The Boeing X-37 is a demonstration spaceplane that is intended to test future launch technologies while in orbit and during atmospheric reentry. It is a reusable robotic spacecraft that is a 120%-scaled derivative of the X-40A. In 1999, NASA selected the Boeing Integrated Defense Systems to design and develop the vehicle. It will be built by the California branch of Boeing's Phantom Works.
The X-37 was transferred from NASA to the Defense Advanced Research Projects Agency on September 13, 2004. The program has become a classified project, though it is not known whether DARPA will maintain this status for the project. NASA's spaceflight program will be centered around the Crew Exploration Vehicle, while DARPA will promote the X-37 as part of the independent space policy which the Department of Defense has pursued since the Challenger disaster.
This vehicle has the potential to become America's first operational military space plane, after the cancellation of Dyna-Soar. It is expected to operate in a velocity range of up to Mach 25. Among the technologies to be demonstrated with the X-37 are improved thermal protection systems, avionics, and an advanced airframe. The on-board engine is the Rocketdyne AR-2/3, which is fueled by Hydrogen Peroxide and JP-8.
The X-37 was originally designed to be carried into orbit in the space shuttle cargo bay, but underwent redesign for launch on a Delta IV or comparable rocket, when it was determined a shuttle flight would be uneconomical.
The vehicle currently under construction is an atmospheric drop test vehicle. It has no propulsion system, and the thermal protection system tiles are fake; made of foam, not ceramic. The follow up orbital vehicle, if constructed, will likely be classified. It may be referred to under a different X-plane designation, since it would be at that time a DARPA project.
On September 2 2004 it was reported that for its initial atmospheric drop tests the X-37 would be launched from the Scaled Composites White Knight, a high-altitude research aircraft better known for launching Scaled's SpaceShipOne.
Specifications (Boeing X-37)
- Crew: none
- Length: 27 ft 6 in (8.38 m)
- Wingspan: 15 ft 0 in (4.57 m)
- Height: ft in ( m)
- Wing area: ft² ( m²)
- Empty: lb ( kg)
- Loaded: 12,000 lb (5,455 kg)
- Maximum takeoff: lb ( kg)
- Powerplant: initially none, follow up vehicle may have 1× Rocketdyne AR2-3, 29.3 kN (6,582 lbf) thrust (vacuum)
- Maximum speed: mph ( km/h)
- Range: miles ( km)
- Service ceiling: ft ( m)
- Rate of climb: ft/min ( m/min)
- Wing loading: lb/ft² ( kg/m²)
Related development: Boeing X-40