BBC:
The X-37B is a reusable, unmanned space plane operated by the
US Air Force. It looks like a smaller version of the now
retired space shuttle and launches on top of an Atlas V rocket.
Its missions have been kept secret. The launch on 11 December
from Patrick Air Force Base in Florida was just the third in
the craft's history, with the two previous missions lasting 224
days and 469 days. Speculation abounds over the craft's
missions and capabilities, though the air force's official
description of the X-37B is that it is an "experimental test
program to demonstrate technologies for a reliable, reusable,
unmanned space test platform."
