The first walk was scheduled to start at 7:45 a.m., Saturday by Barry Wilmore and Terry Virts. They plan to install power and data cables which are needed for new docking mechanisms aboard the ISS.
The astronauts will also install antennas which will be part of a new communications system, officials said.
NASA engineers had to troubleshoot several issues including corrosion that was found in spacesuit fan assemblies before starting the space walks. The walks were delayed until the issues could be fixed.
The first space walk is expected to last six hours.