Two astronauts aboard the International Space Station have completed a space walk to install a new science experiment ahead of the scheduled launch of the space shuttle Discovery.
The American and Russian astronauts completed their work outside the station more than an hour ahead of schedule. Commander Mike Fincke and Yuri Lonchakov installed a new European experiment that is intended to expose seeds and other organic materials to conditions outside of the space station. They also adjusted equipment for a micrometeoroid experiment and conducted a photographic inspection of the Russian segment of the station.
A Russian translator monitored the communications between space station controllers in Moscow and the two astronauts as they completed their space walk.
"OK guys, we have a go to close the EVA [extra vehicular activity] hatch," said the mission controller. "Michael, you can try to do that. OK space [station], goodbye for now."
Astronaut Sandra Magnus is spending her final days aboard the space station before the arrival of Discovery, which is due to launch late Wednesday. Magnus is scheduled to return to Earth aboard the shuttle and be replaced by Koichi Wakata.
The 14-day Discovery mission is intended to deliver a new solar array and a support girder to the space station. NASA officials delayed the launch several times to resolve problems with fuel control valves in the shuttle's main engine. Engineers replaced the valves and officials said Monday that all shuttle systems are good for launch.
Forecasts show good weather at the Kennedy Space Center in Florida for an evening liftoff.