1、Lessons Learned Entry: 0518Lesson Info:a71 Lesson Number: 0518a71 Lesson Date: 1994-08-03a71 Submitting Organization: LARCa71 Submitted by: Bernard LewisSubject: Successful Prototype Reel Mechanism for use in the Gateway Tether Experiment Description of Driving Event: The Gateway Tether Experiment (
2、GATE) is a single tether satellite system that will develop and test control technology for a tethered system. Originally a free flying tethered system released from a gateway special canister on the orbiter, the system is now one experiment in the Tether Dynamics Explorer (TDE) series launched by a
3、 Delta II. The system consists of a Delta II second stage and subsatellite connected by a single tether. The subsatellite contains a motorized reel mechanism that will be the primary means of control actuation. A prototype reel mechanism has been constructed for use in the GATE system and ground tes
4、ted. The reel mechanism consists of a spool and a level wind mechanism that are driven by independent stepping motors. The spool is designed to hold 1.8 km of 0.075 cm diameter tether.A paper, “Ground-based Implementation and Verification of Control Laws for Tethered Satellites“, by David A. Gwaltne
5、y (NASA Langley Research Center) and Michael E. Greene (Auburn University) was published in the Journal of Guidance, Control, and Dynamics in the edition of January-February, 1992 (pages 271-273). The paper contains system equations and discusses testing and testing results.Lesson(s) Learned: Tether
6、ed system technology has advanced to the point where an apparently successful prototype reel mechanism has been constructed for use in the Gateway Tether Experiment.Recommendation(s): Test results show that:Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS
7、1. The prototype reel mechanism performs satisfactorily compared to simulations.2. Deployment and retrieval rates appear adequate for space-based systems.3. Length errors were within acceptable limits.4. The Yo-Yo damping scheme was shown to be successful.Evidence of Recurrence Control Effectiv
8、eness: N/ADocuments Related to Lesson: N/AMission Directorate(s): N/AAdditional Key Phrase(s): a71 Research & Developmenta71 SpacecraftAdditional Info: Approval Info: a71 Approval Date: 1997-04-02a71 Approval Name: Elijah C. Kenta71 Approval Organization: 421a71 Approval Phone Number: 757-864-3345Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
