NASA's New Horizons Pluto Probe Ready for Launch

NASA’s New Horizons probe sits atop its Atlas 5 rocket at Cape Canaveral Air Force Station in Florida. CREDIT: NASA/KSC.

NASA's first spacecraft aimed at the edge of our solar system is ready for its more than nine-year trek to the planet Pluto and beyond, mission managers said Sunday.

The spacecraft, dubbed New Horizons, is set to launch spaceward atop a Lockheed Martin-built Atlas 5 rocket on Jan. 17, beginning a spaceflight that will stretch more than nine years to reach a planet 3.06 billion miles (4.92 billion kilometers) from Earth.

"I like to call this mission the Everest of planetary exploration," said New Horizons principal investigator Alan Stern, of the Southwest Research Institute (SwRI), Sunday during a prelaunch press briefing at NASA's Kennedy Space Center in Cape Canaveral, Florida. "It's really fantastic."

New Horizons is set to launch Tuesday from Complex 41 at Cape Canaveral Air Force Station during a nearly two-hour window that opens at 1:24 p.m. EST (1823 GMT). The McLean, Virginia-based firm International Launch Services is overseeing the space shot. The New Horizons spacecraft and its booster are set to roll out to the launch pad on Monday.

"It's the fastest spacecraft ever launched," Colleen Hartman, NASA's deputy associate administrator for science mission directorate, said of New Horizons during the briefing. "It will get to the Moon in nine hours...it will get to Jupiter in one year and nine months."

It took NASA's Apollo astronauts three days to reach the Moon in the 1960s and 1970s aboard their spacecraft, while the Cassini probe took four years to swing past Jupiter, Hartman added.

But New Horizons has more on its plate than merely speeding through the solar system.

The spacecraft is the first to reach out toward Pluto, its moon Charon and two other objects thought to be additional satellites. After flying past the planetary system at more than 31,000 miles an hour (49,889 kilometers an hour, researchers hope the probe will be able to visit at least one other icy object in Pluto's vicinity - a region dubbed the Kuiper Belt - though that phase of the $700 million spaceflight will depend on whether the New Horizons mission is extended, mission scientists said.

"Pluto is just the brightest of the many objects in the Kuiper Belt," Stern said. "It's a fossil relic of the formation of our solar system."

With its tiny size and eccentric orbit, Pluto was once thought to be a planetary misfit in our solar system. But the discovery of several other objects beyond Pluto's orbit - including a potential 10^th planet - has forced a review of that belief, researchers said.

"We know of 17 objects that could be called planets, most of which are ice dwarfs," Stern said, adding that the number is based on objects found large enough for their gravity to coalesce surrounding material into spherical shapes. "So Pluto is typical of what is probably the most populous type of planet in our solar system. It probably mimics other Kuiper Belt objects."

Researchers hope New Horizons will shed light on Pluto's ethereal atmosphere, which the planet appears to shed almost like a comet as it moves through space. During the probe's flyby, it is also expected to build detailed maps of Pluto's surface, photograph Charon and hopefully photograph the other two moons - currently dubbed P1 and P2 - discovered last fall in Hubble Space Telescope images.

"We'll basically be able to map the entire [planet]," Dale Cruikshank, a New Horizons science team co-investigator from NASA's Ames Research Center in Moffet Field, California, told reporters.

The New Horizons spacecraft is about the size of a piano and weighs about 1,054 pounds (478 kilograms). It carries seven primary instruments, including several cameras, plasma detectors and other tools to study Pluto.

New Horizons is also NASA's first planetary probe to carry a student-built instrument. Built by engineering students at the University of Colorado, the spacecraft's Student Dust Counter designed to detect tiny dust particles throughout the nine-year trek to Pluto, researchers said.

NASA officials said Pluto is the only planet ever discovered in the 20^th century, as well as by a U.S. citizen, marking the first of many bodies later found the Kuiper Belt.

Astronomer Clyde Tombaugh discovered the distant world in 1930 using a telescope at the Lowell Observatory in Flagstaff, Arizona. While the astronomer died in 1997, Tombaugh's family - his wife Patsy and two grown children - will be on hand for the upcoming launch, mission researchers said.

"We thank them for being here with us," Stern said.

While researchers will have to wait more than nine years after New Horizons' launch to get their first close look at Pluto, they have some good ideas of what they might see.

Images of Neptune's moon Triton - from NASA's Voyager 2 spacecraft - and Saturn's satellite Enceladus - taken by the Cassini probe - have hinted at some geological activity that New Horizons could find at Pluto, according to Cruikshank.

"There may be geysers, there may be jets of material," Cruikshank said. "There may even be evidence of cracking on the surface."

Stern has said it may even be possible that Pluto sports its own ring system made up of material cast off from previous impacts.

"We have a body of information as to what we'll find in the outer solar system," Cruikshank said. "But we're certainly prepared to be surprised."

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