The need to verify the pei1ormaixc of untended instrumentation has been recognized since scientists began sending thnse
instrumems into hostile environments to quire data. The sea floor and the stratosphere have been explored, and the quality
and cury of the data obtained vified by calibrating the instrumentalion in the laboratoiy, both jxior and subsequent to
deployment The inability to make the lau measurements on deep-space missions make the calibration vthficatkin of these
insiruments a uniclue problem.