Cape Canaveral: A top-secret mini-space shuttle has blasted off from Cape Canaveral in the US.
The Air Force launched the unmanned spacecraft today aboard an Atlas V rocket.
It`s the second flight for this original X-37B spaceplane. It circled the planet for seven months in 2010. A second X-37B spacecraft spent more than a year in orbit.
These mystery machines are about one-quarter the size of NASA`s old space shuttles, and they can land automatically on a runway.
The military isn`t saying much, if anything, about this new secret mission. But one scientific observer, Harvard University`s Jonathan McDowell of the Harvard-Smithsonian Center for Astrophysics, speculates the spaceplane is carrying sensors designed for spying.
The two previous secret flights were in orbits roughly 200 miles (321 kilometres) high.