The first X-38 atmospheric test vehicle, which will be used to demonstrate the concept of a crew-return "lifeboat" for the International Space Station, arrived at NASA Dryden Flight Research Center, Edwards AFB, California on 4 June.

The 7.3m-long vehicle resembles the X-24A lifting body, and will be carried aloft for the first time around 16 June on NASA's Boeing B-52 for a captive carry test. "The timescale for the first free flight looks like late August or early September," says NASA. Initial drops will be made from 25,000ft (7,600m), followed by drops from progressively higher altitudes up to 40,000ft by late 1999. In operation, the successor to the X-38 would detach from the space station, fire a "de-orbit" engine module which would then be jettisoned, glide from orbit unpowered using an all-electric flight-control system, and then deploy a parafoil parachute. The parafoil would be used to control the final descent to landing.

In the early years of the space station, a Russian Soyuz spacecraft will be attached to act as a crew return vehicle. An X-38 type vehicle will be deployed to enable passenger loads of up to six to be returned "sometime after 2000", says NASA. The production vehicle is expected to be anything up to 11m long, but NASA says that the prototype, constructed to a NASA design by Mojave-based Scaled Composites, may be optimised to fulfil the operational role.

Source: Flight International