Development of a deployable mechanism for a conical optical baffle for a small satellite

Abstract

Baffles in optical systems on a satellite, such as imaging payloads and star trackers, involve structures with large empty volumes that take up significant payload volume. Limiting the volume of optical systems is essential, considering the demand for small satellite platforms and rideshare launch missions. A baffle structure with empty volume can be configured to stow in a packed configuration during launch and deploy to its operational configuration once the satellite is in orbit. An analytical model for deployable conical baffles is developed to trade off various design parameters. A simple and reliable deployment mechanism with large torsion springs is designed and developed for an optical baffle. A prototype baffle is developed with representative materials, and functional testing is carried out. The deployment tests were carried out to measure the shocks and deployment accuracy. The baffle in its stowed configuration performed satisfactorily and indicated no damages when subjected to vibration testing. Further, the deployment mechanism performed adequately at a low temperature of -40°C and at 0.062 mPa during the cold functional test in a thermovac chamber. The baffle is a precursor to the flight model, which will be launched as a part of a hyperspectral imager, CyanoSat of CSIRO.