school energy&environment

Orbiting stations

The first concept of an artificial satellite that could accommodate human life was born from the imagination of  writer, Edward Everett Hale. In his short story dated 1870, entitled “The Brick Moon”,  Hale imagined he would build a space station  that would orbit around the Earth, simply using some bricks.
Some time after, the literary fantasy gave room to science. In a series of articles dated 1950, the German scientist Verner Von Braun, proposed the project of a space station shaped like a wheel, that, due to its rotating movement, would allow the creation of artificial gravity within its structure. Braun’s idea inspired the American film director Stanley Kubrick in his film “2001: a space odyssey” in 1967.
However, for the theory to be put into practice, we will have to await 19 April 1971. This time it was the Russians’ turn. They were still disappointed for having lost the race to the Moon, and they successfully launched the space station Salyut 1, into orbit around the Earth.
This first type of station consisted of a single cylinder shaped module that offered very little comfort to the astronauts inside it, however it was possible to carry out experiments on the resistance, for long periods of time, of men in conditions of microgravity in the environment.
On 14 May 1973, NASA launched Skylab in space. It was 35 metres long and weighed 76 tonnes. Its internal diameter reached 6.7 metres, and therefore the available space was really enormous for its three inhabitants. Three crews alternated their stay aboard the Skylab in the period from May 1973 to February 1974.
Subsequently, in 1984, the President of the United States, Ronald Reagan, launched the project of the Space Station Freedom, a project in which also Europe with ESA, Canada and Japan were supposed to take part. Unfortunately the disaster of the Challenger (1986) forced NASA to stop, and the project was substantially slowed down. That same year, also, the USSR  completed the space station Mir (Peace). It was launched on 20 February 1986 and became the most complex structure ever to be realized.
Mir was the first space station of a modular type, in other words it consisted of various structures that were launched separately and assembled in space (PHOTO – 6SpEspSt_t). During the 15 year period in which it remained in orbit  (in fact, it was supposed to remain in orbit  for 5 years), over one hundred cosmonauts and astronauts, from at least twelve different countries, stayed aboard. It was made up of seven modules, designed so that they could be connected to the station in various manners,  to adapt  to the requirements of the different missions.
At the start of the 90s, the Government of the United States also involved the European   Russian, Canadian and Japanese space agencies in the project of a space station. The project was presented in 1993 and the station was called Alpha. In the official documents it was then indicated as ISS (International Space Station). At present  sixteen nations are involved: USA,  Russia, Japan, Canada, Brazil, Belgium, Denmark, France, Germany, Italy, Holland, Norway, Spain, Sweden, Switzerland and the United Kingdom.
ISS, like Mir, is a modular satellite  that rotates around the Earth on a low orbit at an average height of 400 km, just above the denser layers of the atmosphere. It completes an orbit in approximately 90 minutes, and it is inclined more than 50 degrees on the equator, that is defined so that ISS can be reached from the launching bases of almost all the space areas in the world.
The International Space Station is a large scientific laboratory, and it includes one European laboratory, the Columbus, two American laboratories, one Japanese and three Russian laboratories. Here new technologies are experimented, that may be used again for space applications in the future or may turn out to be useful on the Earth to improve everyday life.