Rocket carrying NASA asteroid probe blasts off from Florida

CAPE CANAVERAL, Fla. (Reuters) - A NASA space probe was launched aboard an Atlas 5 rocket from Florida on Thursday on an quest to collect samples from an asteroid and return them to Earth in hopes of learning more about the origins of life. The United Launch Alliance booster lifted off at 7:05 p.m. EDT (2305 GMT) from Cape Canaveral Air Force Station. Perched on top of the 19-story rocket was NASA’s robot explorer Osiris-Rex, built by Lockheed Martin to carry out the seven-year, $1 billion mission to and from the near-Earth asteroid Bennu. United Launch Alliance is a private partnership between Lockheed and Boeing . The 3,300-pound (1,500 kg) solar-powered probe is expected to take two years to reach its destination, a dark, rocky mass roughly a third of a mile wide and shaped like giant acorn orbiting the sun at roughly the same distance as Earth. Scientists believe Bennu is covered with organic compounds dating back to the earliest days of the solar system. Once it settles into orbit around Bennu in 2018, the Osiris-Rex probe will spend up to two more years mapping the asteroid's surface and taking inventory of its chemical and mineral composition. Scientists will ultimately select a promising site to sample and command Osiris-Rex to fly close enough to Bennu so that the probe's robot arm can touch the asteroid's surface. A sampling container will then release a swirl of nitrogen gas, which will stir up gravel and soil for collection. After gathering at least 2 ounces (60 grams) of material, Osiris-Rex will fly back to Earth, jettisoning a capsule holding the asteroid-sample container for a parachute descent and landing in the Utah desert in September 2023. (Reporting by Irene Klotz at Cape Canaveral; Editing by Steve Gorman and Tom Brown)