Astronauts on third spacewalk to prep new room

Feb 17, 2010, 13:10 GMT

   Washington - Astronauts on Wednesday completed external work on the installation of the orbiting laboratory's newest room.

   Nicholas Patrick and Bob Behnken, crew members of the visiting space shuttle Endeavour, completed a five-hour, 48-minute spacewalk at 0803 GMT, according to NASA.

   They were to hook up heating, cooling and data cables on the station's new Tranquility module. They also removed insulation from Tranquility's picture window and released bolts that hold covers over the windows that will provide a panoramic view of Earth.

   The Italian-made node makes the station more than 90 per cent complete after more than 12 years of construction. Tranquility will provide the permanent crew of the International Space Station (ICC) with more space and house life support and environmental control systems, a treadmill and other equipment.

   But perhaps the most anticipated part of Tranquility is the six- windowed cupola that will allow astronauts to operate robotic controls and get a 360-degree view, like a crane operator sitting in a cabin. Made of specially equipped glass that protect crew from solar radiation, the cupoloa will allow allow scientific observations and provide long-term astronauts with a much-need glimpse of home.

   The Endeavour and ISS crews were able to overcome glitches with covers on Tranquility to move the cupola to its permanent location earlier this week.

   The windows come equipped with shutters to protect them from passing space debris and will be closed when not in use. The panes are designed to be replaced in space if need be.

   Tranquility is about 7 metres long, with a 4.5-metre diameter and weighs approximately 18,000 kilogrammes. The cupola is 1.5 metres long, 3 metres in diameter and 1,880 kilogrammes.

   Endeavour is to spend an extra day at the ISS to allow astronauts more time to move oxygen and water systems into Tranquility. Endeavour is now set to land at Kennedy Space Centre in Florida on February 21.

   The US space shuttle, which is the only craft big enough to bring large components to the ISS, is to be retired later this year with just four more flight planned before September.