JWST Integrated Science Instrument Module

The Integrated Science Instrument Module (ISIM) is the part of JWST that contains 4 science instruments, the Fine Guidance Sensor, and the data-handling computer.

It also houses electronics that (1) control the instrument detectors and mechanisms, (2) maintain the thermal environment, and (3) provide command and data processing for the science instruments and the FGS. See Figures 1 and 2.

Figure 1. The JWST Integrated Science Instrument Module (ISIM)

The JWST Integrated Science Instrument Module (ISIM)

The JWST ISIM is shown in final preparation for thermal vacuum testing at NASA/GSFC, in spring 2016.

Figure 2. The completed ISIM

The Completed ISIM

The ISIM, complete with thermal blankets, on its way to the thermal vacuum chamber at NASA/GSFC, in spring 2016.
The ISIM Command and Data Handling (ICDH) subsystem provides the commanding, telemetry routing, and processing functions for all of the science instruments, including the Fine Guidance Sensor. The ICDH manages the event-driven science operations of the observatory and coordinates ISIM and spacecraft activities. It performs readout mode processing of the science data, that is, formatting of the science data for each exposure before transfer to the spacecraft's solid state recorder. Software resident on the ICDH analyzes portions of the data for target acquisition purposes.



Notable updates
Originally published