ORBITAL ACCELERATION RESEARCH EXPERIMENT - CALIBRATION MEASUREMENTS

The Orbital Acceleration Research Experiment (OARE), which has flown o n STS-40, STS-50, and STS-58, contains a three-axis accelerometer with a single, nonpendulous, electrostatically suspended proofmass, which can resolve accelerations to the 10(-9) g level, The experiment also c ontains a full calibration station to permit in situ bias and scale-fa ctor calibration, This on-orbit calibration capability eliminates the large uncertainty of ground-based calibrations encountered with accele rometers flown in the past on the Orbiter, and thus provides absolute acceleration measurement accuracy heretofore unachievable, This is the first time accelerometer scale-factor measurements have been performe d on orbit, A detailed analysis of the calibration process is given, a long with results of the calibration factors from the on-orbit OARE fl ight measurements on STS-58, In addition, the analysis of OARE flight- maneuver data used to validate the scale-factor measurements in the se nsor's most sensitive range are also presented, Estimates on calibrati on uncertainties are discussed, These uncertainty estimates provides b ounds on the STS-58 absolute acceleration measurements for future appl ications.