World's Largest Space Window Headed to Orbit
An artist's concept of the new space station Cupola.
Credit: NASA

Talk about a room with a view. The largest space window ever built will launch aboard NASA's shuttle Endeavour on Sunday, part of a new seven-portal observation deck for the International Space Station.

The new addition, called the Cupola, will offer astronauts a panoramic view of space and Earth below them.

"Cupola is going to be probably the best set of windows that?s ever flown in space on any program in the history of spaceflight," said mission specialist Nicholas Patrick, one of six astronauts delivering the Cupola to the station on Endeavour.

The shuttle?s STS-130 flight, commanded by veteran spaceflyer George Zamka, is scheduled to blast off at 4:39 a.m. EST (0939 GMT) from NASA's Kennedy Space Center in Cape Canaveral, Fla.

The 1.6 ton Cupola stretches 9.7 feet (3 meters) wide, and is nearly 5 feet (1.5 meters) long. Its circular top window is 31.5 inches (80 cm) in diameter, making it the largest window ever flown in space.

The structure is set to be installed underneath the new Tranquility module, a soda-can shaped room also set to fly aboard Endeavour. The Cupola cost an estimated 20 million Euros, or $27.2 million.

"We will have the most spectacular view of the Earth anyone?s ever had from the inside," mission specialist Stephen Robinson said in a NASA interview.

A room with a view

The dome's purpose isn't just to provide a great vista, though. It will offer a view of incoming spacecraft to the space station to help with docking and rendezvous, and astronauts can look out the windows when controlling the station's robotic arm.

"We?ll be able to move the robotic arm control station into that Cupola area, consider it like a bay window, and be able to have an actual out-the-window view to operate the robotic arm," said mission specialist Kathryn Hire. "As we operate today on the International Space Station for the robotic arm, we?re using all external camera views. We have no direct window views to operate the arm."

The seven windows have been specially outfitted with shell-like aluminum shields that can be closed over them when they are not in use to protect the glass from damage by tiny meteoroids and orbital debris.

Even when the shutters are open, the windows will have a measure of protection from an external pane of glass specially designed to act as a barrier against debris. If a window is damaged by space junk, it can be replaced in orbit. It?s a difficult repair, but not impossible, mission managers said.

The Cupola's windows are not science-grade, however ? their clarity is not of quite as high quality as the windows in the station's Destiny module, for example, so many of the Earth observation science photos will still be taken from that room.

Window on the world

The dome's role as a relaxing hangout is an important aspect of its design, too.

"Crews tell us that Earth gazing is important to them," said Julie Robinson, space station program scientist at NASA's Johnson Space Center in Houston. "The astronauts work hard up there and are away from their families for a long time. Observing the Earth and the stars helps relax and inspire them."

Though they will be part of the U.S. segment of the space station, the Cupola and the new Tranquility module were both built by the European Space Agency as a contribution in payment for America's role transporting European astronauts to and from the station on space shuttles.

"It is our great privilege to bring up Node 3 and the Cupola, and these are the last U.S. major components that are coming up to the International Space Station," Hire said.

SPACE.com is providing complete coverage of Endeavour's STS-130 mission to the International Space Station with Managing Editor Tariq Malik in Cape Canaveral and Staff Writer Clara Moskowitz in New York. Click here for shuttle mission updates and a link to NASA TV. Live coverage begins at 11:30 p.m. ET.