GOES SXI update vom 03.10.2003

[Ulrich Rieth]

2003-10-03

Apologies for the long delay in updating this page. The initial tests completed during the week of 09/02 helped eliminate some general possibilities regarding the SXI fault such as a temperature or time dependency rather than a dependency on the microchannel plate high voltage level. Additional testing showed no gross detector defects evident in dark images. On 09/11 an investigation panel led by NASA Goddard Space Flight Center and the NOAA Satellite Operations Control Center was formally launched. A review of design and test documentation as well as a telemetry review is currently being conducted. Testing of the engineering model hardware and computer modeling of the high voltage circuitry is progressing. A set of carefully controlled, limited imaging tests on the flight instrument have also been conducted. While there are candidate root causes for the anomaly, no clear diagnosis has been made at this time. However, an encouraging sign is that there may be a range of voltages, at and below 500V, in which the SXI may operate normally. While this voltage regime would provide greatly reduced sensitivity, it would still be possible to get useful observations from the SXI.