How much does the international space station cost? Because we're talking about government work here, it's a tricky question to answer. But the estimates start at roughly $35 billion — which is what the Government Accountability Office says Congress has appropriated for the station project since 1985 (PDF file) — and rise to $100 billion, which is roughly what the GAO said would be the total cost "to develop, assemble and operate" the station (PDF file).
The figures vary because there are different ways of figuring in such factors as the expense of shuttle flights in support of the station, and the costs incurred during the design phase for Space Station Freedom, the all-American precursor to the international space station. Naturally, NASA's cost estimates tend to be lower than the GAO's.
Like most government projects, the costs have escalated as the years went by. When President Reagan first proposed Space Station Freedom in 1984, the projected price tag was $8 billion. An estimated $11.2 billion was spent on the Freedom project before its cancellation in 1993 by President Clinton. At the time, Clinton said the international station would cost $17.4 billion.
Are American taxpayers getting their money's worth, at $35 billion or $100 billion? For comparison's sake, here are the estimated price tags for some other "big science" projects:
- $365 million for the Laser Interferometry Gravitational-Wave Observatory, two facilities in Louisiana and Washington state designed to sense faint perturbations caused by gravity waves. Such waves are predicted by Einstein's general theory of relativity but have not yet been detected.
- $800 million for the twin Mars Exploration Rovers, both of which are still exploring the Red Planet more than two and a half years since their landings. The $800 million was budgeted for the first 90 days of the missions, but NASA has granted extensions at an additional cost amounting to just a fraction of that amount.
- $3.4 billion for the National Ignition Facility, a California experiment that would use powerful lasers to create the conditions for inertial confinement fusion. The facility is due to be completed by 2010, but critics fear that the cost may rise to $5 billion by then.
- $8 billion for the Large Hadron Collider, a European particle accelerator measuring 17 miles (27 kilometers) in circumference. The LHC is due to begin operation in 2007, becoming the world's most powerful collider.
- $8.25 billion to $11 billion for the Superconducting Super Collider, a particle accelerator in Texas, measuring 54 miles (87 kilometers) in circumference, that was canceled in 1993 after $2 billion was spent. The estimates were for the total construction cost as of the time of the controversial project's cancellation.
- $13 billion for the ITER experimental fusion project in France, scheduled to begin operations in 2016 and lead to the development of a viable magnetic confinement fusion reactor by 2050. The international project includes provisions for a research facility in Japan as part of the agreement to place the reactor in Europe.
- $55 billion to $100 billion for a "Mars Semi-Direct" campaign leading to human missions to Mars. The lower figure is the one that was cited by NASA in the mid-1990s as its reference mission for a 20-year push to Mars. Although NASA has begun discussing manned trips to Mars as an eventual goal, the agency has not yet set forth a revised reference mission as part of its "Vision for Space Exploration."
- $104 billion for NASA's campaign leading to human missions to the moon, as laid out in the Vision for Space Exploration. This project involves the development of a new spacecraft system for lunar trips — and the projected expense has led NASA to scale back the scope of its $100 billion international space station project.