For ground operation the CCD camera is sealed by an electrically actuated,
spring-loaded door. To allow convenient ground verification and
calibration, a 100 micro-Curie Fe-55
source is installed in the inside of the door,
visible to the CCDs when the door is closed.
This source allows us to monitor the camera
performance in ground tests, and will be used in the first days
of flight operations to calibrate the CCD performance on-orbit.
The door is actuated by a thermal wax motor and
will be opened by command from the ground following
attainment of operational orbit and completion of initial instrument
checkout. Once opened in flight, it cannot be closed again.
Table of Contents ...
Thu Jul 20 11:41:09 EDT 1995