First results from the cosmic dust aggregation experiment CODAG

The Cosmic Dust Aggregation Experiment (CODAG), an experimental simulation of the onset of planet formation, was successfully flown on STS-95 (October/November 1998) and on Maser 8 (May 1999). The main objective of the CODAG experiment was a direct observation of the Brownian motion-induced coagulation process of micron-sized dust particles. To overcome rapid sedimentation of the dust grains in the rarefied gas atmosphere, experiments were conducted in a long-duration microgravity environment. In the experiment, we observed that within several minutes the initially deagglomerated dust grains formed fractal dust aggregates due to their thermal motion and subsequent mutual collisions. The results from this experiment are the first experimental proof that the concept of pre-planetary dust coagulation is correct. (C) 2002 COSPAR. Published by Elsevier Science Ltd. All rights reserved.