An unmanned spacecraft carrying 6,300 pounds of supplies and science experiments caught up Saturday morning with the International Space Station as it flew 252 miles above the Indian Ocean. The Cygnus spacecraft, made by Dulles-based Orbital ATK, had launched late Tuesday from Cape Canaveral on its journey to the orbiting laboratory. Flying at more than 15,000 mph, the spacecraft was captured by the station's robotic arm at 6:51 a.m. Eastern in what a NASA official called a "textbook rendezvous." The spacecraft was launched atop an Atlas V rocket that Oribtal ATK hired from the United Launch Alliance, the joint venture between Lockheed Martin and Boeing.