Versatile, Dual-Use Gyroscope LicensedANEW HIGH-PERFORMANCE, LONG-LIFE gyroscope that serves as a balancing "inner ear" for spacecraft has been licensed by the Jet Propulsion Laboratory (JPL) in Pasadena, California, to the Hughes Space and Communications Company in El Segundo, California, for commercial space applications. Jointly developed by JPL and Hughes, this new gyroscope is lighter, cheaper, higher performing and less complex than its conventional counterparts while uniquely designed for continuous space operation. Unlike its microgyro counterparts, the JPL/Hughes instrument features superior performance in both space and terrestrial environments, making it a versatile, dual-use technology.
"This agreement typifies the type of cooperation between the space program and industry that provides benefits back to American business," said Merle McKenzie, manager of JPL's Commercial Technologyand Regional Economic Development Program. Spacecraft require gyroscopes to maintain orientation in flight. Gyroscopes determine changes in angular direction, traditionally by virtue of a rapidly spinning, heavy mass. Spinning mass gyroscopes, originally the gyroscopes of choice for space applications, require lubrication and eventually wear out. Other gyroscopes designed for use in space use solid-state technology—that is, without any moving parts—and provide the required long lifetime, but these instruments are very expensive, power-hungry and bulky, weighing up to 20 pounds or more. The newly developed JPL/Hughes microgyro does not have any specific life-limiting features. Its dimensions are 4 by 4 millimeters (0.16 by 0.16 inches), smaller than a shirt button, and its weight is less than one gram, just under 0.03 ounces. The resulting long life of more than 15 years is a significant plus for space applications. Current gyroscopes on a chip, only useful for some terrestrial applications, can measure rotation at just over the speed of the minute hand on a watch, but no slower, whereas the newly licensed microgyro can measure rotation 30 times slower than the hour hand. In the world of gyroscopes for space, the measurement of extremely slow rotation is highly desirable—the slower the better—because the slowest of rotations can take a spacecraft significantly off target over an extended period. Like its current microgyro counterparts, the JPL/Hughes version relies on the measurement of vibrations. "The heart of the instrument is a cloverleaf design that is tied down (to a silicon chip) and vibrates at a very high speed," said JPL's Dr. Tony Tang, the engineering lead for the development of the instrument. "We look for changes in the vibration of a light piece of micromachined silicon that has no moving parts." The exclusive use of silicon helps reduce costs because this durable material is now routinely used for computer chips and is thus more easily fabricated than other materials. For more information, contact John Watson at the Jet Propulsion
Laboratory. Call: 818/354-5011, |
|||
