NASA said on Friday it would revamp plans for a spacewalk outside the International Space Station after a cable that supplies power, oxygen, cooling water and communications to one of the astronaut's spacesuits started to leak.
The spacewalk had been scheduled to begin at 8 a.m. EDT (1200 GMT), the U.S. space agency said.
Station commander Peggy Whitson, a veteran with eight previous spacewalks, and rookie flight engineer Jack Fischer, who will be making his first outing, shared a second good cable known as an umbilical as they prepared to leave the station's airlock, said mission commentator Rob Navias.
The highest-priority tasks for the spacewalk, which had been slated to last 6 1/2 hours, are to replace a 200-pound electronics box that routes commands and data to experiments, and to install equipment to troubleshoot a cooling system problem with the station's $2 billion dark matter detector.
Americans Whitson and Fischer also plan to install a wireless communications antenna and a high-definition TV camera, and to attach a debris shield onto an exposed docking port that is being prepared for commercial space taxis under development by Space Exploration Technologies and Boeing Co.