World’s first Pluto mission lifts off from Florida

By Irene Klotz

CAPE CANAVERAL, Florida (Reuters) – The world’s first mission to Pluto blasted into space on Thursday on an unmanned Atlas 5 rocket to begin a 9 1/2-year journey to the only unexplored planet in the solar system.

After two days of delays due to poor weather and a power outage, the 197-foot-tall (60-metre-tall) rocket, built by Lockheed Martin Corp., lifted off at 2 p.m. (1900 GMT) from Cape Canaveral Air Force Station.

The launch team remained on edge until 45 minutes later when the plutonium-powered spacecraft finally and successfully separated from the Atlas’ second and last upper-stage rocket booster. The engine firings made the probe, called New Horizons, soar at 10 miles per second, or 36,000 mph (58,000 kph) — the fastest man-made object ever to leave Earth’s orbit.

If the Apollo astronauts had been launched at that speed, the trip to the moon would have taken about nine hours instead of three days, according to Colleen Hartman, NASA’s associate administrator for space science.

Even so, the grand piano-sized New Horizons will still need to bounce off Jupiter’s gravity field, in a "slingshot" maneuver that will give it added velocity, to make its 3 billion mile journey to Pluto in less than a decade.

High winds at the Florida launch site forced the first scrub of the launch of the New Horizons spacecraft on Tuesday, followed on Wednesday by a storm-triggered power outage at the mission control center in Laurel, Maryland.

With an unprecedented five solid-fuel strap-on boosters, the largest expendable rocket in the U.S. fleet sent the relatively small spacecraft hurtling into the sky and it quickly disappeared over the Atlantic Ocean.

RADIOACTIVE PLUTONIUM ON BOARD

The launch sparked a small protest and was overseen by the Department of Energy because the spacecraft carried 24 pounds (10.9 kg) of radioactive plutonium that will decay over time, providing heat that the probe’s generator can turn into electricity to power instruments and systems.

NASA has used the non-weapons-grade plutonium, processed into ceramic pellets, for 24 previous science missions which, like New Horizons, travel too far to tap the sun’s energy for solar power.

Next year, the spacecraft is expected to pick up an additional 9,000 mph (14,500 kph) when it bounces off Jupiter’s massive gravity field. If successful, New Horizons will reach Pluto and its largest moon, Charon, in July 2015.

Pluto is the largest and best known of a relatively new type of planetary body called a Kuiper Belt object. The Kuiper Belt is located beyond Neptune’s orbit, which is 30 times farther away from the sun than Earth. It contains frozen objects believed to be leftovers from the formation of the solar system 4.6 billion years ago.

While not much is known about Pluto, by the time the probe arrives, scientists may have a better idea of what to look for. A capsule containing samples of a Kuiper Belt-formed comet were returned to Earth on Sunday.

"For all the ideas and theories that people might have, we have some real ground truth," said University of Washington’s Donald Brownlee, the principal investigator for the so-called Stardust mission.

"We have some actual samples of the material that the solar system was formed from," he said.

Thursday’s launch was delayed nearly an hour due to cloudy skies over Cape Canaveral. Tracking cameras needed a clear view of the rocket’s climb to space in case the vehicle veered off-course and had to be destroyed by range safety officers.