Small Explorer for Advanced Missions (SEAM), a CCSDS compatible CubeSat supported on a global commercial ground network

Abstract

A large portion of CubeSat projects have either been demonstrations or educational missions, where the science or operational concept has not been in focus. For efficient use of CubeSat platforms and realization of efficient services, either for scientific or commercial purposes, a full end-to-end design is needed, where the operational concept as well as a focused scientific or commercial rationale is taken into consideration. The SEAM project (funded within European Union's Seventh Framework Programme) addresses parts of this challenge and develops operational concepts as well as on-board systems for scientific missions. The SEAM platform is using S-Band for downlink and uplink and is fully compliant to the CCSDS standards for satellite link services thus allowing compatibility with a global commercial ground station network. The project is led by the Royal Institute of Technology KTH and SSC is an industrial partner in the consortium. The 3U SEAM CubeSat is designed with an operational concept that includes on-board selection of data to download with earth in the loop, and flexible ground network scheduling. The spacecraft SBand transceiver is full duplex with a downlink data-rate capability of 3 Mbps and uplink capability up to 100 Kbps. The communication link is CCSDS compatible in both directions, and operates with COTS multi-mission ground station equipment. A newly developed onboard module, that integrates mass memory and CCSDS functionality with a direct transceiver interface, is being demonstrated in the project. The data link layer of the CCSDS standards is implemented in hardware while the network layer and the data storage coordination in the mass memory are handled by software. This functionality partitioning ensures high data throughput and performance while providing flexibility in data collection and handling. It is noted that although the satellite is small, the complexity of such spacecraft is fully comparable to scientific microsatellites and its communication systems and operational concept use technology, equipment and procedures often found in much bigger satellites. The SEAM CubeSat is planned to be launched in early 2017 and the presentation will include the latest news from the mission operations 2 Nomenclature Mbps= mega bit per second MB = mega byte LTAN = local time of ascending node SEAM = Small explorer for advanced missions