Photos: Atlas 5 rolls out for Friday launch to GPS constellation

NASA and Boeing have awarded Aerojet Rocketdyne widely-anticipated contracts to restart the production of simplified shuttle-era rocket engines for the heavy-lift Space Launch System and supply the propulsion system for the CST-100 Starliner commercial crew capsule, officials announced this week.

United Launch Alliance technicians positioned the first stage for the next Atlas 5 rocket on a mobile launch platform Friday at Cape Canaveral, a key step in preparations for an October mission that will debut a new solid-fueled booster design.

Astronauts Jeff Williams and Kate Rubins ventured outside the lab complex Friday for a long-awaited spacewalk to attach a new docking mechanism, the first of two that will be used by U.S. crew ferry ships being built by Boeing and SpaceX to carry astronauts to and from the outpost, ending NASA’s sole reliance on Russian Soyuz spacecraft.