International Space Station makes discoveries impossible anywhere else

It may be 350 kilometres above earth and a place that only a privileged few will ever visit, but the International Space Station (ISS) is crucial to advances in science, health and technology, experts say.

Last month, Nasa said the life of the US$100 billion ISS would be extended by four years, or until at least 2024, allowing for more global research and scientific collaboration.

John Holdren, a senior White House adviser on science and technology, hailed the space station, which was mainly built with United States money, as "a unique facility that offers enormous scientific and societal benefits".

"The Obama administration's decision to extend its life until at least 2024 will allow us to maximise its potential, deliver critical benefits to our nation and the world and maintain American leadership in space," Holdren said.

The orbiting outpost, which was launched to fanfare in 1998, has more living space than a six-bedroom house and comes complete with internet access, a gymnasium, two bathrooms and a 360-degree bay window offering spectacular views of earth.

It is made up of various working and sleeping modules, and extends about 100 metres, making it four times bigger than the Russian space station Mir and about five times as large as the US Skylab.