Design and development of the SIRTF cryogenic telescope assembly (CTA)

摘要

Abstract: NASA's Space Infrared Telescope Facility (SIRTF) is a 1- meter class cryogenically-cooled space observatory currently in the design and development phase. It is planned for launch in December 2001 by a Delta rocket into a heliocentric orbit. The SIRTF Observatory is comprised of the Cryogenic Telescope Assembly (CTA), the Spacecraft, and the three Science Instruments. The CTA has an 85 cm diameter aperture telescope which is cooled to its lowest operating temperature of 5.5 K by effluent vapor from the 360-liter superfluid helium cryostat. The three Science Instruments, which span an operating wavelength range from 3 to 180 $mu@m, will be maintained at a temperature of 1.4 K inside the cryostat. The required SIRTF mission lifetime is $GREQ 2.5 years. The CTA system and subsystem design as well as their technical challenges are described.!6