Snapshots from Atlas 5 launch

The United Launch Alliance Atlas 5 rocket stands poised for flight with the Air Force’s X-37B spaceplane and a batch of CubeSats including the LightSail. The rocket was rolled to Complex 41 on Tuesday in preparation for launch on Wednesday.

Follow the unclassified portion of the Atlas 5 rocket’s ascent to space from California’s Vandenberg Air Force Base launch site with the U.S. National Reconnaissance Office’s NROL-79 satellite payload. Launch is scheduled for Wednesday at 9:50 a.m. local time (12:50 p.m. EST; 1750 GMT).

Two astronauts floated outside the International Space Station early Friday for the first of four planned spacewalks to wrap up a complex multi-year job to replace 48 aging batteries in the lab’s solar power system with 24 more powerful lithium-ion units.