A trillion dollars to send astronauts to Mars? If such claims are valid, it's no wonder that the public might waver in its general support for space exploration. But despite the repeated use of this figure in the news media, the actual cost is expected to be much, much less.
Just hours after President Bush announced NASA's new space initiative on Jan. 14, Robert Greenstein, executive director of the liberal Center on Budget and Policy Priorities, told NBC News: "With today's dollars and today's technology, we're probably ultimately talking about half a trillion to a trillion dollars. …" An Associated Press article, meanwhile, suggested that "informal discussions have put the cost of a Mars expedition at nearly $1 trillion." And according to Tom Schatz, president of Citizens Against Government Waste in Washington, "Cost estimates for the new programs range from $550 billion to $1 trillion."
However, engineering cost analysis that has worked in the past suggests that the actual cost of Bush's proposals will be only a fifth to a tenth as great as the frightening numbers being waved around. The slowly mounting NASA allocations, as shown on budget proposals, are in line with these estimates.
The history of wild guesses
It's undeniable that spaceflight costs money — about $15 billion a year for NASA and $20 billion more for the Pentagon's satellites and rockets. New projects involving humans with more advanced spaceships will cost even more. For many people, that already costs too much, and for others, any additional spending — even Bush's recommendation for an additional billion dollars for NASA over the next five years — is intolerable.
The origin of a super-high price tag for sending humans to Mars can be traced way back to the mid-1960s. At that time, a number of scientists, none with direct experience in space engineering, issued what space workers affectionately like to call SWAGs ("Scientific Wild-Ass Guesses") on the expenses. These were based on strained analogies to what they thought they knew about Apollo.
In 1965, D. F. Hornig, science adviser to President Johnson, told a Senate committee: "If we compare the probable scale and technical difficulties of a manned Mars expedition with Apollo, it is hard to conclude that its probable cost could be much less than perhaps five times that of Apollo — that is, of the order of $100 billion."
The same year, Abraham Hyatt wrote in Astronautics and Aeronautics magazine that "the cost of a manned Mars expedition is estimated at $75.2 billion [three Apollos] spread over a 15-year period.”
Adjusting the price tag
But based on studies conducted by Charles S. Sheldon II (a true unsung genius of space policy analysis) in the early 1970s at the Science Policy Research Division of the Library of Congress' Congressional Research Service, a very different picture emerged: "If one assumes a [space] program will have other reasons to develop a reusable shuttle, a versatile space tug and a universal space station module (all to serve many Earth orbital economic, military and scientific purposes) then even the total costs of developing a Mars expedition become far different from the kind of $100 billion figure which has been common to the literature.
"People tend to overlook how much of the Apollo costs were associated with building a basic U.S. space capability rather than just going to the moon per se," Sheldon continued. "One might think of a Mars expedition of the type discussed as much closer to the order of magnitude of $10 billion rather than the $25 to $35 billion of Apollo or the $100 billion postulated so often for Mars."
The logic of this view was in line with the estimates of other experienced space managers in that period. For example, Convair missile manager Krafft Ehricke also had pointed out: “One important reason for the relatively low cost of developing a manned planetary capability is that... many of the preparations are identical with those required to attain a better orbital and lunar capability.”
In the late 1970's, analysts in the British Interplanetary Society, based in London, did their own cost studies for a joint U.S.-European Mars expedition. Engineer Robert Parkinson reported: “Given the right circumstances it is actually cheaper to send men than to try to do the same thing with dozens of robot expeditions."
How much is one Apollo?
These estimates and later ones tried to avoid long-term inflation issues by using a cost unit called "one Apollo," the amount spent during the moon race. One Apollo was equal to $25 billion in 1970, and adjusted for inflation is the equivalent of $56 billion in 1982 and about $100 billion today.
The Mars costs can be compared in other ways. As a percentage of contemporary gross national product, Apollo cost 2.8 percent, and the shuttle and a program to send humans to Mars were costed at one-sixth of that. As a per capita expense, both the shuttle and a Mars expedition cost about one-fourth of the expense for Apollo.
Yet science journalist Gregg Easterbrook insists that $800 billion or more is a likely number. Writing for The New Republic, he states: "So far all money numbers announced for the Bush plan seem complete nonsense, if not outright dishonesty. ... The people around Bush, and at the top of NASA, ... apparently are either astonishingly ill-informed and naïve, or are handing out phony numbers for political purposes, to get the foot in the door for far larger sums later."
Most space historians would say it’s Easterbrook who is peddling nonsense. When he started with a 1989 figure of $400 billion for the elder President Bush's Space Exploration Initiative, Easterbrook wrongly assumed it was only for a Mars mission, and then rounded up for inflation to arrive at a figure of $600 billion. A lunar base would cost another $400 billion, equaling the magic $1 trillion. But he counted the moon base twice, it turns out.
According to space historian Dennis Powell, this figure "apparently derives from the half-trillion dollars NASA (kicking up its heels in delight) estimated would be the cost of a gold-plated moon base and trip to Mars when George H.W. Bush proposed it in 1989. Someone, somewhere, applied some goofy mathematical spinning to the price of NASA's 1989 wish list and came up with the $1 trillion figure. It's worth remembering that NASA didn't get its wish list."
Removing the gold plating
Space historian David Portree, in a book on NASA's many different plans for Mars, pointed out that this 1989 plan "was over-costed by a considerable amount." The original estimates already included a 55 percent reserve, Portree said.
The cost of a permanent moon base in that 1989 plan, including the 55 percent "cushion," would have been $100 billion in constant 1991 dollars between 1991 and 2001. The Mars expedition would have cost an additional $158 billion between 1991 and 2016, based on the same stipulations. Thus, achieving a return to the moon to stay and a mission to Mars would have cost a total of $258 billion, of which 55 percent ($141 billion) was cushion and $117 billion was the expected actual cost.
Even that was a "gold-plated" plan. As with previous studies, Portee explained, this team "opted for a 'brute-force' approach to piloted Mars exploration, requiring such big-ticket items as heavy-lift rockets that dwarfed the old Saturn V, nuclear-thermal propulsion and a lunar outpost."
But this approach never gained much support and did long-term damage to the entire concept.
"Proposing it repeatedly over the past 30 years has succeeded mainly in ingraining the belief that Mars exploration must be exorbitantly expensive," Portree said. "Subsequent NASA Mars plans have sought to cleverly apply technologies new and old to reduce cost and tighten the schedule. They have begun the slow process of expunging the perception that a Mars mission must be conducted in a costly way."
Depending on strategies still to be worked out, the two big-ticket items in the president’s plan — the new space capsule and return to the moon, followed by development of human interplanetary flight — each will cost significantly less than “one Apollo” each.
But that's not what the public is hearing. Powell complains: "The most misleading of the arguments is the one having to do with cost. The number being batted around — $1 trillion — was apparently pulled by someone from the thin vacuum of space. It is a made-up number. A fabrication."
Bush’s new space plan certainly deserves to be debated. And it won’t be cheap. But any discussions that are based on flawed data and outright fantasies are worthless.