Video: Take a virtual ride on the Atlas 5 launch pad emergency ziplines

NASA has extended development agreements with SpaceX and Sierra Nevada Corp. past a March 31 deadline, giving the companies more time to complete delayed tests on commercial spacecraft intended to one day ferry astronauts into space.

An experiment-carrying, reusable mini space shuttle operated by the U.S. Air Force will be boosted into Earth orbit Wednesday atop a United Launch Alliance Atlas 5 rocket.

The first launch of Boeing’s Starliner space capsule aboard a United Launch Alliance Atlas 5 rocket has been delayed to Dec. 19, officials announced Tuesday.