Pentagon's mysterious spacecraft punches above its weight

IN the Pentagon's vast arsenal there is little quite like it: a super-secret space drone that looks like a miniature version of the space shuttle, but orbits the Earth for months, even years, at a time. Doing what? The Air Force won't say.

On the tarmac, the X-37B, as it is called, looks tiny, standing not much taller than a person. Its …