GP-B Post-Flight Analysis—Final Report - Gravity Probe B - Stanford ...

Figure D-2 below shows the distribution of these categories across the major space vehicle subsystems. Becausethe vehicle is a system, not a collection of independent components, an observation may span more than onesubsystem.TuneItemsAnalysisitemsATCGSSTRESRECDHCOMDewarFigure D-2. Observation categories by subsystemThe key observation that can be made is that the two systems that could not be completely tested on the ground– the GSS and ATC systems – gathered a disproportionately large number of observation items. The othersystems had the advantage of being nearly fully testable in the lab and thus the operational bugs could beworked out prior to launch. Since the ATC and GSS require the space environment to function completely, theyrequired the most adjustment once on orbit.GMA29 14 7 2 6 1 1 602 4 1 7Features 6 28 2 10 19 2 3 6 1 2 2 5 86NonissuesOpsissues5 2 1 3 1 3 1 1 2 195 4 1 2 1 13Sum 47 52 10 15 21 4 13 1 6 1 1 2 3 9GPSEPSGyroPMTCSECUSum524 March 2007 Appendix D — Summary Table of Flight Anomalies