WORKERS ASSEMBLING EXPERIMENTAL PLANE.

Byline: Jim Skeen Staff Writer

PALMDALE - Two dozen Boeing workers in Palmdale are putting together an experimental unmanned aircraft that will test technologies that could be used on America's next generation of spacecraft.

In a building at Air Force Plant 42, the workers are assembling the X-37, a computer-controlled craft that will test advanced materials and control systems aimed at flight without human intervention.

Slightly over 27 feet long, the X-37 will be carried aloft by a modified B-52H and dropped at altitudes of up to 43,000 feet in tests slated to begin either late this year or in early 2005 at Edwards Air Force Base.

The program is aimed at advancing a number of technologies that could be used in future spacecraft, including new thermal protection systems, composite materials and advanced navigation and control systems.

``The various technologies we are maturing would have application to any re-entry vehicle other than a capsule like in the Apollo program,'' said Carlos Paez, Boeing's X-37 chief systems engineer.

The flight tests will be conducted by NASA's Dryden Flight Research Center at Edwards. A total of five flights are planned, with a top altitude of 43,000 feet and a top speed of roughly 490 mph.

The X-37 initially was funded under a 1999 $173 million contract with the costs being shared by the National Aeronautics and Space Administration, Boeing and the Air Force. The Air Force later dropped out of the program.

In November, NASA awarded a $301 million contract to Boeing's Phantom Works division to continue construction of the X-37 and for the development of a second X-37 capable of staying in orbit for up to 270 days after being launched atop a space booster rocket.

The future of the second, more capable X-37 vehicle, however, is in doubt. NASA is committed to seeing the first X-37 through the testing, but whether the second vehicle is built will depend on whether NASA determines it fits in with the president's initiative to return to the moon.

In the meantime, developmental work on the orbital vehicle will continue through September, NASA spokeswoman Kim Newton said.

The second X-37 is aimed at advancing technologies such as rendezvous systems, to allow spacecraft to join with the International Space Station or other spacecraft; autonomous orbital flight systems; and re-entry and landing systems.

The second X-37 would also serve as a research platform, carrying equipment for weather and atmosphere observation.

Last summer, the program reached a major milestone when the first X-37's airframe went through a series of tests at Boeing's Huntington Beach plant to verify it could handle the strains it will face in flight. After passing those tests, the airframe was sent back to Palmdale to begin the final assembly process.

``The action has shifted from Huntington Beach to Palmdale,'' Paez said. ``All the action is in Palmdale.''

The X-37 is being assembled in Palmdale by a small cadre of about two dozen workers.

The X-37 will be tightly packed with equipment - electronic subsystems, some 390 wiring harnesses and a flight termination system packing a parachute.

``They have got lots of parts to assemble in a very confined space,'' Paez said. ``You have to time who gets in first, who gets in second.''

Plans call for shipping the X-37 from Palmdale to Edwards in mid-August. The testing will begin on the ground with taxi tests to ensure the vehicle can steer and brake on its own.

In the fall, there will be a readiness review involving not only Boeing and NASA Dryden personnel, but independent observers who will help determine whether the craft is ready for flight.

At Dryden, workers will begin preparing the B-52H mothership for the flight tests after it returns this month from a maintenance inspection in Louisiana. The aircraft will be fitted with a pylon, which will be used to carry the X-37 aloft.

Prior to the X-37 missions, Dryden will be conducting tests this summer with an X-37 mock-up to ensure the proper operation of a drogue chute system. The drogue chute will be used to make sure the unmanned craft does not collide with the mothership when it is released.

The X-37 was one of three X-plane projects launched during the Clinton administration to test technologies for future spacecraft. The other two, X-33 and X-34, were canceled after encountering technical woes and cost overruns.

``This is the only one still surviving,'' Paez said. ``Hopefully nobody kills it.''

Jim Skeen, [phone]

james.skeen(at)dailynews.com!dl

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Photo:

An artist's illustration of the X-37 shows the unmanned craft in flight.