Microgravity Flight Testing As A Case Study On The Student Space Systems Fabrication Laboratory

As a student-run organization, the Student Space Systems Fabrication Laboratory (S3FL) provides over a hundred undergraduate and graduate students each year with the opportunity to work on real-world, design-build-test space systems projects. Such opportunities include the microgravity flight experience available through NASA’s Reduced Gravity Student Flight Opportunities Program. By having a proposal accepted through a competitive evaluation process, students can design and fabricate an experimental payload that flies onboard a C-9 plane whose parabolic flight trajectories permit short periods of microgravity test conditions. During August 2006, S3FL flew a C-9 microgravity test payload in support of the lab’s Tethered SATellite Testbed (TSATT) project, now known as the Tethered Satellite Ionospheric eXplorer (TSIX) satellite. In accordance with the 2004 Presidential Commission Report that realigned NASA’s objectives, TSATT is a tethered nanosatellite mission for demonstrating the feasibility of a tethered satellite system as a suitable platform for validating rendezvous and formation flying sensors and algorithms. Once released from the launch vehicle, the initially joined end masses will separate from each other while remaining connected by a high-survivability tether. Through use of a variable-length tether deployer and retriever, sensor performance at multiple, controlled nanosatellite separation distances can be tested. Also, the nanosatellite pair provides well-defined, close-flying passive targets for long-term tracking and calibration of ground-based sensors for space situational awareness applications. To ensure mission success, S3FL is validating as much of the system design as possible through prototyping and ground testing. Since separation of the nanosatellite pair is a potential single point of failure for the TSATT mission, the functionality of the in-house designed separation mechanism must be validated prior to the actual mission. A C-9 flight permitted such a test in a zero-gravity operating environment, and it also provided an opportunity to record end mass dynamics at separation for different system tumbling conditions. This data will be useful for refining predictive dynamics models for the TSATT mission and future tethered space systems. This paper discusses the S3FL C-9 Tethered Satellite Dynamics at Separation Investigation Team’s (TSSIT) design-build-test experience from project conception and requirements definition through flight testing and post-flight redesign work. In particular, the paper evaluates how the C-9 project enabled S3FL students to apply classroom knowledge in a real-world, interdisciplinary setting, to experience working through a complete design cycle, and to develop a systems engineering mindset.