dsc35572.jpg

This houses the Cosmic Origins Spectrograph, to be installed during the Hubble Servicing Mission. The instrument is a "high-throughput ultraviolet (UV) spectrograph that is optimized to observe faint point sources" (I don't pretend to understand that; I just copied it from the COS site :-) NASA also has an online fact sheet.

The object in the foreground/bottom is the Vehicle Electrical System Test facility (VEST).