It may be 350 kilometres above Earth and a place that only a privileged few will ever visit, but experts say the International Space Station is crucial to advances in science, health and technology.
Earlier this month, NASA said the life of the $US100 billion ($A114.46 billion) ISS would be extended by four years, or until at least 2024, allowing for more global research and scientific collaboration.
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 gym, two bathrooms and a 360-degree bay window offering spectacular views of Earth.
Its entire structure is made up of various working and sleeping modules, and extends the length of a football field (about 100m), making it four times bigger than the Russian space station Mir and about five times as large as the US Skylab.
The ageing structure requires regular maintenance, which is done by astronauts who don spacesuits and venture outside the lab.
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Julie Robinson, an ISS scientist at NASA, insisted that the space station, which has a mass of 420,000kg but is near-weightless in space, is worth the trouble and expense.
The ISS, which is maintained by a rotating crew of six astronauts and cosmonauts who have hailed from 14 countries, allows scientists to study the long-term effects of weightlessness on the human body, she said, while testing new space technologies that will be essential for missions to Mars.
Robinson added that "many of our early research results are making their way into drug development, medical technologies, pathways. We also have Earth-remote sensive instruments that provide unique data about the Earth and its climate and there are a number of new instruments going up in the next two years.
"When you put all of that together it's really an extraordinary set of benefits back here on Earth."
Robinson noted that a robotic arm used at the space station can save lives during brain surgery.
She described the possibilities at the ISS as "unlimited," and noted that a growing amount of private money was supporting research at the space station.
"This is an era of space research that is unlike the past and we are looking at the decades ahead as the time when science can finally pursue these boundaries, explore these frontiers and make these unique discoveries," she said.
"I think as we look back, 20 or 30 years from now, we will call this the era of the space station... because of the number of advances and benefits that will come out."
