In 2011, the last rivet should be in place on the International Space Station, a $100 billion project under construction in outer space since 1998. Once completed, the 16-nation orbiting lab will contain more than 33,000 cubic feet of livable space, weigh 925,000 pounds and stretch 361 feet from end to end, which is the length of a football field including the end zones. Check out this and six more colossal engineering projects.