MIRI First Light
19 May 2011



The flight model MIRI instrument opened its eyes for the first time in the Space Test Chamber at RAL.

An engineer in a cleanroom suit performing alignment testing on MIRI.

​​​MIRI undergoing alignment testing

Credit: STFC RAL Space

This major milestone marks the start of a three-month long test campaign to provide calibration data prior to delivering MIRI to NASA for integration into the James Webb Space Telescope (JWST). MIRI is the mid-infrared instrument for JWST, the successor to Hubble, and provides imaging, spectroscopy and coronagraphy from 5 - 28 microns.

STFC have led the international team developing the instrument and a key part of the UK role is the Assembly Integration and Test (AIV) campaign at RAL. 

After 10 days cooling in RAL Space’s large thermal vacuum chamber, a team of scientists and engineers from the MIRI consortium switched on the internal calibration source of the MIRI instrument for the first time on 10th May 2011.  

A engineer looking at the first light data from MIRI on the test computer.First light data

Credit: STFC RAL Space

​​The photograph above shows the instant the images appeared on the test computer. On the leftmost screen is the data from the Imager detector and shows, to first order, a flat field illumination. The middle screen shows a spectra produced by spectrometer channels 1 and 2 and rightmost screen shows spectra from spectrometer channels 3 and 4.  

The images were exactly as predicted and confirm that MIRI is in good shape to continue with the rest of the calibration campaign.

 For more information please contact: RAL Space Enquiries