NASA Probe Enroute to Pluto in Good Health
To be dispatched early 2006, the outward bound New Horizons spacecraft will throw new light on distant Pluto and its moon, Charon, as well as Kuiper Belt objects. Image
Credit: Dan Durda

NASA's New Horizons probe hurtling towards the distant planet Pluto is in working order after a series of instrument checks, the mission's top scientist said Thursday.

New Horizons principal investigator Alan Stern said almost all of the spacecraft's seven instruments have been checked after weeks of tests.

"It's really going spectacularly well," Stern told SPACE.com of the spacecraft, which is set to reach Pluto by 2015 after a Jupiter flyby early next year. "The whole approach to testing a spacecraft is to walk before you run."

Six of the seven instruments aboard New Horizons have been turned on to check their health and functionality, said Stern, who also serves as executive director of the space science and engineering division at the Southwest Research Institute in Boulder, Colorado. Two tools, the spacecraft's Student Dust Counter and its Solar Wind Analyzer around Pluto (SWAP), were expected to have seen first light by today, he added.

Built for NASA by the Applied Physics Laboratory at Johns Hopkins Univeristy, New Horizons launched spaceward on Jan. 19 on the first-ever mission to explore Pluto, its moons and the odd Kuiper Belt Objects on the edge of the solar system. That flyby is expected to occur in July 2015 after the probe grabs a gravity boost from its Jupiter pass in early 2007.

"We're very heavily invested in the Jupiter science planning," Stern said, adding that mission planners need to have the observation sequences of that flyby ready by October 2006. "We have a pretty tight schedule, and we still have some spacecraft checkout to do. But we're above 90 percent now."

At least one New Horizons instrument must wait until the probe flies closer to Jupiter before its aperture door can be opened and initial tests can be performed.

The spacecraft's extremely sensitive Long Range Reconnaissance Imager - or LORRI - must wait until the probe flies deeper into space where sunlight levels are lower, Stern said.

"After launch, the issue has to do with accidental sun-pointing," Stern said. "LORRI is so sensitive we have to wait until we're almost to Jupiter to check it."

New Horizons mission planners expect to complete their initial round of instrument checks by mid-April.

The probe should begin its first round of calibration activities, including some observations, in late May, Stern added.