Session
Technical Session X: Subsystems
Abstract
A low cost space qualified computer using thermally and dynamically enhanced commercial circuit cards has been developed at Southwest Research Institute (SwRI) on an internal research program. This computer, the SC-6, has been fabricated, tested and delivered to clients for use on the upcoming Commercial Experiment Transporter (COMET) mission. Thermal enhancements provide conduction paths from the electronic components to the 'housing; from which the heat may be removed by conduction and/or radiation. Thermal vacuum tests confirm operation with a baseplate temperature of between -20 and +60°C. Dynamic enhancement is achieved by attaching a stiffener/damper frame directly to the circuit card to form a module. which then serves as the structural framework for the housing assembly, The structural enhancements enable the computer to survive exposure to a composite random vibration level of 14 g(rms). Electrically, the computer is implemented with multiple processors communicating over the STD bus in a master/slave configuration. This allows the user to configure a spaceflight computer with a wide variety of commercially available processor and interface cards. The current version of the SC -6 provides three CPU's; 2 Mbytes memory,' and 3 serial, 64 digital and 24 differential analog channels. The computer operates on less than 10 Watts using 28 VDC spacecraft power.
Producing a Low Cost, Space Qualified Computer by Ruggedizing Commercial Computer Cards
A low cost space qualified computer using thermally and dynamically enhanced commercial circuit cards has been developed at Southwest Research Institute (SwRI) on an internal research program. This computer, the SC-6, has been fabricated, tested and delivered to clients for use on the upcoming Commercial Experiment Transporter (COMET) mission. Thermal enhancements provide conduction paths from the electronic components to the 'housing; from which the heat may be removed by conduction and/or radiation. Thermal vacuum tests confirm operation with a baseplate temperature of between -20 and +60°C. Dynamic enhancement is achieved by attaching a stiffener/damper frame directly to the circuit card to form a module. which then serves as the structural framework for the housing assembly, The structural enhancements enable the computer to survive exposure to a composite random vibration level of 14 g(rms). Electrically, the computer is implemented with multiple processors communicating over the STD bus in a master/slave configuration. This allows the user to configure a spaceflight computer with a wide variety of commercially available processor and interface cards. The current version of the SC -6 provides three CPU's; 2 Mbytes memory,' and 3 serial, 64 digital and 24 differential analog channels. The computer operates on less than 10 Watts using 28 VDC spacecraft power.
