Orbital Anomalies in Goddard Spacecraft for Calendar Year 1994

This report summarizes and updates the annual on-orbit performance between January I and December 31, 1994, for spacecraft built by or managed by the Goddard Space Flight Center (GSFC). During 1994, GSFC had 27 active orbiting satellites and I Shuttle-launched and retrieved 'free flyer.' There were 310 reported anomalies among 21 satellites and one GSFC instrument (TOMS). GOES-8 accounted for 66 anomalies, and SAMPES reported 155 'anomalies'. Of the 155 anomalies reported for all but SAMPEX, only 4 affected the spacecraft missions 'substantially' or greater, that is, presented a loss of more than 33% of the total missions. The most frequent subsystem anomalies were Instrument/Payload(44), Timing Command and Control(40), and Attitude Control Systems(33). Of the non-SAMPEX anomalies, 29% had no effect on the missions and 28% caused subsystem or instrument degradation and, for another 28%, no anomaly effect on the mission could be determined. Fifty-three percent of non-SAMPEX anomalies could not be classified according to 'type'; the other most common types were 'systemic'(35), 'random'(19), and 'normal or expected operation'(15). Forty percent of the anomalies were not classified according to failure category; the remaining most frequent occurrences were 'design problems'(50) and 'other known problems'(35).