This piece of hardware is called the Beam Image Analyzer (BIA). It is used to test the OSIM (Optical Telescope Element Simulator) to measure the properties of the light coming out of the OSIM so engineers can tell if OSIM is projecting the correct beam of light. (OSIM is an optical simulator of the telescope, i.e., it replicates the beam of light that will come out of the real telescope to feed the instruments in the real ISIM. (The ISIM is the assembly of all the instruments together into a single structure, plus their electronics) The BIA will sit on top of OSIM when they are assembled together for OSIM testing in the big SES chamber.

Eventually ISIM will replace BIA on top of OSIM so they can be tested together. But we need to know OSIM is right before we use it to test the instruments.

Credit: NASA/Chris Gunn

<a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA Image Use Policy</a>

<a href="http://twitter.com/#!/NASAWebbTelescp" rel="nofollow">Follow us on Twitter</a>

<a href="http://www.facebook.com/webbtelescope" rel="nofollow">Like us on Facebook</a>

<a href="http://www.youtube.com/nasawebbtelescope" rel="nofollow">Subscribe to our YouTube channel</a>