GRAHAM WARWICK / WASHINGTON DC
Lockheed Martin has conducted high-speed wind tunnel testing of its pad abort demonstration (PAD) vehicle, which is intended to test crew escape systems for NASA's planned Orbital Space Plane (OSP). Tests proved the vehicle is stable under the manoeuvring required to escape a catastrophic booster failure on the launch pad, the company says.
The demonstrator is designed to accommodate alternative propulsion systems and adapt to different OSP configurations.
For the first flight in mid-2005, the vehicle will consist of a representative crew escape module mounted on a pusher propulsion module, with a flared structure attached to the propulsion module providing aerodynamic stability. Instrumented mannequins will measure loads on the crew.
After a 6-9g powered phase lasting 5s, and simulating separation from the launch vehicle after a pad mishap, the PAD will coast from Mach 0.9 to M0.3 when the recovery system will deploy.
Aerodynamic stability will ensure safe transition to a parachute recovery without the need for complex attitude-control systems, says Lockheed Martin.
Meanwhile, NASA administrator Sean O'Keefe has tried to defuse criticism of plans to accelerate the OSP, to provide an International Space Station crew rescue capability by 2008, by assuring Congress there will be "ample time" for lawmakers to review the programme.
Although a draft request for proposals has just been released, NASA does not plan to select a team to develop and build the OSP before August next year.
Source: Flight International
