SIRTF cryostat requirements and development

✍ Scribed by Stephen M. Volz; Russell Schweickart; Kermit Gause; Robert Pederson

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 758 KB
• Volume: 39
• Category: Article
• ISSN: 0011-2275
• DOI: 10.1016/s0011-2275(99)00118-6

✦ Synopsis

The Space Infrared Telescope Facility (SIRTF) is the last of NASAÕs four great observatories, scheduled for launch in 2001. At the heart of the SIRTF observatory is a 363 l, super¯uid helium cryostat, designed and built by Ball Aerospace & Technologies, Inc. The cryostat houses provides the direct cooling of the three scienti®c instruments which will observe the infrared universe. One major innovation of the SIRTF observatory is that the instrument optics are launched warm, and cooled down on orbit to the ®nal operating temperature of 5 K by radiation to space and direct vapor cooling by the euent helium. To accomplish this the cryostat system design includes two cryogenic mechanisms, and must meet stringent cold alignment requirements, in addition to the thermal and mechanical performance requirements typical for space ¯ight cryostats. Currently the cryostat is completing the fabrication and assembly process, and will go into performance testing as a system in the second half of 1999. We present here the design requirements, production development of the SIRTF cryostat, and the predicted ground and on-orbit performance.