GPS Spin Phase Dynamics and Spindown Analysis.
Abstract
The NAVSTAR/GPS NDS-2 satellite will be spin stabilized at approximately 100 revolutions per minute during its early flight phases, but must be nearly motionless relative to its orbit and pointing at the earth during its operational lifetime. Present plans call for the despin to be accomplished in several phases, allowing the nutation damper on the satellite to remove any nutation caused during the thrusting despin phase. This study investigates several aspects of the despin operation, including probable magnitudes of error torques due to thrust misalignment. Extensive computer simulations have verified a simplified analytic model of satellite behavior which gives insight into the expected behavior of a spinning, non-symmetric body. Insight is developed into the behavior of this type body, subject to random error torques and intentional despin torques. The extremely slow spin range of 6 to 1 revolution per minute is examined, and the consequences of stopping and starting despin thrust at an intermediate speed is found to be undesirable in a 'worst possible case' sense. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1976
- Accession Number
- ADA041023
Entities
People
- Roger P. Neeland
Organizations
- United States Air Force Academy