Discovery put Harmony in orbit 19 years ago today

On October 23, 2007, Space Shuttle Discovery climbed away from the launch pad carrying a cargo the station had waited six years for: a new room. The STS-120 mission delivered Harmony, a utility hub built for NASA by Italy-based Thales Alenia Space and originally designated Node 2, to the International Space Station.

Harmony measures 14 feet wide and 24 feet long, about the length of a minibus. It carries five common berthing mechanisms, the connection points other station modules dock to. Inside, eight payload racks line the walls: four handle avionics, four hold stowage or crew quarters. The sleeping quarters for NASA's astronauts sit in this module. The name came from a public naming contest NASA ran.

The module's arrival changed the station's footprint. Before Harmony went in, the orbiting complex measured about the size of a three-bedroom house. After, it read closer to a five-bedroom house. The last new room to join the outpost had landed in 2001, when Russia's Pirs docking module attached; Pirs has since been discarded.

Astronauts first bolted Harmony to the Unity node as a temporary stop. After Discovery departed at the end of the roughly two-week flight, the crew swung the station's robotic arm to shift the shuttle docking port out of the way at Destiny, clearing the space Harmony needed. Harmony then moved to the forward port of NASA's Destiny laboratory.

From that berth, Harmony became the junction for the outpost's largest labs: Europe's Columbus module on the starboard side, Japan's Kibo laboratory on the port side. Some of its ports now take visiting cargo ships, and a docking port on its roof lets visiting vehicles park there. Unity, or Node 1, preceded it as the first NASA-led hub on the station.