Hubble Space Telescope fine guidance sensor control systemThe fine pointing information required for the extraordinary pointing stability of the Hubble Space Telescope (HST) is provided by the fine guidance sensor (FGS), which is capable of measuring extremely small pointing errors, of the order of 3 milliarcseconds. The FGS provides this fine pointing information over a relatively large, continuous range of angles of guide stars relative to the optical axis of the telescope. The FGS accomplishes this task by a judicious design involving the following: a two-axis high precision star selector servo system; an optical deflection system that provides high reduction from shaft angle to optical angle; a unique interferometer using Koester prisms and extremely sensitive photomultiplier tubes that enable the FGS to lock onto guide stars whose magnitude may be any value over a wide range of brightness (including 14.5 Mv and fainter); and the use the large aperture of the telescope itself to advantage. This paper describes the FGS control systems involved in achieving this performance, supported by test data.
Document ID
19900051968
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Nurre, Gerald S. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Anhouse, Stanley J. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Gullapalli, Sarma N. (Perkin-Elmer Corp. Electro-Optics Technology Div., Danbury, CT, United States)