This an engineering prototype for the mirror transport mechanism for the Far Infrared Absolute Spectrometer (FIRAS) that flew on the COBE spacecraft (see catalogue #19960298000). This instrument used a Michelson inteferometer to capture the spectra of regions of the sky. The incoming beam was split in two by means of a semitransparent mirror. The two resulting beams were then sent to the mirrors on this object. Interference patterns were created as the mirrors moved towards and away from each other to change travel distances of the light beams. The spectrum of the incoming radiation was reconstructed from the interference pattern by a mathematical technique called called Fourier Transformation. The flight instrument that it represents sent back data for the 10 months during which the supply of liquid helium was adequate to cool the cryostat to 1.5 K. It performed 1.6 full scans of the sky in that time. It provided a wealth of data that helped support and elucidate the Big Bang theory of the creation of the Universe.
This prototype was built at NASA's Goddard Space Flight Center and transferred to NASM in 1997.
Display Status
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.
Object Details
Country of Origin
United States of America
Type
INSTRUMENTS-Scientific
Manufacturer
NASA, Goddard Space Flight Center
Dimensions
3-D: 45.7 x 30.5 x 30.5cm (18 x 12 x 12 in.)
Materials
Overall - glass, steel
Inventory Number
A19960298010
Credit Line
Transferred from the National Aeronautics and Space Administration
Data Source
National Air and Space Museum
Restrictions & Rights
Usage conditions apply
For more information, visit the Smithsonians Terms of Use.