This award will support a two-year cooperative research project between Professor Christopher T. Russell, Institute of Geophysics and Planetary Physics, University of California, Los Angeles (UCLA), and Professor Willibald Riedler, Institute for Space Research, Austrian Academy of Sciences, Graz, Austria, and their respective research groups. The scientists will jointly study available data on the interaction of the solar wind with small bodies in the solar system. The scientific objectives are (1) experimental investigations of the influence of comets, asteroids, and meteor streams on the interplanetary medium; (2) modelling of the potential mechanisms of interaction between the interplanetary medium and these minor bodies of the solar system; and (3) development of new data processing and analysis methods to improve the investigation of events which might be caused by these interaction processes. Professor Riedler and his Austrian colleagues were successful in probing Halley's comet in 1986 with instruments on board the Soviet spacecraft VEGA 1 and 2, and are preparing instruments for the Phobos mission to Mars, expected to be launched by the U.S.S.R. in 1988. Through this U.S.-Austrian cooperative project, Professor Russell and his research group at UCLA have access to the VEGA data from Comet Halley and to the personnel who can assist in working with those data. Professor Russell also expects to have access to magnetic field data from the Soviet Mars 2, 3, and 5 missions as a result of this collaboration. Analysis of these latter data should lead to a greater understanding of the solar wind interaction with Mars, as well as help prepare for future Mars missions. The scientists also plan to exchange modelling results and to develop improved software for scientific analysis and on-board processing of data. Professor Russell and members of his research group have been active in observational and theoretical studies related to the interaction of the solar wind with solar system bodies for many years. Professor Riedler and his colleagues have been involved in parallel studies. Cooperation between the groups should enhance their respective research programs considerably. Funds from this award would support necessary transportation and subsistence expenses for the U.S. principal investigator and members of his research group. The Austrian Science Foundation (FWF) is providing counterpart support for the project and has approved the inclusion of this activity under the Memorandum of Understanding between the NSF and the FWF.
