HUGHES TELECOMMUNICATIONS AND SPACE COMPANY
Electron Dynamics Division
Public Relations Office
P.O. Box 92919 (S10/S323)
Los Angeles, CA 90009
(310) 364-6363
www.hughespace.com		 HSC Logo


HUGHES INSTALLS NEW THERMAL VACUUM CHAMBER FOR XIPS TESTING (photo - XIPS Chamber) (photo - Vacuum Tight)

LOS ANGELES, Jan. 14, 1998 -- Torrance-based Hughes Electron Dynamics Division, a unit of Hughes Electronics Corporation, is investing in the future with a new thermal vacuum chamber that will test electric propulsion for future satellites. The chamber is dedicated to qualification and lifetime testing of the company's newest satellite technology, the xenon ion propulsion system, or XIPS (pronounced "zips"). XIPS replaces much of the chemical fuel used in current satellite designs.

XIPS makes it possible to reduce propellant mass by up to 90 percent in a satellite designed for 12 to 15 years of operation. Less propellant results in reduced cost for launch, an increase in payload, or an increase in satellite lifetime, or any combination of these factors. The new chamber weighs 200,100 pounds and measures 20 feet in diameter by 40 feet in length. More than 20 vendors assisted with the construction and installation of the new $6 million facility, which took one year to construct. The new chamber will be used to test the 25-centimeter XIPS thrusters which are standard on the HS 702 satellite produced by Hughes Space and Communications Company. Of Hughes' current backlog of 36 satellites, 13 will carry XIPS.

"Hughes has been investigating the use of ion propulsion since the early 1960s," said Tim Fong, manager of Hughes Electron Dynamics Division. "Four months ago the Hughes-built PAS-5, an HS 601HP high-power satellite, was launched. With that launch, Hughes became the first company to launch a commercial XIPS system."

The massive chamber contains 30 vacuum pumps, which pump out the xenon emitted during operation of a thruster in the chamber to maintain the vacuum that a satellite experiences in space. The size of the chamber is thus dictated by the number of pumps required to maintain a consistent vacuum, not by the size of the XIPS thruster itself.

"We currently have two qualification thrusters in life test," Fong said. "The first was built in 1995 and has demonstrated more than 8350 hours of continuous operation. The second was built in 1996, and it has demonstrated more than 5700 hours. On a satellite in space, a thruster operates about 1,300 hours per year."

Hughes has also delivered a 30-centimeter XIPS thruster to NASA for use on the New Millennium program's Deep Space 1 spacecraft, scheduled for launch in July.

"At the heart of the XIPS system is xenon," Fong said. "Because it offers the greatest thrust of all the inert gases available for use in satellite propulsion, the efficiencies possible are quite impressive."

The first 25-centimeter XIPS system is scheduled for launch this year on Hughes' first HS 702 satellite. A 13-centimeter version is also available for use on the HS 601HP or "high-power" satellite model.

"Because of this new technology, Hughes is able to offer its customers a variety of capabilities which are not possible with the traditional chemical bipropellant systems," said Donald L. Cromer, president of Hughes Space and Communications Company. "We are proud to be first to market, we are committed to the technology, and we believe XIPS is the key to our continued market leadership."

The on-board XIPS system is used primarily for spacecraft north-south stationkeeping. Small thrusts are required to correct for the tug of solar or lunar gravity and to reposition the satellite in its proper orbit and altitude. A satellite's lifetime -- as well as its launch weight -- is thus determined by the amount of fuel aboard for its thruster system. The 25-centimeter thruster is also capable of being used for orbit raising. Chemical propellant is used to place the satellite into a supersynchronous elliptical transfer orbit, and pre-programmed XIPS maneuvers are used to circularize the orbit and position the satellite in its final orbit.

Thrust is created by accelerating positive xenon ions through a series of gridded electrodes at one end of the thrust chamber. Ions ejected by the Hughes-designed XIPS travel in an invisible stream at a speed of 62,900 miles per hour, nearly 10 times that of its chemical counterpart.

Hughes Electron Dynamics Division is a world leader in the design and manufacture of microwave, traveling wave-tube amplifiers, and ion propulsion systems. The earnings of Hughes Electronics are used to calculate the earnings per share attributable to GMH (NYSE symbol) common stock.

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