Small Satellites: The Desire for a Mass Producible, Mass Customizable Nanosatellite

Abstract

Small satellites played a key role at the dawn of the Space Age. It could very well be the case that their progeny will pave the way for satellites of Generation-after-Next where they are produced as mass produced commodities. The Aerospace Corporation, a California nonprofit corporation operates a Federally Funded Research & Development Center sponsored by the Air Force, is conducting research and technology development to radically change the way satellites are designed, manufactured and assembled. One critical area of investigation is whether the structural material of a satellite needs to be made of metal or carbon/polymer composite, as it is currently done, or whether glass ceramics could be used where it becomes possible to integrate electronic, RF, optical and fluidic functions on the same structural substrate. Since their invention nearly 60 years ago, glass ceramic materials have been used in a wide range of applications from human health (e.g., medical and dental) to consumer commodities (e.g., electronics) to transportation (e.g., aerospace). The material class has technological appeal since it is manufactured in the glassy amorphous phase and can be shaped via low cost “plastic” molding techniques, and then converted via a heat treatment step to the ceramic form. The photostructurable glass ceramics (PSGCs) are a subclass of the glass-ceramics. These materials include photo-sensitizer compounds that initiate the ceramization process. The advantage of the PSGC materials is that they can be lithographically patterned and the exposed areas can be subsequently converted into at least two ceramic phases, one of which is soluble in dilute hydrofluoric (HF) acid. Consequently, the fabrication of intricate microstructures by lithographic or laser direct-write techniques is now a commercial success. Because the material transformation process is photolytically initiated, other material properties can also be “activated” on a local scale through patterning. In a series of investigations, we have developed specialized laser direct write irradiation tooling that explores the effect of metered exposure to alter specific material properties. For the commercially available PSGC Foturan™ we can alter the chemical solubility, mechanical strength, optical transmission, RF and acoustic properties. Other published work has demonstrated changes in the optical index. We have applied this knowledge in the development of an integrated cold gas propulsion system for a 1kg class nanosatellite vehicle that is largely made of PSGC materials. The micropropulsion system includes valves, electronics, wireless telemetry and a control system to demonstrate “leader-follower” or station keeping maneuvers on an air table. PSGC like materials can be used as a structural small-satellite material and this simple change of material choice could usher in the use of digital-direct-development methodologies and the manufacturing of nanosatellites in mass production quantities. All trademarks, service marks, and trade names are the property of their respective owners.