Shuttle Atlantis unwrapped ahead of public debut

A SpaceX Falcon 9 rocket sporting human-rating upgrades such as new composite pressurant tanks briefly ignited its nine Merlin engines Thursday afternoon on a launch pad at NASA’s Kennedy Space Center in Florida, and SpaceX later declared the pre-launch milestone complete in preparation for a critical test flight with a commercial crew capsule as soon as late February.

In one of its final preflight tests, a SpaceX Falcon 9 rocket ignited at pad 39A in Florida for several seconds Thursday, ramping up to full throttle in an end-to-end checkout of the booster before liftoff next week on a space station resupply flight.

NASA is sending into orbit Monday night a spacecraft to test a safer type of rocket fuel, an ultra-precise atomic clock that could change the way missions navigate in deep space, and an experiment to examine the resiliency of electronics to radiation.