25 YEARS OF COMMERCIAL COMPONENTS IN SPACE: THE SURREY EXPERIENCE
- Paper ID
IAF-98-U.4.01
- author
- company
Surrey Space Centre University of Surrey
- country
United Kingdom
- year
1998
- abstract
The rapid advances made in VLSI electronic components has catalysed their use in small satellite programs, significantly contributing towards a ‘faster, cheaper, better’ approach to space missions. Affordable small satellites, however, require some differing techniques to those of the established space engineering regimes. Furthermore, the rapid development cycle of modem microelectronics devices and their packaging profiles for the commercial and domestic markets constitute a radical departure from the assurance base offered by the now dwindling Mil Standard component lines. Since 1979, the University of Surrey (UK) has pioneered costeffective engineering solutions for small satellites and has developed a series of highly sophisticated, yet inexpensive, 'microsatellites'. Fourteen such microsatellites carry communications, space science, remote sensing and in-orbit technology demonstration payloads - both civil and military - providing rapid response and affordable access to space through substantial use of commercial-off-the-shelf (COTS) components. This paper presents a summary of techniques employed dining 25 years of designing space hardware systems during which an increasing proportion of “COTS” general electronic components have been utilised and supports this with the experience during more than 60 orbit-years operation of SSTL microsatellites in LEO. It describes techniques that have been undertaken within small/medium-sized organisations producing microsatellite platform systems, payloads, and research instrumentation where component qualification by long-term environmental test regimes is unavailable. A total engineering philosophy has evolved addressing the many different issues that are relevant to “COTS” usage. These include component selection processes and verification of their suitability for space applications; a hardware design concept that reflects system reliability requirements; addressing the more essential bus services with higher levels of partial or full redundancy and a conservative design change cycle that utilises components with an established pedigree. This philosophy relies on sound engineering practice whilst ensuring that the specified quality of a component is not given a completely inappropriate status. Factors such as component handling, board level design, build quality, sub assembly compatibility, system structure, interconnection techniques and modes of operation are all factors of the total reliability. The ultimate test is long term exposure to the space environment and this paper details the results to date from the microsatellite programme at Surrey. The conclusion of this work is that for many space applications “COTS“ suppliers provide a comprehensive range of devices with improving performance and quality, such items can be used with a high degree of confidence if supported by a regime, compatible to the requirements imposed by new technologies.