Top view of ISIM with fully integrated NIRSpec, March 2014
In this picture, the Near InfraRed Spectrograph (NIRSpec) is fully integrated into the Integrated Science Instrument Module (ISIM). The Horizontal Integration Tool (HIT) via the HIT adapter, is still attached. ESA provided NASA with the HIT adapter, so that NIRSpec can be picked up and manoeuvred without damage. The strut with "+V3" written on it is part of the HIT adapter.
NIRSpec is one of four instruments on JWST. It is a multi-object spectrograph capable of observing at least 100 astronomical objects simultaneously. It will support JWST's four main science themes by providing low, medium and high-resolution spectroscopic observations.
NIRSpec is developed by ESA with Airbus Defence and Space, Germany, as the prime contractor. NIRSpec's Micro Shutter Assembly (MSA) and Focal Plane Assembly (FPA) are provided by NASA.