The International Space Station is almost done. Astronauts on board the current space shuttle Endeavour completed the first of three spacewalks to install the last major component of the ISS: the Tranquility module. Its huge windows will offer ISS residents 360-degree view of space, the station, and our home world.

The U.S. Tranquility module — shaped like a soda can — is the last major American addition to the station, now 98% complete. Its placement completes 11 years of U.S. construction work on the outpost, which the United States has spent more than $50 billion building [USA Today]. An Italian team designed the module’s magnificent dome, which measures 10 feet in diameter. Seven windows provide the panoramic view.

With Tranquility’s power hookup now in place, astronauts will install the plumbing during their second space walk. Tranquility will house functional items like exercise equipment, toilet, and water recycling system. But there’s another reason the astronauts are keen to see it open its huge windows. NASA readily acknowledges the observation deck and its 360-degree views will improve the quality of life aboard the orbital outpost, where astronauts spend six months at a stretch [AP].

Plus, it’s just nice to be approaching the finish line, especially with only a few shuttle flights remaining before they go into retirement this year, and the future of human spaceflight uncertain in the United States. “What this mission symbolizes, I think, in a lot of ways, it’s like the Transcontinental Railroad. And our flight is kind of like putting the Golden Spike in the Transcontinental Railroad,” shuttle pilot Terry Virts said [USA Today].

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Image: NASA