UK-4 prototype spacecraft magnetic tests

The spacecraft was tested in a magnetic test facility which uses a 42 ft. diameter coil system to produce a controlled magnetic field of high uniformity over a large central volume. The primary objectives of the tests were: (1) to determine the permanent, induced, and stray magnetic moments of the spacecraft and to assess its magnetic stability; (2) to evaluate the magnetorquer coil system; and (3) to deperm, compensate, and make other adjustments necessary to achieve satisfactory magnetic characteristics for the spacecraft. The test facility and procedures are described together with the results obtained. In addition, the problems encountered during the tests and the significance of the test findings are discussed.