve as their shelter during their 14-day surface stay. They would use a small surface rover or a pair of flying vehicles to explore an area five miles in radius. 

The third candidate program, based on Apollo Logistic Support System (ALSS) studies, would also use two Saturn Vs per 14-day surface expedition, but would differ from AES in that the LEM Truck, a beefed-up LEM descent stage capable of delivering four tons of payload to the lunar surface, would replace the cargo LEM. The LEM Truck's principal payload, Evans wrote, would be the Mobile Laboratory (MOLAB), a pressurized rover that would permit two astronauts to explore an area 50 miles in radius. 

The Northrup MOLAB pressurized lunar rover would have arrived on the Moon atop of modified LEM descent stage (LEM Truck). The cylinder on top of the tubby pressurized compartment is the docking unit for linking with the Apollo CSM that delivered the MOLAB/LEM Truck to lunar orbit. This was one of several pressurized rover designs put forward in the mid-1960s. Image credit: Northrup/NASA.

Evans noted that, in spite of their impressive capabilities, the AES and ALSS cargo delivery systems would be "inherently inefficient" because astronauts would need to travel to the Moon and back to deliver each automated cargo lander. This would mean that the mass of the CSM systems required for crew support and Earth-return (life support, lunar-orbit departure and course-correction propellants, reentry heat shield, and parachutes) would need to be subtracted from the mass of the payload that the AES and ALSS systems could deliver to the Moon's surface.

Lunar Exploration Systems for Apollo (LESA), the fourth program Evans described, would avoid this inefficiency. LESA, Evans explained, was "a family of shelters, vehicles, and other equipment. . . tailored to support not only short-term reconnaissance operations by two or three astronauts but also semi-permanent scientific stations manned by up to 12 or even 18 men." 

LESA 1 Shelter with rover. Image credit: Boeing/NASA.

The Saturn V-launched LESA Shelter lander would follow a direct-ascent trajectory from Earth to the Moon, so would need no CSM. This would enable delivery of up to 14 tons of payload. Crew delivery at first would be by improved Apollo CSM and an upgraded LEM capable of landing three men on the Moon. The CSM would remain in hibernation in lunar orbit while the crew was on the surface; the LEM would hibernate on the surface while its crew lived in the LESA Shelter.

A 90-day, three-man LESA 1 expedition would explore an area 80 miles in radius; a 365-day, 12-to-18-man LESA 3 outpost made up of additional Shelters and other specialized modules (for example, a nuclear power plant) and relying on advanced direct-ascent landers for crew rotation and resupply would survey an area 200 miles in radius. The former would require a total of three Saturn V launches; the latter, 10 to 17 Saturn V launches. 

Developing the AES would cost an additional $500 million over the $20 billion already committed to Apollo, Evans estimated, while ALSS development would cost $1 billion. Developing LESA 1 would cost $2 billion — just 10% of the amount already committed to Apollo. LESA 3 would evolve from LESA 1 for an additional $800 million.

Evans then proposed a two-phase post-Apollo lunar program. In Phase I, which would be based on AES, ALSS, or LESA 1, astronauts would explore three areas of the Moon judged to be of "major geoscientific interest" totaling up to 1800 square miles ("a meager sample," Evans noted, "of the total 10 million square miles of lunar surface"). In Phase II, which would be based on LESA 3 modified for six astronauts, NASA would maintain an outpost on the Moon for four years. 

Evans compared operations costs of the four programs. He determined that a combination of LESA 1 in Phase I and modified LESA 3 in Phase II would be most economical, with a total cost of less than $8 billion. ALSS/modified LESA 3, with an operations cost of $8.3 billion, would also be economically acceptable, while AES/modified LESA 3 would be "a disastrous selection" — together, the two phases would cost a total of about $20 billion. 

The retired NASA manager ended his paper by broadly assessing the state of NASA lunar planning. He noted that, of the $26 million allotted to planning for advanced piloted lunar systems in the Fiscal Year 1965 NASA budget, most was budgeted for examination of inefficient and limited systems such as AES. "Only a trickle," he wrote, was devoted to the study of "more sophisticated and efficient systems." 

NASA and its contractors continued studies of advanced lunar systems throughout the 1960s and into the early 1970s. Studies focused mainly on AES/ALSS-type missions. It was hoped these would fly during the 1970s as part of the Apollo Applications Program (AAP), which became AES's successor shortly after Evans' May 1965 presentation. At the same time, scientific advisory groups advocated for advanced lunar exploration.

Apollo did not, however, imply a long-term national commitment to lunar exploration. Between 1964 and 1968, President Lyndon Baines Johnson repeatedly signaled his support for an Apollo-derived post-Apollo NASA program; lack of support for the program in Congress, however, caused NASA Administrator James Webb to turn the agency's efforts increasingly away from post-Apollo lunar exploration. In addition, the Apollo 1 fire of 27 January 1967, which killed astronauts Gus Grissom, Ed White, and Roger Chaffee, did immeasurable damage to NASA's post-Apollo prospects.  

NASA Administrator James Webb (center) with Vice-President and National Space Council chair Hubert Humphrey (left) and President Lyndon Baines Johnson (right). Image credit: NASA.

In the 1969-1971 period, when NASA Administrator Thomas Paine's Integrated Program Plan (IPP) held sway, the space agency and its contractors studied complex and costly lunar transportation systems (such the Nuclear Shuttle), space stations in lunar orbit, and permanent lunar surface bases. Such plans received no support from the Administration of President Richard Nixon, however, and all IPP planning ceased soon after Paine's resignation in September 1970. 

Despite these setbacks, some features of AAP lunar advance planning found their way into the last three Apollo missions to the Moon (Apollos 15-17). Designated J-class, their technological improvements included heavier lunar surface payloads, enhanced lunar surface mobility, space suits with greater flexibility and endurance, longer lunar surface stay times (up to three days), added lunar surface scientific instruments, a bay full of Moon-pointing scientific sensors in the lunar-orbiting CSM, and a subsatellite ejected into lunar orbit from the CSM.

The image at the top of this post illustrates the course U.S. lunar exploration took after Evans presented his paper. It shows Apollo 17 Commander Eugene Cernan saluting Old Glory in the Taurus-Littrow valley in December 1972. 

Apollo 17 left Earth atop the penultimate Saturn V rocket to fly (the last to fly would launch the Skylab Orbital Workshop, the last vestige of AAP, into low-Earth orbit in May 1973, eight years after Evans' presentation). Apollo 17's jeep-like Lunar Roving Vehicle (just visible behind Cernan) ranged up to 7.6 kilometers from its home base, the LM Challenger (behind flag), during three traverses spanning three days. The only professional scientist to reach the Moon, geologist and Lunar Module Pilot Harrison Schmitt, snapped the picture. 

Source

"Lunar Exploration: What is the Proper Course?" Thomas Evans, Post Apollo Space Exploration, Francis Narin, editor, 1965, pp. 647-661; paper presented at the 11th Annual Meeting of the American Astronautical Society in Chicago, Illinois, May 3-6, 1965.

More Information

Apollo Science and Sites: The Sonett Report (1963)

Apollo Extension System Flight Mission Assignment Plan (1965)

"Without Hiatus": The Apollo Applications Program in June 1966

"Assuming Everything Goes Perfectly Well in the Apollo Program. . ." (1967)

Think Big: A 1970 Flight Schedule for NASA's 1969 Integrated Program Plan