The International Space Station (ISS) is a research facility that is being built in low orbit around the Earth. The space station is so large that it can actually be seen with the naked eye and is the largest space station built to date. The International Space Station is 73 by 108.5 meters and will weigh 344,378 kilograms upon completion. The ISS is scheduled to be finished in 2011. Since autumn of 2009, there has been a constant human presence in space with the crew of the space station.
It is an international project with a number different countries involved. The contributing space agencies are NASA, the Russian Federal Space Agency, the Japanese Aerospace Exploration Agency, the European Space Agency, and the Canadian Space Agency. Although the European Space Agency (ESA) is involved, there are only 10 countries in the agency involved: Belgium, Denmark, France, Spain, Italy, Germany, the Netherlands, Norway, Switzerland, and Sweden. Brazil is also contributing to the construction of the space station.
The in-space construction of the space station began in 1998 after the countries signed the Space Station Intergovernmental Agreement (IGA). Brazil did not sign the treaty, but they made a contract with NASA to fly one Brazilian astronaut to space in exchange for contributing hardware to the project. A number of Space Shuttles have been sent to the ISS in order to switch crews, resupply, work on construction, and make repairs. Modules of the space station are sent up using Space Shuttles or rockets.
A crew of at least three lives on the space station at all times. Originally, the astronauts and scientists from various countries are pulled to man the space station. Countries that have contributed more to the space station receive more time in space. Russia has more crew members there because they run the Russian part of the station. The International Space Station is a record setting project with more than 180 different people visiting it and over 100 spacewalks taken outside the station.
The main purpose of the ISS is scientific research and many projects are currently underway. The effect on the human body of living in space for a long period of time is one area being researched with scientists looking specifically at muscle atrophy and bone loss as well as the shift of bodily fluids. Other areas of research include growing cells in zero gravity and testing the effect of zero gravity on plants, animals. With a constant crew on the space station, scientists can run and monitor numerous experiments.
Astronomy Cast has an episode on the space station’s orbit.