After liftoff, it’s Pluto or bust

CAPE CANAVERAL, Fla. – After two days of delays, NASA’s New Horizons spacecraft executed a picture-perfect liftoff Thursday on a nine-year journey to Pluto, the last unexplored planet in our solar system.

The spacecraft, the first American probe since 1977 to visit a new planet, launched at 2 p.m. EST. “The spacecraft is where it needs to be, going at the right speed, in the right direction,” launch director Omar Baez said.

New Horizons is the fastest craft ever built by the space agency, designed to reach a top speed of 47,000 mph next year by using Jupiter’s gravity to slingshot itself into the outer solar system. It is expected to reach Pluto in July 2015.

Launching in January was important for New Horizons to keep its appointment with Jupiter next year.

It was scheduled to launch Tuesday, but high winds forced a one-day delay. The mission was scrubbed the next day when a power outage struck the Applied Physics Laboratory at Johns Hopkins University, where mission control is located. Clouds on Thursday delayed the launch by almost an hour.

Continued delays would have forced the craft to go straight to Pluto, costing the mission an extra three years of travel time.

Plumbing the mysteries of Pluto will help scientists understand why the planets formed where they did. New Horizons also will give researchers a close-up look at the Kuiper Belt, a huge region of icy planetoids that lies beyond Neptune.

Although it was at one time thought to be a sparse junkyard of castoff planetary parts, so many new objects have been found recently in the Kuiper Belt that scientists are speculating it may be the remains of a giant 10th planet torn apart by the forces of the inner planets.

At a news conference following the launch, Alan Stern, the mission’s principal investigator, revealed that, besides seven scientific instruments, New Horizons is carrying an unusual piece of cargo: the ashes of Clyde Tombaugh, the astronomer who discovered Pluto in 1930.

Tombaugh, whose widow attended the launch, is the only American so far to have discovered a planet. That may change soon if the International Astronomical Union certifies Sedna, an object discovered last year by a team at the California Institute of Technology, to be a planet. Sedna is larger than Pluto.