The HEOS 2 and HELIOS micrometeoroid experiments

Abstract

Two micrometeoroid experiments based on the plasma emission caused by impacting hypervelocity dust particles are described. Since 31 January 1972 the first has been flying on the HEOS 2 satellite orbiting the earth in a highly eccentric polar orbit. The second experiment will be flown in 1974 on the HELIOS probe which will orbit the sun with a perihelion of about 0.3 AU. The aim of these experiments is to measure the mass and speed of micrometeoroids and to determine their approximate orbital elements.