Nearly 15 years after her first space launch, NASA astronaut Peggy Whitson has now spent more time off-planet than any other American, at more than 534 days. Whitson, 57, is a biochemist who has twice commanded the International Space Station.

The SpaceX Falcon 9 NROL-76 rocket launch from Kennedy Space Center is slated for Sunday, April 30, from the historic pad 39A.

Launch window will open at 7 a.m. ET.

The SpaceX Falcon 9 rocket will launch a classified spacecraft payload for the U.S. National Reconnaissance Office (NRO).

It will be SpaceX’s first launch for the NRO.

The launch was delayed from April 16.

Updated 7:55 p.m. ET

The most expensive part of doing business in outer space is getting there. The private space flight company SpaceX thinks it can change all that, and Thursday's successful reuse of a rocket was a big test of its business model.

SpaceX launched a communications satellite from the Kennedy Space Center in Florida using a rocket stage that had already been to space and back. SpaceX is betting that this kind of recycling will lower its costs and revolutionize space flight.

Updated at 3:30 p.m. ET

Moon Express

Cape Canaveral company Moon Express got $45-million to fund landing their spacecraft on the moon. And a shot at winning the Google Lunar XPRIZE.