Snapshots from Atlas 5 launch

United Launch Alliance teams at Cape Canaveral hoisted a Centaur upper stage on top of an Atlas 5 rocket Friday at launch pad 41, completing the initial build-up of the launch vehicle slated to carry Boeing’s Starliner crew capsule into space in December on an unpiloted test flight to the International Space Station.

NASA’s Advanced Composite Solar Sail System (ACS3) will test materials and a deployable system for a solar sail-style propulsion system. Liftoff from New Zealand happened at 10:32 a.m. NZT on April 24 (6:32 p.m. EDT, 2232 UTC on April 23).

United Launch Alliance and SpaceX recently won contracts worth $739 million to send six missions into orbit for the U.S. military, and the Air Force has announced a new title for its flagship launcher program, dropping “expendable” from the name in a new era of reusable rockets.