Star of Aoxiang: An innovative 12U CubeSat to Demonstrate polarized light navigation and microgravity measurement

摘要

The standard of CubeSats has boosted the development of nanosatellites by the end of the twentieth century. Standard CubeSats have a volume range from 1U to 3U, which limits their applications due to the difficulty of miniaturizing payloads. To facilitate the needs on a larger but low-cost satellite platform, a 12U CubeSat called Star of AOXiang (SAOX) has been developed by students and young professionals in Shaanxi Engineering Laboratory for Microsatellites (SELM), Northwestern Polytechnical University (NPU), China. The main objectives of SAOX are three-folds: 1) To investigate the feasibility of using polarized sunlight for spacecraft attitude determination and navigation; 2) To perform microgravity research using a miniaturized gravimeter, and 3) To demonstrate hopefully the world first 12U CubeSat platform and relevant technologies. Polarization is a property of waves that can oscillate with more than one orientation. Polarized sunlight has useful information for spacecraft attitude determination and navigation. The onboard Polarization Light Sensor (PLS) developed by SELM is based on the bionic research. The PLS can get the maximum polarization angle which is vertical to the solar meridian plane, and then the attitude and navigation information of the CubeSat could be collected from the polarization angle information. As the main payload of SAOX, the PLS can effectively detect the Earth's atmosphere polarization mode with the data collected in orbit, and provide a basis for the application of polarization in satellite navigation. Apart from PLS, another interesting experiment onboard SAOX is gravity field measurement, which could contribute to e.g. seismic survey and forecast, oil and gas exploration, etc. Traditional gravimeters are very big and consume high power; therefore, they are only suitable for big satellites such as GOCE. The researchers in NPU have developed a new gravimeter that is small enough and could be carried by CubeSats. By sensing the density of the micro-gravity, the gravimeter onboard SAOX could depict the distribution of the micro-gravity in LEO.