A space capsule loaded with comet dust was barreling toward Earth after being released by its mother ship late on Saturday following a seven-year, 2.9 billion-mile (4.5 billion km) journey to recover materials formed at the dawn of the solar system, according to Reuters. NASA's Stardust mission, which will allow scientists to study comet samples for the first time, ends early Sunday when the 100-pound (45 kg) capsule is expected to land at the U.S. Air Force Utah Test and Training range at 3:12 a.m. local time (5:12 a.m. EST/ or 1012 GMT). NASA scientists and engineers at the remote military outpost were nervous but upbeat as they awaited the vessel's return, according to one Stardust team member. "There is some tension," said Chris Jones, director of solar system exploration at NASA's Jet Propulsion Laboratory. "There are parts of the system that have never been used before and they represent the unknown." In what was likely to assuage some of those concerns, the Stardust spacecraft severed the umbilical cables between it and the capsule as scheduled at 9:56 p.m. PST (12:56 a.m. EST on Sunday/0556 GMT). One minute later, springs on the craft pushed the capsule away. It is expected to enter the Earth's atmosphere roughly four hours later at a speed of 28,860 miles per hour (46,440 km per hour), the fastest of any man-made object on record. The descent may be visible from the ground in northern California, Oregon and Nevada.
