NASA Reining in Pi-Led Planetary Missions

摘要

When a spacecraft called MESSENGER blasts off early next month from Cape Canaveral bound for Mercury, many planetary scientists will be holding their breath. MESSENGER is the seventh in NASA's innovative Discovery Program of planetary missions—a popular program that is now under intense review. A spectacular success, or failure, could have weighty repercussions for the entire program. NASA launched the Discovery Program a decade ago with an appealingly simple concept. As a NASA associate administrator put it at the time: "We're asking for PIs to come in with a whole mission. If we like it ... we'll buy it, pay you, and you do it." Of course, running a third-of-a-billion-dollar mission to study an asteroid, comet, or star dust was never quite that hands-off; NASA always exercised periodic oversight. Still, relatively freewheeling missions led by principal investigators have come to permeate NASA's planetary exploration programs.