The International Space Station (ISS) is a research facility currently being assembled in space. The on-orbit assembly of ISS began in 1998. The ISS has been continuously inhabited since the first resident crew entered the station on November 2, 2000, thereby providing a permanent human presence in space. Early crew members all came from the Russian and U.S. space programs. The ISS was also the destination of the first five space tourists. At an estimated cost of $157 billion for the ISS project from its start until the program will end in 2017, the ISS is the most expensive object ever built by humankind. This is dwarfed by the price of the Iraq War with the total cost to the U.S. economy estimated at $3 to 5 trillion in five years.
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