The ISPM dust experiment

The ISPM Dust Experiment observes particulate matter with masses between 10 to the minus 19th power and 10 to the minus 10th power kg in the solar system; investigates its physical and dynamical properties as a function of ecliptic latitude and heliocentric distance; and studies its interaction with solar radiation, the solar wind, and the interplanetary magnetic field. Measurement of the three dimensional spatial distribution of cosmic dust particles and their dynamics allows the relative significance of their probable sources (comets, asteroids and interstellar dust) to be determined. An instrument that measures the mass, speed, flight direction and electric charge of individual dust particles is used. It is a multicoincidence detector with a sensitivity 100,000 times higher than that of previous experiments. The instrument weighs 3.750 kg, consumes 2.0 W, and has a normal data transmission rate of 8 bit/sec in spacecraft tracking mode.