These instruments are divided into two main categories: instruments which measure atmospheric aerosol particle makeup and instruments which take pictures of the surface. The DISR instrument is one of the most complicated optical instruments to ever be sent on a space mission.

the instrument, or "sensor head" (front and side views)

Descent Imager- Spectral Radiometer Quick Facts

DISR’s scientific instruments will focus on understanding the following areas:
1. the nature and distribution of photochemical haze in Titan’s atmosphere
2. the heat balance of Titan’s atmosphere
3. the nature of the surface and its interaction with the atmosphere
4. the atmospheric composition of Titan

Titan is the last unexplored frontier in the solar system. Interest regarding this moon as a target for a probe arose during the Pioneer and Voyager missions, which returned pictures of Titan’s impermeable methane-rich atmosphere.

The original proposal for the DISR instrument was submitted in 1990.


Each of the cameras in the imaging system takes a picture of Titan's surface in a different direction and at a different resolution to produce a "triplet" collection of three images which may be combined with other triplets to create a mosaic of the surface.

During the descent, the imaging system will collect over 700 images of Titan’s surface at various altitudes and resolutions.

When the probe is 700 meters above Titan’s surface terrain, the surface science lamp will turn on, illuminating Titan’s features near the landing site.

Huygens’ batteries will allow DISR to collect data for twenty minutes on the surface if the probe survives impact.

DISR was built by a collaboration of Martin-Marietta and local Tucson companies.

Three DISR flight models were built: DISR I (in Germany), DISR II (at LPL), and DISR III (onboard Huygens).