The International Space Station (ISS) has turned 15 years old. The ISS is a project where astronauts are able to work in space for months at a time. It opened for the first time on December 10th, 1998. Bob Cabana was the commander of the space shuttle mission that put the first modules of the International Space Station together, according to USA Today. Cabana worked with Russian crew mate Sergi Krikalev on the project. Today the International Space Station is around half the size of a football field and weighs over one million pounds. There are 15 national partners on the ISS along with NASA.