Pending completion of environmental reviews and launch approvals, the spacecraft would launch from Cape Canaveral Air Force Station, Fla., during a 35-day window that opens Jan. 11, 2006. The boost from the Atlas V and a STAR-48B kick motor would send the relatively light New Horizons on the fastest spacecraft trip ever to the outer solar system, reaching the moons orbit distance less than 9 hours after launch and zooming through the Jupiter system just 13 months later.

Jupiter's gravity assist would put the 1,000-pound craft on course for a five-month-long flyby reconnaissance of Pluto-Charon in summer 2015, when the double planet would be about 3.1 billion miles from Earth. As part of an extended mission, the spacecraft could also head farther into the Kuiper Belt to examine one or two of the ancient, icy mini-worlds in the vast region at least a billion miles beyond Neptunes orbit.