On October 23, 2007, the space shuttle Discovery lifted off with the Harmony module bound for the International Space Station. The delivery came during the STS-120 mission and marked a significant step in the orbiting outpost's expansion.
Harmony is a utility hub measuring 14 feet wide and 24 feet long, roughly the length of a minibus. It connects with the European Space Agency's Columbus module and Japan's Kibo laboratory, and it houses the crew quarters for the American astronauts.
The addition changed the scale of the station considerably. With Harmony installed, the orbiting complex went from about the size of a three-bedroom house to something closer to a five-bedroom house.
When astronauts first brought the module to the station, they attached it temporarily to the Unity node. After the shuttle departed, the crew used the station's robotic arm to shift the shuttle docking port out of the way at the Destiny module. That cleared space for Harmony to be berthed at its permanent location beside Destiny.
The mission mattered because it launched a new phase of station growth by providing a connecting hub for future modules. Before Harmony, the most recent new room added to the station had arrived in 2001, when Russia's Pirs docking module, which has since been discarded, was attached.
Originally known as Node 2, Harmony was the second NASA-led hub module for the station, following Unity, or Node 1. Italy-based Thales Alenia Space built it for NASA. The module carries five common berthing mechanisms, which serve as connection points for other station modules.
After the roughly two-week STS-120 flight, Harmony was relocated from its temporary berth at Unity to the forward port of NASA's main Destiny laboratory. From there it became the link for Europe's Columbus lab on the starboard side and Japan's large Kibo lab on the port side. Some of its ports have been used by visiting cargo ships, and a docking port on its roof lets visiting vehicles park there.
Inside, Harmony holds eight payload racks. Four are devoted to avionics, while the other four are used for either stowage or crew quarters. NASA's astronaut sleeping quarters are based in the module. The name Harmony was chosen through a public naming contest run by NASA.
