ABOVE: Janet L. Kavandi, STS-104 mission specialist, connects cables and hoses from the newly installed Quest Airlock to Unity Node 1. Other STS104 and Expedition Two crewmembers are visible in the background working in the airlock. RIGHT: This image of the International Space Station and the docked Space Shuttle Endeavour, flying at an altitude of approximately 220 miles, was taken by Expedition 27 crewmember Paolo Nespoli from the Soyuz TMA-20 following its undocking on May 23, 2011 (USA time). The pictures taken by Nespoli are the first taken of a shuttle docked to the International Space Station from the perspective of a Russian Soyuz spacecraft. Onboard the Soyuz were Russian cosmonaut and Expedition 27 commander Dmitry Kondratyev; Nespoli, a European Space Agency astronaut; and NASA astronaut Cady Coleman. Coleman and Nespoli were both flight engineers. The three landed in Kazakhstan later that day, completing 159 days in
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space. This was the final mission of Endeavour.
Space Operations Center in low-Earth orbit, serviced by Space Shuttle orbiters. The ISS configuration can be traced to early designs of the Space Station Freedom concept, developed during the 1980s, and the American-built segments of the ISS truss structure, its solar arrays, and thermal radiators – along with many of the American, European, and Japanese modules – underwent rigorous integration testing at the Space Station Processing Facility, a three-story, 457,000-square-foot building at the Kennedy Space Center, Cape Canaveral, Florida. Most of the U.S. modules, and the ISS Environmental Control and Life Support System, were developed at the Marshall Space Flight Center in Huntsville, Alabama. Like their Russian counterparts, American astronauts have participated in every one of the ISS’s first 56 expeditions; 51 U.S. astronauts have served aboard the station so far, and more than 140 Americans have visited the station. The station’s basic structural and functional elements – the 12 segments of the 356-foot-long integrated truss assembly, electric power system, and guidance, navigation, and control system – were designed and built in the United States by lead contractor Boeing. The truss assembly provides attachment points for modules, solar arrays, thermal control radiators, external payloads, utility lines, and the rails for the Mobile Servicing System. The first American module to be flown to the station was the Unity (Node 1) connector, a six-port cylinder berthed via a Pressurized
Mating Adapter to Zarya’s forward port that provides a link between the Russian and American Orbital Segments. The first of the three connecting modules, Unity, is shorter than the other two nodes, and in addition to providing passage for crewmembers between the Russian and American segments, Unity carries essential resources such as environmental control systems (i.e., air quality and temperature control), electricity, data, and fluids. The 15-foot-long Unity contains about 50,000 mechanical items, 216 gas and fluid lines, and 121 electrical cables. The U.S. laboratory module, Destiny, is berthed to Unity’s forward port. The primary research laboratory for U.S. payloads, the 28-footlong Destiny has a total of 24 racks (13 scientific payloads; 11 systems). Destiny’s experiments include investigations related to human life science, materials research, Earth observations, and commercial applications. The science equipment aboard Destiny includes the Minus Eighty Degree Laboratory Freezer for the ISS (MELFI). Before the arrival of the Cupola, the station’s best views of Earth could generally be found at Destiny’s 20-inch nadir window, where, in 2010, the Brazilian-made Window Observational Research Facility, or WORF, was installed to enable photographic research and imaging projects in the fields of geology, agriculture, ranching, and environmental or coastal changes. Destiny was named a U.S. National Laboratory in NASA’s 2005 Authorization Act. The Quest Joint Airlock, a pressurized module designed to host spacewalks using both American and Russian space suits, is berthed to Unity’s starboard port. The primary airlock for the ISS, the Quest Airlock consists of two compartments: the equipment lock, for suit maintenance and refurbishment, and the crew lock, which is fitted with the hatch for spacewalk exit and entry. Assembly of the ISS in low-Earth orbit was made possible by the cargo-lift capabilities of the Space Shuttle orbiters Discovery, Atlantis, and Endeavour. From the launch of Unity (Node 1) on Dec. 4, 1998, to the program’s final flight, Atlantis’s delivery and return of the MPLM Rafaello in July 2011, the Space Shuttle played a critical role
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