The Giotto mission to Comet Halley

Abstract

Giotto encountered Comet Halley on 14 March 1986, about four weeks after the comet's perihelion passage when it was most active. Giotto passed the comet nucleus at a distance of 600 km on the sunward side. Its scientific payload-comprising a narrow-angle camera, three mass spectrometers for the compositional and isotopic analysis of the neutral gas, ions and dust particles in the cometary coma, various dust impact detectors, a photopolarimeter and a set of plasma instruments-worked flawlessly and returned a wealth of data. The mission's scientific objectives, the spacecraft and the mission from launch to encounter are described. After the encounter Giotto was retargeted to return to the Earth. An Earth swing-by manoeuvre on 2 July 1990 will allow Giotto to encounter Comet Grigg-Skjellerup in July/August 1992.