The Gravity Probe B Relativity Mission uses a fused-quartz optical star tracking telescope as the sensor for the control system which points the spacecraft towards its guide star. The telescope is cooled to <5 K while the readout which uses photodiodes and JFET preamps operates at 72 K. It is mounted on the front end of the telescope with a thermal standoff. Analysis indicates that the telescope is capable of providing sub-milli-arc- second (marcs)pointing stability information with an angular pointing noise of (formula available in paper) for the guide star IM Pegasi. We describe the design of the telescope and test results under nominal operating conditions. Analysis of the expected performance of the telescope in flight, based on the test results, is also presented.

Date Published: 15 October 2003
PDF: 11 pages
Proc. SPIE 5172, Cryogenic Optical Systems and Instruments X, (15 October 2003); doi: 10.1117/12.513934

Published in SPIE Proceedings Vol. 5172:
Cryogenic Optical Systems and Instruments X
James B. Heaney; Lawrence G. Burriesci, Editor(s)