Published in German in 1952, and in English in 1953, von Braun’s “Mars Project” envisaged a 70-“man” crew making the trip, supported by an army of ground-side engineers. Ten interplanetary spaceships of 3720 tons each would be assembled in orbit and fueled with nitric acid and hydrazine, liquids von Braun thought would be easier to handle than cryogenic hydrogen and oxygen. Earth to orbit service would be provided by a fleet of 46 3-stage reusable “ferry” vessels each with 39 ton payload capacity, with 950 launches required to place the 37,200 tons in orbit. Travel to Mars would be by the usual minimum velocity-change transfer, or about 260 days, and the ten spaceships would spend about 400 days in Mars orbit before returning. Most of the crew would travel to the Mars surface using three “landing boats”, two of which would be expected to return to orbit for the return trip, which would bring back seven of the ten original space ships.
The scale of the proposed enterprise is breathtaking, but far from impossible – von Braun notes the total fuel use by the “ferry” vessels, each of which would burn 5500 tons of propellent on each launch, would be just ten times the fuel use by aircraft during the 6-month Berlin airlift. As von Braun puts it
it will be on the grand scale and it will be expensive, but neither the scale nor the expense would seem out of proportion to the capabilities of the expedition or to the results anticipated.
Von Braun’s design for the 6000-ton (at liftoff) 3-stage “ferry” vessels, which placed 66 tons in orbit (including the reusable “ferry” mass) inspired both his later Saturn-V and the Space Shuttle. The Saturn V, at 3000 ton liftoff weight, placed 118 tons in orbit; Shuttle, with 1500 ton liftoff weight, puts over 120 tons into orbit (including the 100-ton orbiter), but has a lower payload capacity than von Braun’s proposed “ferry” (von Braun’s orbiter weight estimate was just 22 tons). All three are what would now be considered “heavy-lift” vehicles.
While the shuttle proceeded as we well know, other elements of von Braun’s plan made progress, or rather retrogressed, only on paper. He makes only brief mention of a space station, and none at all of the Moon. The Mars Project’s most direct descendent is probably none other than Robert Zubrin’s Mars Direct proposal, which, aside from technology details, differs only in being (A) far smaller in scope (4 people in one or two space ships at a time, not 70 people in 10) and (B) making use of Martian resources for the return trip.
The 1989 Space Exploration Initiative seems to be the source for all the half-trillion dollar cost numbers people bandy around these days. In fact those costs included establishing a lunar base as well; the Mars portion was also much smaller in scope than von Braun’s plan with a single ship and small crew, and differed from Zubrin’s plan mainly in being more cautious on the safety side and not relying on Martian resources for the return.
The space station was likely inspired by von Braun’s concept for a manned station as a staging area, but what we have so far is also much smaller in scale than his vision, and still unfortunately lacking in real purpose.
Von Braun was clearly a huge success with Apollo, so why did the US fail to follow through on his other ideas, producing bare shadows of their seeming potential, and so far nothing real as far as humans to Mars is concerned?
There is another concept for the future of humans in space, one articulated by Gerard O’Neill in his High Frontier. O’Neill saw space as a source of immense resources, particularly the essentially unlimited solar energy, and Mars had little or no place in his vision of the future. His central question was whether a prosperous humanity had any real need to live on a planetary surface at all – given the scale of resources out there, it seemed not. O’Neill’s proposed orbital colonies were of a scale even larger than von Braun’s vision though – not ten’s of thousands of tons, but millions of tons in mass, with tens of thousands of people as residents.
Perhaps it’s just a matter of a vision from 50 years ago having outlived its usefulness. Rather than tackling hugely ambitious, major projects like von Braun’s Mars Project, an O’Neill colony, or even Mars Direct before 2020, the future of US space endeavors looks to be one of many relatively small steps, evolutionary changes over time. In fact that’s basically what we’ve seen through the shuttle and space station era with fleets of ever-improving robotic spacecraft visiting planets, asteroids and comets or just observing the universe. It’s time to apply that small-scale evolutionary approach to human spaceflight, and it seems to me that is exactly what the new vision statement intends.
Why the Moon first? Because it can be done and built up in evolutionary steps from something we’ve done before, with dozens of milestones along the way:
- lunar orbiters: photography and communications
- lunar robotic landers and rovers
- the first human lunar return
- first lunar farside landing
- first visit to lunar poles
- first visit to lunar highlands
- first stay through a lunar night
- longer term stays
- in situ oxygen manufacture, buried asteroid prospecting, metal mining and extraction
- underground habitats
- lunar telescopes
- lunar hotels…
- and much more.
Under the mesmerizing sway of von Braun’s (and now Zubrin’s) focus on Mars, NASA has neglected the Moon almost completely for 32 years; this despite studies since 1980 that have recommended lunar missions. It’s time for that to change, and the new vision statement seems expressly designed to make that happen.