Data Analysis of a Tethered SpaceMail Experiment

摘要

The Second Young Engineers’ Satellite is a 36 kg student-built experiment that piggybacked on the Foton-M3nmicrogravity platform in September 2007. Its mission was tethered SpaceMail: a propellantless sample return fromnan orbital platform. The experiment included a two-stage tether deployment, leading to a swing of the tether towardnthe local vertical, in which finally a capsule was released from the bottom of the tethered system into a reentryntrajectory. The first deployment stage of 3.4km was completed within about 20maccuracy. The second stage startednon time and the end mass initially accelerated nominally. Then, due to an electrical problem, the tether was deployednto its full length of 31.7 km, rather than to the target length of 30 km. It was nevertheless released at the proper timenand at a near-nominal in-plane angle. Data analysis shows that the Second Young Engineers’ Satellite scientificnobjectives were achieved. The two-stage deployment trajectory could be reconstructed and the capsule trajectoryncould be estimated. The proper performance of the deployer hardware and controller was demonstrated, and tethernphysical properties were also determined. Finally, simulation and test results could be matched to flight data,nproviding both confidence and recommendations for preparation of future tether missions.