The LA Section-sponsored symposium took place at the TRW Forum on three Saturday mornings in April and May. The first session, April 15 was on Microengineering; The second, on April 29, was on Advanced Technology; and the last, on May 6, was on Return to the Moon.

Session 1 featured three speakers from the Aerospace Corporation, a leader in the development of very small components/instruments and satellites. 15 attendees heard the proposed nomenclature being employed to describe such MEMS (micro-electromechanical systems) devices: Micro 10-100 kg; Nano 1-10 kg; Pico 0.1 - 1 kg; and Femto- grams.

Dr. David G. Sutton described and showed performance for centimeter-size devices such as rate gyros, accelerometers, and micro thrusters, as well as chemical and environmental sensors. Dr. Siegfried Janson described the possibilities of making mass-production silicon spacecraft utilizing semiconductor batch-fabrication techniques. Such spacecraft will have only aperture size and thermal control limitations, and multiple deployment using sparse optics techniques can overcome some of these problems. Ernie Robinson, an early proponent of microsats (1993) discussed the fabrication and testing, including tracked space missions, of a first Picosat, which weighed about 7 pounds and was a ~6x4x3/4 inch satellite with a flat ~2x2 inch antenna.

Session 2, on April 29, again had about 15 attendees, who were brought up to date on high tech advances in Smart Structures, Solar Sailing; and Anti-Matter.

Dr. Allen Bronowicki of TRW spoke on "Active Structures for Vibration and Shape Control". He discussed spacecraft programs wherein the elimination or great diminution of vibration was most important. Such programs had to point instruments with great accuracy and even the input of control gyros could affect results. Allen discussed the use of active dampers, powered by piezo-electric devices; and passive viscoelastic and mechanical isolators. He also described methods of deforming mirror/reflectors using electro-strictive ( PMN- Lead Magnesium Niobate) and magneto-strictive materials (Terfenol), as well as the use of stepper motors. Richard Wallace of JPL indicated that solar sailing depended on the photon pressure (10E-6 kg/ms-squared) and new materials which weighed on the order of 5 grams per square meter, capable of operating at 0.2 AU of the Sun. He said missions were being considered which would travel 200 AU in 15 years with a 300 meter sail. Current planetary plans include 4 ‘near term’ missions and 5 ‘far term’ missions with sails up to 1000 meters. Solar system experiment planning consists of 5 near term and 2 long term missions; these being powered by a combination of solarelectric and solar sail propulsion systems. Sail size for the latter missions will be on the order of 200 meters. Sails are generally deployed using centripetal force followed by gore wire pulling. Bill Haloulakos, a past AIAA Distinguished Lecturer, lamented the slow progress being made in anti-matter propulsion, despite some spectacular A-M advances in the medical field (ie. PET -positron emission tomography-scanning; more revealing than MRI techniques). In the propulsion arena, he pointed out that a specific impulse of 2500 seconds would permit an SSTO to carry a payload of 60% GTOW. In a comparative sense, the best electric Isp is of the order of 10E12, while A-M has the potential of 10E17. Storage of anti-matter is a problem, although magnetic bottles have been devised to trap and contain a reasonable supply. Funding is now the main problem.

The third session will be reviewed in the September/October Issue.

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