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 Thursday morning, SpaceX successfully launched the X-37B from Cape Canaveral in Florida. Its latest mission is slated to last 270 days, but the Air Force advised in a statement that "the actual duration depends on test objectives, on-orbit vehicle performance and conditions at the landing facility."
In other words, there's no telling how long the thing will be up there.
There's also no telling what the space plane will...