NASA spacewalkers complete upgrade at Int'l Space Station

Two NASA astronauts on a spacewalk Tuesday completed a years-long project to upgrade the power system at the International Space Station. Bob Behnken and Chris Cassidy installed a final, new lithium-ion battery, adding to 23 of the new power cells that replaced 48 aging nickel-hydrogen power cells. The space station is powered largely by solar power stored in batteries that are accessible only from space. More

(Source: UPI.com - Jul 22)