Photos: Atlas 5 rolls out for launch

The U.S. Government Accountability Office has denied a protest filed by Sierra Nevada Corp. challenging NASA’s selection of competitors Boeing and SpaceX to build commercial human-rated space capsules to fly astronauts to the International Space Station.

Follow the Atlas 5 rocket’s ascent into orbit from Cape Canaveral’s Complex 41 launch pad with the Orbital ATK Cygnus resupply ship for the International Space Station. Launch is scheduled for Thursday at 5:55 p.m. EST (2255 GMT).

A robotic arm extended from NASA’s OSIRIS-REx spacecraft briefly contacted the rugged surface of asteroid Bennu Tuesday to gobble up pristine samples, a climactic moment in the $1 billion mission to bring asteroid material back to Earth in 2023.