PROMONTORY, Utah (AP) — The Utah company that makes booster rockets for the space shuttle has conducted its final ground test.Thursday’s successful test by Alliant Techsystems and NASA at Promontory signals the end of the space shuttle program. Company officials say it went smoothly and that about 5,000 people showed up to watch.The test – with the 126-foot rocket anchored horizontally to the ground – ignited more than a million pounds of propellant in a split second and took about two minutes to burn off.The rocket is the same kind that will help lift the space shuttle in its last four scheduled missions.Clearfield-based ATK Space Systems has laid off 970 workers in Utah since October, citing the phase-out of the space shuttle and the Minuteman III ballistic missile programs.