On Dec. 6, 1998, astronauts on the space shuttle Endeavour officially began the construction of the International Space Station.

Mission STS-88 was the first shuttle mission to the space station. It brought along the first American component of the orbiting laboratory, an 18-foot-long module called the Unity Node, or Node 1, By the time the Unity node went to space, Russia's first space station component, the Zarya module, had already been in orbit for a couple weeks. So the STS-88 crew brought Unity to Zarya and connected the two components in orbit.