Spitzer's CTA Outer Shell

Spitzer's Outer Shell After Assembly Lockheed Martin

Spitzer's outer shell is made up of a dust cover, outer shield (cooled by helium vapor), thermal shields (which block radiation from space), and the solar panels. The telescope and cryostat are surrounded by the outer shell. The shell keeps exterior heat from reaching the telescope and instuments by radiating it out into cold space.

The outer shell is made of lightweight, aluminum honeycomb sandwich construction. It is painted black on the anti-sun side, for efficient thermal radiation to cold space, and is shiny on the sun-facing side, for efficient rejection of heat from the sun and solar panels. To maximize the helium lifetime, the outer shell temperature must be as low as possible. The sources of heat to the outer shell are the spacecraft bus, solar panel, and star trackers.

The outer shell is closed at the top by an ejectable cover which lets out unwanted dry nitrogen which, if left in, could contaminate the telescope's mirrors and other surfaces. The thermal shields are sized and shaped such that the observatory is shaded at all times when pointed properly.

The Spitzer Space Telescope is a NASA mission managed by the Jet Propulsion Laboratory. This website is maintained by the Spitzer Science Center, located on the campus of the California Institute of Technology and part of NASA's Infrared Processing and Analysis Center.