One of the conical adapters will attach Unity to the Zarya, while the other will serve as a docking port for the Space Shuttle. The Unity node with the two mating adapters attached, the configuration it will be in for launch, is about 36 feet long and weighs about 25,600 pounds. Unity also will be outfitted with an early communications system that will allow data, voice and low data rate video with Mission Control, Houston, to supplement Russian communications systems during the early station assembly activities. Nodes 2 and 3 will be slightly longer than the Unity node, measuring almost 21 feet long, and each will hold eight standard space station equipment racks in addition to six berthing ports. ESA is building the two additional nodes as partial payment for the launch of the ESA Columbus laboratory module and other equipment on the Space Shuttle.
Unity holds four equipment racks.
The International Space Station will allow scientists to conduct long-duration experiments and research in the environment of space. It is the largest peacetime scientific mission in history and combines the resources of 16 nations. When completely assembled in 2004, the International Space Station will have a mass of more than 1 million pounds and provide more than 46,000 cubic feet of pressurized living and working space for up to seven astronauts and scientists.