Cosmic Dust Analyzer

This instrument employs a larger sensitive area (0.1 m2) impact detector, a smaller time-of-flight mass spectrometer chemical analyzer and two high rate polarized polyvinylidene fluoride (PVDF) detectors, in order to cope with the high fluxes during crossings of the E ring.

Major contributions were provided by the DLR in Berlin-Adlershof (mechanics, cleanliness, thermal design, tests), Tony McDonnell from University of Canterbury (chemical analyzer, UK), Rutherford Appleton Laboratory (spectrometer electronics, UK) and G. Pahl (mechanical design, Munich, Ger).

In 1990 the PI-ship was handed over to Ralf Srama from the Max Planck Institute for Nuclear Physics, who is now at the University of Stuttgart, Germany.

Ralf Srama got his degree “Dr.-Ing.” from the Technical University of Munich for his Thesis (10 Nov. 2000, in German), "From the Cosmic-Dust-Analyzer to a model describing scientific spacecraft".

Ions are partly collected by the semi-transparent grid at 230 millimeter distance and the center electron multiplier.

CDA measured the micrometeoroid environment for 18 years, from 1999 until the last active seconds of Cassini in 2017 without major degradation.

In order to obtain some more control of its pointing attitude, CDA employed a turntable between the spacecraft and the dust analyzer.

During the Cassini spacecraft’s Grand Finale mission in 2017, it performed 22 traversals of the region between Saturn and its innermost D ring.

For most of Cassini’s orbital tour CDA observed a faint signature of interstellar dust in the largely dominant foreground of E ring water-ice particles.