Orbital Sciences Corporation (NYSE: ORB) announced Alliant Techsystems (NYSE: ATK) and the U.S. Air Force's Arnold Engineering Development Center (AEDC) successfully ground tested the second stage rocket motor of the company's Taurus® II launch vehicle at AEDC in Tennessee. The solid-fuel CASTOR® 30 motor, which is supplied to Orbital by ATK Space Systems of Magna, Utah, was test fired for approximately 150 seconds, producing 72,000 lbs. of maximum thrust.  In order to accurately test the motor performance, the static fire test was conducted using a vacuum chamber specially designed to simulate upper atmospheric conditions, as the motor is designed to ignite at altitudes in excess of 100,000 feet.