Title: CloudSat's return to the A-Train
Authors: Ian J. Gravseth; Brian Pieper
Addresses: Ball Aerospace, 1600 Commerce St. Boulder, CO 80306-1062, USA ' Ball Aerospace, 1600 Commerce St. Boulder, CO 80306-1062, USA
Abstract: This paper discusses CloudSat rejoining the A-Train after multiple faults from a severe battery anomaly on April 17th 2011 left the vehicle in a power-positive, but passive state. After diagnosing the anomaly, the CloudSat team developed and tested a new method of operations which limited active operations to the sunlit portion of the orbit. Following a pair of orbit lower manoeuvres, CloudSat drifted uncontrolled for several months and regaining and maintaining its slot in the A-Train requires the ability to perform time critical burns including lowering and raising the orbit and inclination burns. This paper discusses the operational constraints on burns caused by these new operational limitations, and the methods the team developed to insure that all the vehicle's constraints were met. Performance for the vehicle during the campaign to rejoin the A-Train and the subsequent orbit maintenance burns are documented.
Keywords: formation flying; CloudSat; orbit maintenance; attitude control; A-Train constellation; battery anomalies; time critical burns; spacecraft orientation; observation satellites.
International Journal of Space Science and Engineering, 2013 Vol.1 No.4, pp.410 - 431
Received: 24 Jul 2013
Accepted: 06 Sep 2013
Published online: 30 Apr 2014 *