The DISR cleanroom at the University of Arizona's Lunar and Planetary Lab is home to one of the DISR flight test units. This was the same unit that took the "Field Test Images" prior to the launch. In addition to the instrument, the DISR lab also contains an assortment of specially-made materials that contributed to the durability and practicality of the instrument for its cruise to Titan.
pictures coming soon!
Insulating Foam (green): This foam insulates the sensor head to protect it from radiation, impacts, and deterioration of the structural components of the sensor head during the cruise to Titan. The foam is low outgassing, which means that it is durable and prevents condensation products from forming on the optical systems because of the vacuum and cold environment of space. The green color means that the foam has not been treated to absorb stray light, and is not prepared for a space flight.
Insulating Foam (black): This insulating foam is similar to the foam covering the DISR sensor head. The black coating means that the foam has been treated to absorb stray light and therefore minimizes interference during the descent. Like the green foam, this foam is low outgassing and durable to withstand the trip to Titan.
Fiber Optic Cable: These cables are used to connect the sub-instruments in DISR, including coherent fiber bundles for the imagers and spectrometers. For example, fiber optic bundles connect each sub-instrument’s lenses and fore-optics to the detectors. All of the optical detectors depend on transmission along the instrument’s fiber optic cable network. The white color of these cables means that they have been hardened against cosmic radiation and are ready for insertion into a space instrument. This means that their percentage of transmission will not change during the seven year cruise due to radiation darkening, so that the Earth based calibrations will remain accurate.
Ceramic Spacers: These spacers are part of the DISR optical system. The ceramic material allows for thermal conduction with electrical isolation, so that all parts of the optical assembly are at the same temperature.
Space-Grade Electronics Chip: This chip is worth about $2000! It is a vital part of the electronics system which helps maintain proper functioning of the sensor head during the descent.
Optical Bench Stand: This stand was part of the optical bench used in the clean room to support the DISR flight instrument for testing and calibration
Titanium: This metal is high in strength and makes up the light weight components of the sensor head. The other parts of the instrument are made of aluminum. Some of the titanium was used to hold the critical optical assemblies to provide more precise alignment of the optics.
Fiber Optic Cabling Bundle (not radiation hardened): This bundle of fiber optic cables shows the complexity of the fiber optic network in the DISR instrument. All of the cables begin at the same light source and then extend to the different sub-instruments. The yellow color of such cabling denotes that it is not radiation hardened and thus more likely to decay with time than the fiber optic system on the flight model. These fibers are used in the self test and in flight calibration system, but not in any of the primary instrument detector optics.
Stainless Steel Screws: These screws were specially machined for the DISR flight model, along with all of the other small connectors needed to hold the instrument together. These screws have a stronger tensile strength than normal screws to withstand the stress of a flight to Titan.
Diffraction Grating: This component behaves like a prism and breaks a light source into different colored wavelengths when it enters the detector.
Platinum Resistance Temperature Sensor: The calibration of the DISR instrument is based on the temperature of its components. The temperature of different instrument subsystems is monitored with a temperature detector similar to this one.
Gold-Plated Electrical Connectors: These connectors join the sensor head to the electronics components of the instrument. A similar system of electrical connectors joins the instrument to the probe. Hence, these small connectors are very important in ensuring that the data from the descent is transported correctly. Gold plated connectors resist corrosion better than any other metal, ensuring reliable operation in a harsh environment.
Filter Window: This component is located on the front of the sensor head and allows light into the instrument for data collection. There are several such windows on the surface of the instrument.
Calibration Lamps: Lamps similar to these turn on during every in-flight checkout (16 total, once about every 6 months) while the probe has been traveling to Titan. The lamps shine on the instrument’s detectors to determine if the instrument is functioning properly. This board shows all of the lamps that the DISR team tested in order to find the three with the best optical consistency to be included on the instrument.
“Bear’s Ear” Baffle: This component blocks the reflection from the parachute and the probe from being included in the detectors’ input during the descent. This ensures that the majority of the light collected during the descent will be of Titan, rather than interfered by components of the probe
Fiber Optic Assembly: Probably one of the most crucial components of the DISR system, this piece protects the fiber optic connections that run from the instrument subsystems to the detectors, and prevents stray light from entering the optical path. This unit is specially machined of titanium.
Tantalum Foil: This metalloid coats the electronics to shield against cosmic radiation. The small pieces on display were cut to fit the surface of the electronic chips in the instrument. Blocks of tantalum are also used to provide radiation shielding for the CCD and IR detectors, which are more sensitive to radiation than the other electronic components.