Photos: Atlas 5 rocket aims for International Space Station

United Launch Alliance and Boeing teams worked through the weekend on closeouts of the Starliner crew capsule, inspections and final outfitting of the Atlas 5 rocket. A launch readiness review Tuesday approved the continuation of final preparations for liftoff from Cape Canaveral Friday of the first Starliner spacecraft on an unpiloted test flight to the International Space Station.

What began as a concept scribbled on a cocktail napkin in a Tucson bar 12 years ago — sending a spacecraft to an asteroid and retrieving a pristine sample to bring back to Earth for study — becomes reality Thursday with the launch of NASA’s OSIRIS-REx mission.

Astronauts Peggy Whitson and Jack Fischer put on spacesuits Friday and headed outside the International Space Station for several repair and maintenance tasks, but the duo only completed part of their originally planned work after a leaky cooling umbilical delayed the start of their spacewalk.