Sending astronauts to asteroids
In a speech outlining his plans for the U.S. space program, President Barack Obama said, "We'll start by sending astronauts to an asteroid for the first time in history. Four months after that statement, the details are still sketchy, as Congress continues to debate the financing and overall direction of U.S. space policy. But experts say a human mission to an asteroid could become NASA's next great challenge – a deep space journey that compares to the moon missions of the 1960s and 1970s, It could even be seen as a steppingstone to Mars.
NASA and contractor Lockheed Martin have begun to design and build a prototype of Orion, a capsule that could be used to send astronauts into deep space. A propulsion module and possibly extra crew space could be added, said Thomas Jones, a former shuttle astronaut and space consultant.
Tens of thousands of asteroids orbit the sun in an "asteroid belt" beyond Mars. But a human mission to an asteroid would focus on one that comes closer to Earth.
Why go to an asteroid?
Big asteroids have hit Earth before — this may be what caused dinosaurs to become extinct. Another big one could wipe out human civilization. This mission would give NASA better information on how to save Earth from the impact of another big one (kind of like Armegeddon, the fun but scientifically inaccurate film with an asteroid plot).
The six-month mission could be a good dress rehearsal for a mission to Mars. It's challenging, but not as far and not as complicated because of the asteroid's limited gravity.
Asteroids hold keys to understanding the origins of the solar system. Astronauts could collect many samples and return them to Earth.
The journey could take six months, said former astronaut Jones. That's a long time to be in the cosmic radiation of space. And the journey home could take weeks, even if there's an emergency. The new spacecraft and a new rocket must be developed with continued funding over several congressional terms and more than one presidential administration.
Sources: NASA, White House, space consultant Thomas Jones.