Monday, July 25, 2011

Rethinking Space Exploration

When the shuttle Atlantis touched down in Florida last week, it marked the end of an era for space exploration. Thousands of NASA engineers found themselves unemployed after three decades of a largely successful program. Astronauts scheduled to visit the International Space Station will now be forced to hitch a ride with the Russians. The human space flight program in the United States will soon be handed over to private companies, and anyone willing to pay a few hundred thousand dollars can buy their 15 minutes of space. Is this the beginning of a new era of discovery, or the end of exploration as we know it?

In a 1962 address at Rice University, President John F. Kennedy said "we choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard". Less than 7 years later, the Apollo 11 mission delivered astronauts to the moon and returned them safely to the Earth. There were certainly some scientific contributions of the Apollo program -- astronauts returned samples of the lunar surface, and they set up a reflector that allowed astronomers to measure the distance to the moon with unprecedented accuracy -- but it was driven more by the arms race with the Soviet Union than by science. After all, if the United States could launch a rocket and deliver astronauts to a target nearly 240,000 miles away, that same technology could also be used to deliver a nuclear warhead to Red Square in Moscow. If we accomplished some science along the way -- well, great.

With the cold war now a fading memory, our current leaders have struggled to identify a generational goal for NASA, let alone one that can be accomplished in less than a decade. From the least ambitious circles there have been calls to return to the moon, as if the United States can somehow save itself from imperial decline by reliving the glory days of the past. More ambitious, though arguably suicidal, are the calls to send astronauts to the planet Mars -- apparently for no other reason than to continue providing large subsidies to aerospace contractors. Once outside the protection of the Earth's magnetic field, it would be difficult to avoid a fatal dose of radiation from solar flares during the 450-day round trip. With the Sun gradually becoming more active in its 11-year cycle, such a mission cannot be scheduled for the coming decade. So the two sides struck a compromise: let's send astronauts to an asteroid.

Right on cue, last week NASA's Dawn probe beamed back images of Vesta, one of the largest asteroids in the solar system. No, this is not one of the asteroids on a collision course with our planet, and there are no plans to revive the shuttle program and send retired astronauts on a mission to blow it up. Vesta is much smaller than the moon, but much closer than Mars, so by sending people there we can relive our glory days and continue to provide large subsidies to aerospace contractors, probably without killing any astronauts and almost certainly without making any accidental contributions to science. All of this at a time when funding for the National Science Foundation has been declining in real terms for years, NASA's next generation space telescope is on the chopping block, and the nation is about to go bankrupt.

At the end of the shuttle program, the future of space exploration is up in the air. There are more harmful ways to spend money than using it to send people into space, but there are also more productive ways to spend that money. If science is the purpose, there is much more we can do without ever leaving the surface of our planet.