Breakthrough silicon machining technology and electronics for miniature gyroscopes and navigation units that are lighter, cheaper, higher performing, simpler and longer-lived than conventional instruments are now under development at Boeing Satellite Systems (BSS), Inc. Under a $1 million dollar Defense Advanced Research Project Agency (DARPA)

The microgyroscope is smaller than a dime with resonator dimensions of 4 mm by 4 mm.

contract awarded in 1999, BSS is working to demonstrate the feasibility and performance of a packaged Silicon, vibratory mesogyroscope designed for use in space navigation. BSS is developing this technology jointly with NASA's Jet Propulsion Laboratory (JPL), a division of the California Institute of Technology in Pasadena, Calif. Superior space and terrestrial performance over a very wide range makes the devices potentially useful for military and civilian navigation, automobiles and missiles, as well as spacecraft.

BSS already holds a license to the background technology for an even smaller and complementary cloverleaf micro-gyroscope originally conceived for stabilization and control of micro-spacecraft.

Marking a qualitative step forward in gyroscope development, this gyroscope-on-a-chip duo will make it possible for spacecraft of all sizes to enjoy continuous use of reliable "inertial stabilization," a balancing mechanism not unlike the human inner ear. The sturdy devices are smaller than a dime for the microgyro to slightly larger than quarter size for the mesogyro. The devices have no rotating parts to wear out and work by measuring vibrations. Able to resolve rotation 30 times and 3,000 times slower than a clock's hour hand, they can detect even the extremely slow rotation of a spacecraft, large or small, enabling it to maintain proper orientation at all times.

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. By contrast, the newly developed JPL/Boeing Silicon gyroscopes do not have any specific life-limiting features; the resulting long life of more than 15 years is a significant plus for space applications.

While uniquely designed for continuous space operation, these new gyroscopes are lighter, cheaper, higher performing and have fewer components than their conventional counterparts. The microgyro resonator 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). It is best utilized in very low-cost distributed sensors and

The mesogyroscope is approximately the size of a quarter with resonator dimensions of 20 mm by 20 mm

micro-spacecraft stabilization applications. The mesogyro resonator dimensions on the other hand, are 20 mm by 20 mm, but it promises to deliver a much greater navigation and pointing precision required by larger space observatories and broadband communications satellites. The basis for the new mesogyro technology development is the silicon machining and Coriolis sensor electronics jointly developed by BSS/JPL for the cloverleaf microgyro. The mesoscale approach exploits the inherently high material quality of crystal silicon and enables greater than 100-fold improved three dimensional manufacturing precision compared to millimeter scale microgyros. A proof of concept demonstration in a vacuum chamber was completed this year leading to a mid-2002 demonstration of a 0.1 degree/hour, packaged meso-gyroscope.

Other navigation-grade gyroscopes designed for 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.

This complementary duo of silicon gyroscopes, now for both 'macro-spacecraft' as well as micro-spacecraft, including their common control electronics, were created out of a technology cooperation agreement between BSS and JPL that began in 1997. In 1999, Boeing acquired exclusive rights from the California Institute of Technology to develop the microgyro for commercial space applications. Caltech has the right to elect title to inventions developed at JPL under its contract with NASA to manage JPL.

BSS is the world's leading manufacturer of communications satellites and a major provider of space systems, satellites, and payloads for national defense, science and environmental applications.

Performance 0.1 degree/hour rate bias stability by mid 2002 Production Unit Cost Goal $2,500 in quantities of 3,000 Volume 4.5 cubic inches Power 1 watt Operating Environment -54 degrees C to +85 degrees C temperature, 0-100 g acceleration and any altitude Inertial Measurement Unit Demonstration Mid 2004