SIRTF — The moderate mission

The Space Infrared Telescope Facility (SIRTF) has been planned by NASA and the US scientific and aerospace communities as a cryogenically-cooled observatory for infrared astronomy from space. Within the past few years, severe pressures on NASA's budget have led to the cancellation of many programs and to dramatic rescoping of others; SIRTF is in the latter category. This paper describes the resulting redefinition of SIRTF and the technical innovations which have made it possible to package SIRTF's key scientific capabilities into the envelope of a moderate-class mission.