The X-37B Orbital Test Vehicle is an unmanned space vehicle that will be used by the United States Air Force to explore reusable vehicle technologies in support of long-term space objectives. These objectives include space experimentation, risk reduction, and concept of operations development. Boeing's involvement in the program began in 1999.
The Rapid Capabilities Office of the U.S. Air Force is the customer for the X-37B Orbital Test Vehicle. The program transitioned to the U.S. Air Force in 2004 after earlier funded research efforts by Boeing, NASA and the Defense Advanced Research Projects Agency.
Boeing's Experimental Systems Group, a unit of Boeing Government Space Systems, is the prime contractor for the X-37B Orbital Test Vehicle.
The X-37B is one of the world's newest and most advanced re-entry spacecraft. Designed to operate in low-earth orbit, 110 to 500 miles above the Earth at a nominal speed of about 17,500 miles per hour, the vehicle is the first since the Space Shuttle with the ability to return experiments to Earth for further inspection and analysis.
Because the X-37B can be returned to Earth, reused, and is designed to be highly flexible and maneuverable, its contributions to space exploration will result in making space access more routine, affordable and responsive.
The X-37B features many elements that mark a first in space use. The X-37B is one-fourth the size of the Space Shuttle, and relies upon the same family of lifting body design. It also features a similar landing profile. The vehicle was built using lighter composite structures, rather than traditional aluminum. A new generation of high-temperature wing leading-edge tiles will also debut on the X-37B. These toughened uni-piece fibrous refractory oxidation-resistant ceramic (TUFROC) tiles replace the carbon carbon wing leading edge segments on the Space Shuttle. The X-37B will also use toughened uni-piece fibrous insulation (TUFI) impregnated silica tiles, which are significantly more durable than the first generation tiles used by the Space Shuttle. Advanced conformal reusable insulation (CRI) blankets are used for the first time on the X-37B.
All avionics on the X-37B are designed to automate all de-orbit and landing functions. Additionally, there are no hydraulics onboard the X-37B; flight controls and brakes use electromechanical actuation.
The on-orbit duration of the X-37B will vary based upon mission requirements, but has the ability to perform missions lasting up to 270 days.
The first vehicle, OTV-1, was launched April 22, 2010. The objectives of the first flight were to demonstrate that the X-37B is able to conduct long-duration operations, and to enable scientists to understand the long-term effects on system components, such as the structure and future payloads. The successful first flight included achieving orbit, de-orbiting, and safely landing at Vandenberg Air Force Base. The successful landing and recovery of OTV-1 occurred on Dec. 3, 2010. The second vehicle, OTV-2, was successfully launched on March 5, 2011 and landed successfully and was recovered June 16, 2012 after a 469-day mission. OTV-1 was launched and began its second mission on Dec. 11, 2012, and successfully landed on Oct. 17, 2014 after 674 days on orbit.
For more information, read the X-37B overview.
The X-37B Orbital Test Vehicle was built at several Boeing locations in Southern California, including Huntington Beach, Seal Beach and El Segundo.
The X-37B orbital test vehicle program began in 1999, when Boeing and the National Aeronautics and Space Administration began researching the vehicle concepts. Later, DARPA divided the program into two vehicles, an X-37 approach and landing test vehicle (ALTV) and an X-37 orbital vehicle. The X-37 ALTV was designed to validate flight dynamics and extend the flight envelope beyond the low speed/low altitude tests conducted by NASA from 1998 through 2001 on the X-40A, a sub-scale version of the X-37 developed by Air Force Research Labs. DARPA completed the X-37 ALTV program in September 2006 by successfully executing a series of captive carry and free flight tests from the Scaled Composites White Knight aircraft. The X-37 orbital vehicle envisioned by NASA was never built, but its design formed the basis for the Air Force's X-37B Orbital Test Vehicle program.
||H, 9 feet, 6 inches
L, 29 feet, 3 inches
Wing Span, 14 feet, 11 inches
|Experiment Bay Size
||7 feet by 4 feet
||Low-Earth Orbit, 110 -- 500 miles above Earth