NASA's James Webb Space Telescope

MIRI Successfully Completes Cryo-Vacuum Testing

News Feature April 5, 2016

MIRI team member Ori Fox stands outside NASA Goddard's thermal vacuum chamber during the testing campaign of ISIM.
MIRI team member Ori Fox stands outside NASA Goddard's thermal vacuum chamber during the testing campaign of ISIM.

This past winter, the JWST Integrated Systems Instrument Module (ISIM) underwent its third and final round of testing in a "Space Environment Simulator'' at NASA's Goddard Space Flight Center in Greenbelt, MD.  Scientists from around the globe staffed the operations center 24/7 for nearly four months to implement a series of tests on the five JWST instruments, which includes the Mid-InfraRed Instrument (MIRI).  Not even a historic blizzard could keep the MIRI team from completing their tasks.

Throughout testing, a thermal vacuum chamber housed ISIM.  This housing structure generates both cryogenic temperatures (-233 degrees Celsius) and a vacuum to test the calibration, performance, and operation of the JWST instruments under flight-like conditions.  MIRI, however, requires an additional and dedicated cooler to keep it at -266 degrees Celsius!  MIRI successfully passed all tests.  Some highlights include verification of updated electronic boards and new detector readout patterns.  Extensive data analysis of the data from the CV3 campaign is ongoing, which will ultimately yield a complete performance report and updated calibration files.

Next, NASA will connect the ISIM structure with the telescope backplane and primary mirror, commonly referred to as the Optical Telescope Element (OTE).  Together, this mega-structure will be called the Optical Telescope Element and Integrated Science Instrument Module (OTIS).  OTIS will then undergo vibrational testing, and optical tests at Goddard. OTIS, however, cannot fit in Goddard's test chamber, so further cryogenic and vacuum tests will be conducted in a huge thermal vacuum chamber that was used to test the Apollo spacecraft at NASA's Johnson Space Center in Houston, Texas.

For more information, see: http://phys.org/news/2016-02-jwst-instruments-cold.html

Categories : MIRI Instruments jwst