Shuttle Atlantis unwrapped ahead of public debut

Nine Merlin main engines at the base of a SpaceX Falcon 9 rocket fired at launch pad 39A Saturday, passing a major test before the company’s next launch, a secretive mission slated for liftoff Wednesday night.

Nine Merlin main engines on a SpaceX Falcon 9 rocket ignited at 12 p.m. EDT (1600 GMT) Friday, April 17, during a hold-down test-firing on launch pad 39A at NASA’s Kennedy Space Center in Florida.

Thirty years after the space shuttle Challenger disintegrated in the clear, cold sky high above Cape Canaveral, the commander’s widow no longer feels anger at NASA and the management missteps and schedule pressure that kept the orbiters flying despite a fatal flaw in their solid-fuel boosters.