3D laser micromachining, microthrusters and nanosatellites

Summary form only given, as follows. Both European and US space agencies are evaluating the use of miniature, but fully capable, satellites for specific scientific, Earth observation and communication missions. The concepts currently under study are satellites with total mass between 1-20 Kg. In 1993, The Aerospace Corporation presented a viable concept for a 1 Kg class satellite (i.e. the nano-satellite or silicon-satellite) that is designed to be mass producible using advanced fabrication techniques, microelectromechanical systems (MEMS) and advanced packaging technology. Most of the nanosatellite subsystems can be fabricated using the planar (e.g. 2D) microelectronics or the extruded 2D (e.g. also called 2.5 D) silicon MEMS processing techniques. However, for the micropropulsion subsystem the fluid flow dynamics dictates the need for true 3D material processing (e.g. an hourglass shape nozzle) to make efficient use of the limited onboard propellant. Laser material processing is being used for the rapid prototype fabrication of various micropropulsion designs. For the semiconductor materials, a CW and pulsed laser direct write tool is being used for patterning, micromachining and metalization. In addition, for this application two laser direct-write techniques are being developed-a volumetric exposure technique for the "micro-machining" of photosensitive glass/ceramic material and a non thermal surface texturing technique for enhancing surface chemical activity. The nanosatellite concept is presented in overview while the laser techniques are described in detail.