The second Boeing X-37B Orbital Test Vehicle (OTV) landed at Vandenberg Air Force Base at 5:48 a.m. Pacific time on Saturday, marking the successful completion of its first flight. Being developed for the Rapid Capabilities Office of the U.S. Air Force, the X-37B is intended to demonstrate the capabilities of reusable unmanned spacecraft in the wake of the retirement of the Space Shuttle fleet.
The successful first flight of OTV-2 comes on the back of the first flight of the first X-37B, OTV-1, in 2010, which saw that craft become the United States’ first unmanned vehicle to return from space and land on its own. Whereas that mission lasted 220 days, the OTV-2 mission was extended to 469 days and involved the testing of additional capabilities.
Although it relies on the same lifting body design of the Space Shuttle and features a similar landing profile, the X-37B is around a quarter the size. It is also built using lighter composite structures rather than traditional aluminum and sees the debut of a new generation of high-temperature wing leading-edge tiles known as toughened uni-piece fibrous refractory oxidation-resistant ceramic (TUFROC) tiles.
Combining the best attributes of an aircraft and a spacecraft, the X-35B is designed to be launched like a satellite and land like an airplane. There are no hydraulics onboard and all avionics are designed to automate all de-orbit and landing functions. The X-37B OTV is designed to operate in low-earth orbit (LEO) at an altitude of 110 to 500 miles (177 to 805 km) above the Earth at a speed of around 17,500 mph (28,164 km/h).
To further demonstrate the affordability and reliability of the X-37B, a second launch of OTV-1 is planned for later this year.