Atlantis' five astronauts on Thursday successfully completed a test that simulated an engine start and cut off moments before liftoff, NASA said. The shuttle is scheduled for a secret military mission in mid-July. NASA spokeswoman Lisa Malone said the two-day drill went smoothly. The countdown clock was stopped at four seconds before the mock liftoff. On Monday, Atlantis was moved from the hangar to the launch pad previously occupied by Columbia. Columbia was returned to the hangar last week for repair of a hydrogen leak that has delayed the shuttle's astronomy mission until at least mid-August. The National Aeronautics and Space Administration plans to conduct a special tanking test on Wednesday, partly filling Atlantis' external tank with super-cold liquid hydrogen to make sure there are no leaks. A similar test was performed on Columbia a week after a hydrogen leak was detected during fueling for a May 30 launch. A launch date for Atlantis will be set at the conclusion of a two-day flight readiness review on June 28 and 29.
