Han Zengyao

Thermodynamic analysis of a space station remote manipulator with a harmonic drive that considers an integrated thermal protection layer

To eliminate anomalies and improve the performance of a space station remote manipulator (SSRM) used in a dynamically changeable thermal environment, we analyze the thermodynamic behavior of an SSRM that considers an integrated thermal protection system (ITPS). Solar radiative heat gain and loss become equally significant as conductive heat transfers through the interior of the SSRM on orbit. A thermodynamic model of the SSRM with a sandwich ITPS structure is established on the coupling between harmonic drive and changeable thermal environment. A motion precision is proposed to evaluate thermodynamic behavior under continuously changeable thermal circumstances. Simulation results indicate that the ITPS with a corrugated sandwich structure reduces the maximum amplitude of angular position errors to 41.6%, which helps improve the motion precision of the SSRM. The feasible regions for the SSRM in the Low Earth Orbit (LEO) and Geostationary Earth Orbit (GEO) are analyzed, which shows that the proportion of feasible region in LEO is significantly larger than that in GEO.

Space debris protection design and application for Tiangong-1

After being launched on September 29, 2011, Tiangong-1 has accomplished several automatic and manual rendezvous and docking with Shenzhou, and was visited by astronauts on June 13, 2013. During the two-year course of in orbit operation, Tiangong-1 successfully outlived the critical space debris environment. This paper introduced the space debris protection technology applied on Tiangong-1 in detail, including the system-level protection with Whipple structure and the component-level protection for radiator pipes. All the protection designs were tested by ground experiments, and it is proved that the capability of anti-impact to space debris for Tiangong-1 meets the task requirement, while that for the radiator pipe is remarkably increased.