Gravity Probe-A Collection
Martin Levine, Co-Investigator (left), and Robert Vessot, Principle Investigator (right), at the time of payload delivery for flight. The assembled payload is lightweight and ready for flight. |
Welcome to the UAH Library Gravity Probe-A Collection! The documents relating to Gravity Probe-A have been collected and indexed by Dr. Charles Lundquist. Donations include Dr. Vessot's personal collection of documents relating to Gravity Probe A and from the Collection of the late Dr. Rudy Decher of UAH. Gravity Probe-A, a joint program of NASA-Marshall Space Flight Center and the Astrophysical Observatory of the Smithsonian Institution, was launched by NASA in June, 1976. It was the first test in space to explore the structure of space and time, and was designed to test the "equivalence principle" part of Einstein's general theory of relativity. The experiment was a significant step toward a better understanding of gravitational effects, since GP-A was expected to be about 500 times more accurate than any previous measurement using ground-based instruments. In the GP-A mission, all payload systems appeared to have functioned properly, including the newly-developed hydrogen MASER, NASA officials reported. Successful tracking was maintained throughout the mission. NASA's Post Launch Mission Operation Report of GP-A dated February 14, 1977, states the following: The Principal Investigator, Dr. R. F. C. Vessot began data reduction and has reported achieving 150 parts per million accuracy. The prelaunch accuracy objective of 200 parts per million from the data has thus been surpassed. Based on this report, the mission is adjudged as successful. For more information, read The basic scope of the Gravity Probe A experiment summarized from NASA News, 1976. Or read Gravitation Research Using Atomic Clocks in Space by Dr. R. F. C. Vessot, Smithsonian Astrophysical Observatory Principal Investigator, Gravity Probe A. |
