What it was: An April 1971 study by North American Rockwell, commissioned by NASA, on putting an eight-astronaut space station in polar orbit around the Moon.
Details: There was a short period of time prior to NASA settling on the Integrated Program Plan when some within that organization advocated a more conservative “space stations everywhere” program instead. A combination of NASA administrator Thomas Paine’s insistence on being bold and Spiro Agnew’s enthusiasm for Mars got the focus shifted to the Red Planet, but the space agency did its due diligence and took a look at the suggested stations in the context of the IPP.
From the standpoint of the 21st century, the most unusual of of these was a space station around the Moon, plainly dubbed the Orbiting Lunar Station, or OLS for short. North American Rockwell got the contract to flesh out the idea and dropped the result on NASA desks in April of 1971, just as Apollo 13 was gripping the world.
NASA’s basic intention was that the orbiting station would have several purposes. Scientific study of the Moon from orbit was one, and so was a supporting role for a surface base—communications with the Far Side, for example, or serving as an emergency shelter, or as a command station for remote rovers (thus alleviating the roughly 2.5 second round-trip delay between the Earth and the Moon). There was also a requirement to use the station for astronomy, including an intriguing suggestion to perform high-resolution X-ray astronomy using the edge of the Moon as an occulting edge, and the idea that the station would serve as an excellent test bed for the systems that would be used in the orbiting command centers that would probably feature during interplanetary missions.
What North American Rockwell presented was a station that would have been launched on a Saturn INT-21 (essentially a Saturn V without its upper stage, similar to what was used to launch Skylab) or in the cargo bay of the then-conceptual Shuttle that NASA was working on. After being checked out in LEO by a crew which would return to Earth, the unmanned OLS would be sent into lunar orbit using a Nuclear Shuttle, and then the first eight-astronaut expedition to the station would be sent using another. The vagaries of the Moon’s orbit around the Earth suggested a mission every 109 days to the station, with North American Rockwell arbitrarily deciding to swap half the crew out each time. After ten years, the OLS would be decommissioned.
As to where the astronauts were going, exactly, North American Rockwell came up with two possibilities. One was a purpose-built station, to which they specifically assigned the name OLS, while the alternative was a refit of a modular station originally built for Earth-orbital activities, which they dubbed the MSS. The end result was functionally the same, however, so for the purpose of simplicity we’ll focus on the OLS.
The station would have been built around a cylindrical core module 60.83 feet long and 27 feet in diameter (18.5 × 8.2 meters). It would have four receptive docking ports around its side, and one “neuter” port on each end, all intended for docking visiting ships or expansion with further modules later. Within were six decks, four of which were pressurized for human habitation. Access between these decks was provided by a series of circular openings on the station’s long axis; the exception was between decks 2 and 3, which were connected by a hatch that could be sealed off in the case of emergency.
One of the end ports would be used to attach a 33.42′- (10.2 meter-) long power module, which would unfurl four solar arrays totaling 10,000 square feet (929 square meters) hooked to regenerative fuel cells for storage, while one of the four receptive ports would house experiments that needed “a clear field of view” (the astronomy experiments, one presumes) and a bay for storing and repairing satellites the station would drop into other lunar orbits. Altogether it would have a dry mass of 107,745 pounds (48.75 tons); compared to other stations it would have been intermediate in size to the larger Skylab and the smaller Salyut-7.
The core module would also have a radiation shelter on the second deck, containing a secondary control room, backup galley, and toilet, protected by the stations 16,000 pounds of water (roughly 7250 liters) stored in a jacket around the shelter. The water was also used by the thermal radiators to deal with what NAR termed “the significantly more severe” environment in lunar orbit.
The OLS’s ten-year lifespan was specifically targeted to the 1980s, giving some idea of how long North American Rockwell though it would take to get it up and running.
What happened to make it fail: Like the rest of the IPP with which it was associated (with the partial exception of the Space Shuttle) the OLS ran into the avalanche that was the early 1970s. As well as major budget cuts and indifference on the part of the government and the American public toward space ventures, it had the additional problem of no high-level advocate. NASA administrator Tom Paine in particular was critical of the “stations everywhere” approach and preferred Wernher von Braun‘s more audacious Mars mission. There it would be only a minor part, if it existed at all.
What was necessary for it to succeed: You’ve got to start somewhere, begin with an administrator or a “rock star” like von Braun backing it to the full. Then all you have to do is prevent the economic troubles of the 1970s, end the Vietnam War, and somehow get one of the President or the general public on side. Piece of cake.
If you relax the requirement for success to include a lunar station not directly descending from NAR’s study, the situation gets a little easier. The American and Russian space agencies have discussed the possibility of a lunar station as a follow-up to the ISS, and it’s to North American Rockwell’s credit that both have described a setup not too dissimilar from the OLS. Though NASA still seems more interested in an asteroid redirect mission or a Mars mission at the moment, there’s a halfway decent chance that, about sixty years after the fact, the OLS’s descendant will take flight.
Orbiting Lunar Station (OLS) Phase A Feasibility and Definition Study, Vol. V; Space Division North American Rockwell; Downey, California; April 1971.
The Space Shuttle Decision; T.A. Heppenheimer; NASA History Office; Washington, DC; 1999.