scope:

Abstract:

A commercial reference antenna used to test the Cassini-to-Probe RF link wrongly indicated that the spacecraft and probe antenna polarizations were both incorrect. The GSE reference antenna was then tested against other antennas of known polarization and found to be mislabeled. The functional attributes of vendor provided equipment cannot be assumed to match specifications, particularly when an item is to be used as a reference standard. Assure independent testing of critical features of commercial instrumentation, review interface control documents and drawings, and conduct spacecraft-level tests of all telecom interfaces.