increasing the transmitting distance by a factor of 5 compared with using the very conventional solid reflector. Service Module Discussion The Service Module concept for this demonstrator reference configuration is essentially a stripped-down version of the Surrey Satellite Technology Microbus platform element used on all of the UoSAT missions so far launched. The Microbus consists of a stack of machined aluminium modules dedicated to performing a specific subsystem function or supporting payload activities. Each of these module elements is 330 mm square and either 28, 32 or 35 mm thick, and has a mass of 0.48 kg (28 mm) without the specific electronics, or around 2kg including the electronics. For the UoSAT series spacecraft some 11 modules are arranged in a stack bolted together at the corners (Figure 5.1-13). Discussions with SST led to the conclusion that only five of these modules would be needed, with these being as follows, • On-Board Computer Module (OBC) (32 mm) • Telecommand & Telemetry Module (26 mm) • Transmitter & Modulator Module (32 mm) • Receiver & Demodulator Module (32 mm) • CCD Camera Module (50 mm) An overview of these modules and the other Microbus modules and their capabilities is presented in the Appendix. Of specific note, the OBC is being updated to double the RAM capability from 4 to 8 MBytes, sufficient for both image and data recording. The Telecommand & Telemetry Module is capable of outputting data from some 64 individual data sources, allowing a wide range of measurements. A one second update sample rate is also available. Combined, all
RkJQdWJsaXNoZXIy MTU5NjU0Mg==