Live coverage: SpaceX supply ship returns to Earth

NASA expects to spend some $5 billion underwriting development of commercial spacecraft built by Boeing and SpaceX to carry astronauts to and from the space station, ending reliance on the Russians for crew flights and lowering the average cost per seat to around $58 million.

The two structural elements of Orbital ATK’s OA-7 Cygnus space freighter were delivered to Kennedy Space Center for final assembly, the packing of cargo and launch to the International Space Station.

The four RS-25 engines at the bottom of NASA’s first Space Launch System core stage shut down about a minute into a ground test-firing Saturday that was supposed to last more than eight minutes.