Latest status of the four Chinese CubeSats in the QB50 project

In 2011, the QB50 project of European Commission's Framework 7 research program was granted. The project was initiated by Von Karman Institute for Fluid Dynamics (VKI). The primary object of the project is the measurements of the key parameters and constituents in the lower thermosphere. Now there are 36 CubeSats from twenty-six countries and regions in the international project. Four Chinese universities in the mainland, Northwestern Polytechnical University (NPU, Asia coordinator), Harbin Institute of Technology(HIT), Nanjing University of Science and Technology (NUST), National University of Defense Technology (NUDT) join the QB50. Each of the universities built a 2U(10cm × 10cm × 20cm) CubeSat. They are Aoxiang-1(NPU), LilacSat-1(HIT), NUDTSat(NUDT) and NJUST-2(NUST). Among them, three CubeSats carry the Ion/Neutral Mass Spectrometer, which is used to resolve the major constituents in the lower thermosphere, i.e., O, O2, N2. NJUST-2 has a Flux- Probe Experiment science payload for the measurements of atomic and molecular oxygen densities. Besides, the lower thermosphere research, the four CubeSats will also carry some innovative experiments, which are high precision attitude control use compacted attitude control module, high reliable onboard computer test, high precision orbit determination by GPS/BDS receiver, amateur radio communication forwarding test and space photography. Chinese universities' four QB50 CubeSats are the earliest granted CubeSat project in China, hundreds of students and young scholars join the science research in six years. Now, all the CubeSats have been launched and deployed in 2017. This paper will give the detail introduction of the payloads, the design of the four CubeSats, and other interesting experiments.