Photos: Atlas 5 rocket aims for International Space Station

Two astronauts floated outside the International Space Station Monday for NASA’s third spacewalk in less than three weeks for more battery replacement work and installation of cables.

NASA expects to select commercial contractors to resupply the International Space Station in September, three months later than the agency’s previous timetable under a competition for cargo deliveries beginning in 2018.

NASA and Northrop Grumman managers at the Kennedy Space Center decided Tuesday to press ahead with final preparations to launch a NASA scientific research satellite early Wednesday aboard an air-launched Pegasus XL rocket off Florida’s east coast.