Vega missionEither of two spacecraft missions, sponsored by the USSR, France, Germany, Austria, Bulgaria, Hungary, Poland, and Czechoslovakia. The main scientific goals were to study Venus by means of balloons and landers and to fly by Halley's comet. Vega 1 and Vega 2 were launched in 1984 (Dec. 15 and Dec. 21 respectively), flew past Venus on June 11 and June 15 1985, and used the gravitational assistance of that maneuver to fly by Halley on Mar. 6 and Mar. 9 1986 at miss distances of 8890 and 8030 km. The massive three-axis-stabilized TV systems on board unfortunately produced rather blurred images of the comet's nucleus. The dust mass spectrometers and dust detectors were, however, particularly successful. Results from the Vega mission enabled ESA to target the Giotto mission more accurately.
Collins Dictionary of Astronomy © Market House Books Ltd, 2006