Can they do it? When President Bush announced a plan early this year to send Americans back to the moon – and beyond, to Mars – skeptics wondered whether NASA, with its decades of tread-water budgets and institutional inertia, was up to the job. Equally important, though, is a companion question: Is the aerospace industry up to the job? Boeing, for one, says it is eager to take up the challenge, and refers to decades of expertise in running enormously complex space ventures.