Marking the grand finale of the 14-day Endeavor mission, astronauts Wednesday opened the shutters on the new observation deck of the International Space Station (ISS); thereby uncovering "absolutely spectacular" views of Earth from inside the sophisticated foyer of windows.

The much-awaited occasion came when the shutter round central window, the biggest flown in space thus far, was cranked open by the astronauts exposing the first panoramic view of the Earth 200 miles below.

The finishing touches to the dome-shaped observation desk - with six trapezoid-shaped windows encircling it, and the central window - were applied by astronauts Robert Behnken and Nicholas Patrick on Tuesday, while undertaking the last of Endeavor's three scheduled spacewalks.

The Italian-manufactured dome - which is 5 feet tall and almost 10 feet in diameter - will provide matchless viewing experience to the astronauts, as it has been specifically designed to offer a 360-degree view of the Earth and outer space, along with the ISS itself.

Terming the spectacular sight from the$27 million lookout as "absolutely incredible," the ISS commander Jeffrey Williams said: "As expected, the view through window seven is absolutely spectacular. When we have the others around it open, it will give us a view of the entire globe."

Meanwhile, in a congratulatory call to the astronauts, Mission Control said that with the installation of the phenomenal window, the ISS is set for a momentous change!