Astronauts unveil phenomenal new window on world

the curtains on the bay window to the world," astronaut Kay Hire called out to the spacewalkers.

"I look forward to the view from inside," Patrick said.

Mission Control wanted the shutters opened while the spacewalkers were still floating outside so the two men could intercede if something jammed. Behnken and Patrick stayed a safe 10 feet or more from the windows while the shutters were raised. The last thing NASA wanted was to have one of them inadvertently kick a window or bang it with a tool bag.

The observation deck is part of Tranquility, a more than $380 million addition. Space shuttle Endeavour delivered the European compartments last week.

The Italian-built dome — 5 feet tall and nearly 10 feet in diameter — is designed to offer sweeping 360-degree views of the home planet and outer space, as well as the space station itself. It's not just for the crew's viewing pleasure; a robotic work station will be installed early Thursday, providing direct views for astronauts when they operate the station's big mechanical arm.

Six trapezoid-shaped windows encircle the dome. In the middle is the circular window.

During normal operations, the space station crew will be able to keep the round window unshuttered most of the time, along with a couple others. But the windows facing along the direction the outpost is orbiting will need to be closed, except during robotic operations, to protect the fused silica glass against micrometeorite strikes. Each window has four panes.

The shutters swung open when the spacewalkers were back inside. The nearly six-hour excursion ended a little early because of the risk of elevated carbon dioxide levels in Behnken's suit; he was fine, but flight controllers did not want to take any chances.

Endeavour ...