Top-secret space shuttle
US Air Force announces X-37B
The US Air Force says it is going to develop its own variant of NASA’s X-37 – the X-37B Orbital Test Vehicle.
Space plane takes priority
NASA is looking to launch its Lunar Reconnaissance Orbiter and Lunar Crater Observation and Sensing Satellite, but X-37B is scheduled in to use the
Atlas V rocket launcher instead.
First X-37B vehicle launch
X-37B OTV-1 is launched from Cape Canaveral and placed into low-Earth orbit for testing. It suffers a tyre blowout on landing in December.
Second X-37B gets its launch
OTV-2 launches for Earth orbit in 2011 with the remit of testing new space technologies. It ends up in orbit for over 468 days.
Boeing announces scaled-up X-37C
Planned to be between 165 and 180 per cent the size of the X-37B, it would be able to carry up to six passengers.
A third mission blasts off
Six months after OTV-2 lands, OTV-3 launches. It was in orbit for 674 days and 22 hours before landing back on Earth in October 2014.