Derelict Booster to Beat Pluto Probe to Jupiter
NASA's New Horizons spacecraft launches into space on a mission to the planet Pluto and beyond on Jan. 19, 2006.
Credit: NASA.

NASA's Pluto-bound New Horizons spacecraft now speeding through the Solar System is set to reach Jupiter on Feb. 28, 2007, but it will not be the first craft of its mission to reach the gas giant, mission officials said this week.

Launched on Jan. 19, New Horizons is set to swing past Jupiter and use the planet's gravity to boost it toward Pluto. But a Boeing-built rocket booster - the third stage that launched New Horizons on its way - will get there first, said Alan Stern, the mission's principal investigator, in an update this week.

Two navigation burns set for Jan. 28 and Jan. 30 to refine New Horizons' flight path will slow the craft enough to allow the Star-48 engine to overtake it, Stern said, adding that the engine will not reach Pluto before NASA's probe.

"It'll fling off in the general direction of Pluto, but will miss by 200 million kilometers because it missed the precise aim point at Jupiter," Stern told SPACE.com.

On Jan. 29, New Horizons will pass out of Earth's orbit on its mission to one of our Solar System's most distant planets. The spacecraft launched away from Earth at about 36,250 miles per hour (58,338 kilometers per hour) and should pass the orbit of Mars on April 8, mission managers said.

New Horizons carries seven primary instruments to map Pluto and its moon system, as well as study the planet's composition and atmosphere. The probe is also designed to push past Pluto and explore at least one of the more-distant, icy Kuiper Belt objects should its mission be extended.

The spacecraft is expected to reach Pluto for its flyby on July 14, 2015. The Star-48 rocket engine will reach Pluto's orbit, but not the planet itself, on Oct. 15, 2015.