The first mission to Pluto was launched into space Thursday on a 9 ½-year, 4.8 billion-kilometer journey to the only unexplored planet in the solar system and to study the zone of icy objects at the outer edges of the system. After two days of delays due to poor weather and a power outage, the Atlas 5 rocket, built by Lockheed Martin, lifted off from Cape Canaveral Air Force Station in Florida. Because of the distance to be traveled, the National Aeronautics and Space Administration's (NASA's) New Horizons probe is not expected to transmit data from Pluto until 2015. With an unprecedented five solid-fuel strap-on boosters, the rocket sent the tiny spacecraft into space faster than any object launched before. After boosts from two upper-stage motors, the probe is expected to travel at 58,000 kilometers per hour (kph). Next year, the spacecraft is expected to accelerate another 14,500 kph by bouncing off Jupiter's massive gravity field. Despite the gain in speed, it will take New Horizons over nine years to reach Pluto and its largest moon, Charon. A successful voyage to Pluto would complete an exploration of the planets started by NASA in the early 1960s with unmanned missions to observe Mars, Mercury, and Venus.
