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Home | Update | LATEST ISSUE | Gallery | FR Profile | Datafiles | FR 7/98 NASA TESTS X-38 RESCUE VEHICLE by Christopher Hess The re-entry vehicle which landed by parachute in the Californian desert on March 12th is no stranger to the scene. Searching for an economic Crew Rescue Vehicle for the International Space Station NASA has started a series of tests using the technology demonstrator X-38. The design of the X-38 is based on the experimental lifting-body Martin X-24A, which successfully flew for the US Air Force between 1969 an 1971. A completely new design was rejected because of the high development costs, estimated at around two billion US dollars. After evaluating a study researched by the Johnson Space Center in early 1995, NASA opted for the X-38 instead, which should be based on the aerodynamic concept of the X-24A. The new re-entry vehicle will have room for up to seven persons. Its live support equipment will enable a flight time of nine hours after seperation from ISS. Landing is conducted automatically, although the crew has the possibility to switch to secondary systems and to steer both the orbital position and the parachute upon landing. After several successful flights using scale models, NASA started trials with the first full-scale demonstrator (V-131) focusing on the transition from gliding flight to the parachute deployment. A Boeing B-52 bomber carried the X-38 hanging under its wing station to an altitude of 23000 feet and released the lifting-body at a speed of 175 knots (324 km/h). Four seconds after seperation, the parachute, which is 511 square meters large, was activated. After a total flight time of seven minutes and 19 seconds V-131 landed without incident at a descendig rate of 5,2 meters per second and a foward momentum of 61 km/h. Four to six further flights are planned with V-131 which is to be joined by the flight control system equipped V-132 during this summer to examine the flight envelope before deploying the parachute. The introduction into service of the third test vehicle is planned for the next year. During the next 20 flights, one every six to eight weeks, the engineers will gradually increase the release altitude to 50000 feet (15000 meters). All three vehicles are made of aluminium and glas fiber reinforced plastic, weigh 5,8 tons and have a length of 7,8 meters. During the following research phase starting in the year 2000, two further technology demonstrators, 201 and 202, are set to be introduced into the program. With a length of 9,9 meters and a total weight of eight tons they will be around 20 percent larger than the basic design of the X-24A and will have the same dimensions as the later Crew Rescue Vehicle. A Space Shuttle will carry V-201 out of the atmosphere during mission STS-113 at the end of the year 2000. V-201 will then glide towards earth and attempt a safe landing. Since up to 80 percent of the X-38's design are based on available technologies, the costs could be reduced drastically. Therefore the whole test program will cost approximately 280 million US dollars including 150 million dollars for the shuttle flight. Production cost of the four operational CRVs is estimated at around 500 million dollars. Even if the X-38 is designed as an escape system from orbit NASA is already looking at future developments, for example a reusable space transporter that could be launched by systems like the Ariane 5. The European Space Agency ESA is already closely cooperating with NASA in the X-38 program. The German Aerospace Research Center and the German industry is involved in the program. According to current plans the CRV is supposed to be in service in the year 2003, the same date which should see the space station completed. Until then a Russian Soyuz spacecraft will be on rescue duty. From page 40 of FLUG REVUE 7/98 Home | Update | LATEST ISSUE | Gallery | FR Profile | Datafiles | FR 7/98 Copyright 1998 by Motor-Presse Stuttgart. All rights reserved. Last updated June 9, 1998 FLUG REVUE, Ubierstr. 83, 53173 Bonn, Germany