Mars Expedition 1969: NASA’s Waterloo (Integrated Program Plan, Part I)

A cutaway view of the Planetary Mission Module (centre) and Mars Expedition Module (right) on top of the Nuclear Shuttle (fully visible on the second ship in the background). Public domain image from the Marshall Space Flight Center, NASA. Click for a larger view.

What it was: NASA’s follow-up to the Apollo program. A manned mission to Mars would have been launched in November 1981, brought twelve men to Mars—six of them landing—and then returned to Earth in August of 1983 (with a flyby of Venus along the return route). There would be two more manned missions by the end of 1985, and a manned base by the middle of 1987.

Details: Neil Armstrong stepped onto the Moon on July 21, 1969 and the obvious next question was “Now what?”

NASA had been answering it intermittently for years prior to this but now they got down to business. In particular, while they supported the Apollo Applications Project they were not content to stick to those missions’ main goal: to find out new things to do with the hardware they had already developed. Quite reasonably they decided that they needed to carry onwards and upwards with their engineering. Not only was a manned mission to Mars the obvious next step from an exploratory standpoint, it had the advantage of requiring that they move beyond Apollo equipment.

To that end they turned once again to Wernher von Braun. This was the culmination of his life dream: he’d published a Mars program in 1948, made a splash with the variant of it published in Collier’s in 1954, come up with another smaller expedition in 1956, and then sponsored the so-called EMPIRE and UMPIRE studies in 1962-64. On August 4, 1969 he made a presentation of what would be his final Mars proposal to the Space Task Group (STG), chaired by Vice President Spiro Agnew.

The mission was to be the penultimate part of a two-decade effort, the Integrated Program Plan, which could really be thought of as “Apollo 2.0”: another vast effort with an end goal, designed to replace the one that had just finished. As such it was part of an integrated whole that developed orbital operations into a finely tuned science, first by practicing with the Apollo Applications Program space stations and lunar base. One of the tools was to be a new space-only booster based on NERVA—which is to say, the first ever nuclear thermal rocket. This piece of equipment, dubbed the Nuclear Shuttle, was intermediate in mass between the second and third stages of a Saturn V, and had a higher specific impulse than any rocket ever flown.

Individual Nuclear Shuttles would be fueled in orbit with liquid hydrogen and used to push men and cargo to the Moon, then the empties returned to Earth orbit when they could be refueled and used again—up to ten times in all. Regular Saturn V launches would occur all through the early to mid-70s, building a space station and generally preparing the necessary infrastructure to be a “gas station”.

Meanwhile the other necessary equipment would be tested as part of an Apollo Moon base (basically a revival of the ALSS Lunar Base, which had been cancelled when new Saturn V production went into hiatus). There would be tests of the Nuclear Shuttle by the end of 1977, and 25 men living on the Moon by 1982.

With all that shaken out, the Mars mission would begin on November 12, 1981 with two ships launched on a Mars-bound a trajectory from low-Earth orbit. Each would consist of three Nuclear Shuttles strapped in tandem and a Mars craft made up of a Planetary Mission Module (PMM) habitation section and a Mars Excursion Module (MEM) lander mated to the tip of the one in the centre. The two side Shuttles would get the centre one and its payload up to speed, then peel loose and re-enter Earth orbit for reuse, while the two diminished mission craft would carry on their way.

There were two because the mission had the unique profile of backing itself up. Strictly speaking only one would be necessary for the mission, but the second would fly in formation to be a lifeboat in the case something went horribly wrong on the first—and the first served the same purpose for the second.

This kind of redundancy was necessary because the mission’s twelve crew were going to be away a long time. They’d arrive at Mars on August 9, 1982, stay there for almost three months, and then return to Earth for August 14, 1983: 640 days in all. In theory you wanted to minimize the weight of what you sent, but no margin for error meant nothing could go wrong without endangering the whole mission. NASA had always operated on the principle that you needed something to work with in case of an emergency, a principle that would prove its worth a few months after von Braun’s presentation when one whole side blew off of Apollo 13’s CSM and the astronauts on board were able to ride the excess margins back to Earth. Away from Earth for far longer than any space mission flown to that point, the Mars expedition would get its margin by literally flying two missions at once.

While at Mars six astronauts would stay aboard the PMM and Nuclear Shuttle combinations, flying in an elliptical orbit (a clever innovation by von Braun which made docking harder but cut the mass needed for the mission in half). After a remote sampler determined that it was safe to descend, six more astronauts would go to the surface in two groups of three aboard the Mars Expedition Modules, a capsule derived from the cone-shaped Apollo Command Module. They would slow down in what had only recently been discovered to be Mars’ very thin atmosphere by combination of a parachute, a ballute (a balloon-shaped inflatable parachute that works well at low atmospheric densities), and finally retrorockets starting three kilometers up.

Cutaway view of a MEM lander. Public Domain image from NASA’s Humans to Mars: Fifty Years of Mission Planning, 1950-2000. Click for a larger view.

A MEM could support its crew on the ground for up to sixty days, then its upper stage could climb back into orbit for rendezvous with the PMMs and Nuclear Shuttles. The latter would then fire up one more time and start the long journey back to Earth on 28 October, 1982.

The mission was not quite done, however. Their trajectory would take them back inside Earth’s orbit on a flyby of Venus on February 12, 1983. While this was a second opportunity for scientific study, it was primarily a speed-shedding maneuver. Four probes would be dropped on the way by.

Having got the right trajectory and speed, the two Mars craft would pull into Earth orbit where they would dock with the space station (while not the Orbiting Quarantine Facility, which was proposed several years later, it would serve the same purpose). From there they would be picked up by the Space Shuttle for the last leg of the journey home. If for whatever reason the space station didn’t exist or wouldn’t be suitable for this, the mission could be designed instead with an Apollo-style command module would let the crew splashdown directly to Earth.

Note that four of the Nuclear Shuttles had returned to LEO near the start of the mission; now the last two had done the same and so had their associated Mars craft. Only the MEMs would have been used up. Accordingly the ships would be refurbished and sent out again in 1986. Meanwhile, a second pair of ships would have been launched early in 1983, and on return be re-launched in 1988. By mid-1989, the intention was to have a 48-man semi-permanent base on Mars.

Bearing in mind that the proposal was part of a larger manned space effort including the Space Shuttle and a Moon base, the total cost of NASA’s programs was estimated about US$7 billion per year through at 1976 and $8 to 10 billion for the few years after that. The Space Task Group accepted von Braun’s Mars proposal and the NASA Integrated Program Plan as a whole, and passed it on to President Nixon on September 15, 1969.

What happened to make it fail: There was an utter disconnect between what NASA thought they should get in funding and what everyone else in the government was willing to give them. Even the Space Task Group was uneasy about the von Braun plan and offered two decompressed (and cheaper) versions of it—one where the Mars landing didn’t take place until 1986 and another where the landing was the goal but there was no set date for it. They still underestimated the opposition they would face.

Mariner 7 flew by Mars the day after von Braun made his presentation to the Space Task Group, and appeared to back up what Mariners 4 and 6 had shown previously: that Mars was a dead world, cratered not overly different from the Moon. We now know that by bad luck these missions happened to photograph the most inhospitable parts of Mars rather than the (slightly) more Earth-like northern Hemisphere, but that realization was in the future. Initial jubilation over Apollo 11 faded within a few months in favour of hard questions about why men had to go to Mars in light of what had been learned.

There was also a strong sense among the public and politicians that the United States had to get its house in order down on Earth. Protests against the Vietnam War were at their height and the country was still reeling from the urban riots of 1968. The Republicans had been voted back into power in the presidency in response (though the Democrats still controlled Congress) and Nixon was to continue the squeeze on the NASA budget that his Democratic predecessor had begun. When his director of the Office of Management and Budget Robert Mayo—an observer on the STG—objected to NASA’s proposal for FY 1971 coming in 29% over the cap he had imposed on them (US$4.5 billion instead of $3.5 billion) he convinced Nixon to put his foot down and NASA’s entire manned space program entered a death spiral.

By the time the dust settled almost all of von Braun and NASA’s programs had been cut. On March 3, 1970 Nixon announced that he’d allow only a truncated Apollo program, one space station (Skylab) and a commitment to the Space Shuttle. NASA would try one more Mars proposal in 1971; Wernher von Braun left NASA in 1972 and died in 1977 even before his proposed mission would have launched.

What was necessary for it to succeed: Almost everything was pointing against a Mars mission being approved in 1969. Public opinion was dubious (a Gallup poll in July 1969 found 53% of Americans against it—as Apollo 11 was going on!), the political interest to explore space was fading away in the Democratic Party as John F. Kennedy receded into the past, and Nixon was struggling with paying for the Vietnam War just as the US economy was sliding into recession. After his presidency various inside sources reported that he had been looking for a way to wrap up Apollo without looking like “The Man Who Killed the Space Program”; ironically, the less-ambitious options included in the STG’s report gave him the loophole he needed to dive through.

One possibility that could have brought about the mission would be a virtual tie in the space race, with the Americans and Russians getting to the Moon in a dead heat or possibly even the Russians getting a man on the Moon first. Under those circumstances the US might have committed to “Space Race, Round 2” and go for Mars. But this is a hard one to get flying, for all that it’s about the closest we’ve ever been to seeing a manned Mars mission. Even if it had been approved how much it would have had to shrink and delay as it rode out the 1973 Oil Crisis and the jittery economic conditions that lasted into the early 1980s is an open question.

Some very nice renders of this mission can be found on the DeviantArt page of Drell-7, AKA Tom Peters.