Though Boeing and the USAF are quite mum on the details and future applications for X-37B, the program's precursor is making its public display debut this week at the National Space Symposium in Colorado Springs.
The so-called Approach and Landing Test Vehicle (ALTV) was used in 2006 for drop tests from the White Knight to validate guidance and landing. The ALTV was released during three flight tests at altitudes higher than 30,000 ft. and landed at Edwards AFB, Calif.
This work fed into the X-37B program. X-37B was the first unmanned vehicle to conduct operations in space and return to Earth autonomously. X-37B is about one-quarter the size of the Space Shuttle, and it is intended to allow the Air Force to experiment with generating "sorties," or quick turnaround missions, in space.