At the crossroads, tryin' to flag a ride

摘要

The US risks losing its edge in human space exploration and faces the humbling prospect of relying on outsiders to put its astronauts into space. Battles are brewing over the direction the agency should take, and decisions made in the next few months may shape US spaceflight for decades to come. So where does NASA's future lie? In July NASA will celebrate the 40th anniversary of humanity's first steps on the moon. But 2009 sees confusion over the agency's next "giant leaps", and its planned return to the moon is in the balance: the space shuttle fleet is set to retire in 2010, although the shuttles' troubled successor will not be ready until 2015 at the earliest and many space commentators, and even some NASA employees, want to scrap it and start over.