Jockeying Planetary Missions

Abstract

NASA's science budget is tight, but the agency nevertheless approved work on three planetary science proposals—to examine Venus's atmosphere, probe the moon's interior, and return an asteroid sample. Each team gets $1.2 million to provide a more detailed plan for a mission which must cost less than $425 million; the winner will be chosen next year once the studies are complete. The agency also plans to continue at least one of two missions now in flight. One option would be to redirect the Deep Impact spacecraft that visited Comet Tempel 1 in 2005 to Comet Boethin, to compare the two objects. The other choices would be to focus a camera from the same spacecraft on possible Earth-sized planets around stars, or to send the Stardust spacecraft, to check on changes to Tempel 1 since its encounter with Deep Impact. “One of the great surprises of comet explorations has been the wide diversity among the different cometary surfaces imaged to date,” says Michael A'Hearn, the University of Maryland astronomer who would lead the Boethin mission.