CAPE CANAVERAL, Fla. – Inside a laboratory in the Space Station Processing Facility at NASA's Kennedy Space Center in Florida, April Spinale, a payload integration specialist with Bionetics, and Ray Polniak, a quality assurance specialist with Dynamac, prepare vials for the Protein Crystal Growth 2 experiment for an acceptance leak test. The vials have been filled with clear water and will be put into a vacuum chamber to verify that the hardware is providing adequate containment for the liquids. Both are consultants for the Center for Advancement of Science in Space, or CASIS. The experiment is one of many that will be delivered to the International Space Station on the SpaceX-4 commercial cargo resupply mission. Kennedy's ISS Ground Processing and Research Project Office is providing the necessary laboratories, equipment, supplies and consumables for 61 principal investigators, including 17 from other countries, as they prepare their science experiments for flight. The SpaceX-4 flight is targeted to launch in September 2014. Photo credit: NASA/Dimitri Gerondidakis KSC-2014-3797

The International Space Station (ISS) is a habitable space station in low Earth orbit with an altitude of between 330 and 435 km (205 and 270 mi). It completes 15.54 orbits per day. Its first component launched into orbit in 1998, and the ISS is now the largest man-made body in low Earth orbit. The ISS consists of many pressurized modules, external trusses, solar arrays, and other components. ISS components have been launched by Russian Proton and Soyuz rockets, and American Space Shuttles. The ISS is a space research laboratory, the testing ground for technologies and systems required for missions to the Moon and Mars. The station has been continuously occupied for 16 years and 201 days since the arrival of Expedition 1 on 2 November 2000. This is the longest continuous human presence in low Earth orbit, having surpassed the previous record of 9 years and 357 days held by Mir. The station is serviced by a variety of visiting spacecraft: the Russian Soyuz and Progress, the American Dragon and Cygnus, the Japanese H-II Transfer Vehicle, and formerly the Space Shuttle and the European Automated Transfer Vehicle. It has been visited by astronauts, cosmonauts and space tourists from 17 different nations.

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