REDONDO BEACH, Calif. -- A micro-thruster array measuring one-quarter the size of a penny, designed by a TRW-led team (NYSE:TRW) for use on micro-, nano- and pico-satellites, has successfully demonstrated its functionality in a live fire test aboard a Scorpius sub-orbital sounding rocket.

Individual micro-electromechanical system (MEMS) thrusters, each a poppy seed-sized cell fueled with lead styphnate propellant, fired more than 20 times at 1-second intervals during the test staged at the White Sands Missile Range. Each thruster delivered 10(-4) Newton seconds of impulse.

"The test proves the technology behind this micro-thruster is well along in its development," said David H. Lewis Jr., TRW's MEMS Digital Micro-Propulsion project manager. "We're very pleased with its performance at White Sands. We believe micro-thrusters have the potential to provide on-orbit propulsion for station keeping, orbital correction and attitude control for future, very small satellites weighing from less than a pound to as much as 50 pounds."

The MEMS design, based on silicon chip fabrication technology, offers several advantages over conventional thrusters: It has no moving parts, utilizes a variety of propellants, is scalable, eliminates the need for tanks, fuel lines and valves, and fully integrates the structure of the satellite with the propulsion to power it. The micro-thruster is being developed by TRW and teammates Caltech and the Aerospace Corp. under a contract from the Defense Advanced Research Projects Agency.

The MEMS micro-thruster arrays are fabricated as a three-layer silicon and glass sandwich, with the middle layer consisting of multiple small propellant cells sealed with a rupturable diaphragm on one side and an ignitor on the other. Each cell is a separate thruster, and when ignited, delivers one impulse bit. Delivering propulsion in discrete increments by igniting thrusters in controlled sequences has lent the technology the name "digital propulsion."

TRW Space & Electronics builds communications, scientific and defense spacecraft for military, civil and commercial customers; produces, integrates and tests payloads; develops advanced space instruments; and integrates experiments into spacecraft. It is an operating unit of TRW Inc., which provides advanced technology products and services for global automotive, aerospace, telecommunications and information systems markets.

CONTACT: TRW Inc., Redondo Beach

Sally Koris, 310/812-4721

sally.koris@trw.com