Spacewalking astronauts briefly lose ground link

Spacewalking astronauts outside the International Space Station lost touch with ground controllers for 33 minutes when a storm knocked out their radio link.

Spacewalkers Danny Olivas and Nicole Stott kept working outside the International Space Station during the communications blackout under the watchful eyes of their crewmates.

"This is no safety of flight issue," said NASA commentator Rob Navias from Mission Control in Houston, which gets its satellite feeds from the shuttle and space station via a ground antenna in White Sands, New Mexico.

The New Mexico station was using a relay through Guam, which was cut off due to a storm, Navias said. The spacewalk, the first of three scheduled for shuttle Discovery's mission, was scheduled to end at 0419 GMT.

Olivas and Stott were about halfway through their planned 6.5-hour spacewalk when the communications blackout occurred.

They had already finished their main task of the outing, disconnecting a spent tank of ammonia. A replacement tank of coolant is scheduled to be installed by Olivas and European Space Agency astronaut Christer Fuglesang during the mission's second spacewalk on Thursday.

Discovery arrived at the station on Sunday to deliver more than seven tonnes of food, supplies, equipment and spare parts to the $100 billion orbital outpost, a project of 16 nations that is nearing completion after more than a decade of construction.

The shuttle is due back at the Kennedy Space Center in Florida on September 10.