PROJECT GALILEO AT JUPITER

Galileo made a highly successful arrival at Jupiter on December 7, 199 5, The Galileo Atmospheric Entry Probe transmitted the first-ever dire ct measurements of an outer planet to the Orbiter mothership for nearl y one hour while descending to a pressure depth of 23 bar-far beyond t he 10 bar mission requirement. After storing the Probe data onboard, t he Orbiter performed an essentially perfect insertion burn to become t he first spacecraft to orbit an outer planet. In mid-March 1996, the t hird and final burn of Galileo's 400N main engine will raise the perij ove distance so that the Orbiter can survive the radiation dose accumu lation for the subsequent eleven orbits. The new flight software provi ding the onboard editing, compression, and telemetry capabilities requ ired to perform the Orbiter mission via the low-gain antenna will be u plinked in May preparatory to tile first satellite encounter-Ganymede 1-on June 27. The second satellite encounter-Ganymede 2-occurs on Sept ember 6. This paper will summarize: 1) the Probe mission results both engineering and scientific, 2) the problems with the Orbiter tape reco rder and its recovery, 3) the Orbiter engineering operations including the loading and performance of the new flight software, and 4) early science results from the arrival and first two orbits and Ganymede enc ounters. Overall mission status and the forecast for the remainder of the Orbiter's two-year primary mission will also be provided. (C) 1997 Internationa Astronautical Federation. Published by Elsevier Science Ltd.