In-flight performance of the IUE

After the IUE's successful launch into an eccentric geosynchronous orbit, and following initial spacecraft checkout, observations were made of a set of high priority targets as an insurance against premature failure of the system. These were followed by the systematic performance evaluation of the various spacecraft and scientific instrument sub-systems, some of which were optimised in orbit. The optical performance of the telescope and spectrograph and the photometric performance of the SEC cameras used as spectrum detectors all seem satisfactory, but the ground data processing system although operational needs further development.