Watch Live: NASA Astronauts Start Spacewalk

NASA astronauts Steve Swanson and Rick Mastracchio have started a 2.5-hour spacewalk on Wednesday to install a spare backup computer aboard the International Space Station

The spacewalk started just before 10 a.m. ET when the crew switched their suits to battery power, signaling the start of the operation

The astronauts will be replacing a backup computer known as a Multiplexer/Demultiplexer (MDM), which failed on April 11. It "provides telemetry and commands to truss systems, solar alpha rotary joints and the Mobile Transporter rail car which rides along the truss structure," according to NASA, and both of the computers have been at the International Space Station for more than 10 years Read more...