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Hubble Space Telescope Reduced-Gyro Control Law Design, Implementation, and On-Orbit PerformanceFollowing gyro failures in April 2001 and April 2003, HST Pointing Control System engineers designed reduced-gyro control laws to extend the spacecraft science mission. The Two-Gyro Science (TGS) and One-Gyro Science (OGS) control laws were designed and implemented using magnetometers, star trackers, and Fine Guidance Sensors in succession to control vehicle rate about the missing gyro axes. Both TGS and OGS have demonstrated on-orbit pointing stability of 7 milli-arcseconds or less, which depends upon the guide star magnitude used by the Fine Guidance Sensor. This paper describes the design, implementation, and on-orbit performance of the TGS and OGS control law fine-pointing modes using Fixed Head Star Trackers and Fine Guidance Sensors, after successfully achieving coarse-pointing control using magnetometers.
Document ID
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Clapp, Brian R.
(Lockheed Martin Corp. Greenbelt, MD, United States)
Ramsey, Patrick R.
(Lockheed Martin Corp. Greenbelt, MD, United States)
Wirzburger, John H.
(Honeywell Technology Solutions, Inc. Greenbelt, MD, United States)
Smith, Daniel C.
(Lockheed Martin Corp. Greenbelt, MD, United States)
VanArsadall, John C.
(Sagitta Solutions, Inc. Annapolis, MD, United States)
Date Acquired
August 24, 2013
Publication Date
June 29, 2008
Subject Category
Spacecraft Design, Testing And Performance
Report/Patent Number
Meeting Information
Meeting: F. Landis Markley Astronautics Symposium
Location: Cambridge, MD
Country: United States
Start Date: June 29, 2008
End Date: July 2, 2008
Sponsors: American Astronautical Society, American Inst. of Aeronautics and Astronautics
Funding Number(s)
Distribution Limits
Public Use Permitted.
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