NASA plans to allow tourists to visit the International Space Station from 2020 – at an estimated cost of more than $50million (£39million) per trip.

Until now, the floating space lab has only been accessible to astronauts representing state-level space agencies.

7 Astronauts have been living on the ISS since 2000 – but it'll soon accept private tourists too Credit: Mediadrumimages/GiuseppeDeChiara/MichaelGorn/NASA

In a surprise announcement today, Nasa confirmed that it would be "opening the International Space Station for commercial business".

It means that private companies will be able to take "private astronauts" to the ISS for up to 30 days.

"The agency can accommodate up to two short-duration private astronaut missions per year to the International Space Station," Nasa explained.

"These missions will be privately funded, dedicated commercial spaceflights."

Private visitors were banned from the space station - which has cost US taxpayers £785million since it was launched in the 1990s - but Nasa needs cash to help fund its dream of putting a man and woman on the Moon by 2024.

7 The ISS comes equipped with five bedrooms, two bathrooms and a gym – plus plenty of science labs Credit: NASA

7 How the cost of staying on the International Space Station could cost £27,500 a night

Transport will be provided by both Boeing and Elon Musk's SpaceX, who are currently developing capsules that can carry humans to the ISS.

It's expected that a trip will likely cost around $50million (£39million) per astronaut, according to early estimates – but could easily rise well above that figure.

The spaceflight to the ISS will account for a large chunk of the cost. But chief financial officer Jeff DeWit joked: “It won’t come with any Hilton or Marriott points.”

Nasa typically pays around $75million for seats aboard a Soyuz spacecraft destined for the ISS, and even paid $82million per seat in 2015.

However, Nasa says seats aboard the SpaceX Crew Dragon and/or Boeing CST-100 capsules will cost roughly $58million per seat.

It's these capsules that will be used to ferry astronauts up to the ISS – but the cost continues to rise after the journey.

Keeping astronauts on board the ISS is a pricey business.

For instance, the regenerative life support and toilet costs $11,250 (£8,800) per astronaut each day.

And general supplies – like food and air – cost $22,500 (£17,500) per astronaut each day.

Nasa will get around $35,000 (£27,000) per night that a private astronaut spends on board the ISS.

A large bank balance won't be enough either: you'll have to pass Nasa's rigorous health checks and training procedures.

7 The cost of space travel is exorbitant – so only Earth's wealthiest would-be cosmonauts need apply Credit: Nasa

What is the ISS? Here's what you need to know about the International Space Station... The International Space Station, often abbreviated to ISS, is a large space craft that orbits Earth and houses astronauts who go up there to complete scientific missions

Many countries worked together to build it and they work together to use it

It is made up of many pieces, which astronauts had to send up individually on rockets and put together from 1998 to 2000

Ever since the year 2000, people have lived on the ISS

Nasa uses the ISS to learn about living and working in space

It is approximately 250 miles above Earth and orbits around the planet just like a satellite

Living inside the ISS is said to be like living inside a big house with five bedrooms, two bathrooms, a gym, lots of science labs and a big bay window for viewing Earth

As part of its "commercialisation" of the ISS, Nasa will be making one space station port and utilities available for a private company to "attach a commercial module to".

And it hopes that in the long-term, there will be lots of private space stations floating just above Earth.

"In the long-term, NASA’s goal is to become one of many customers purchasing services from independent, commercial and free-flying habitable destinations in low-Earth orbit," Nasa explained.

"A robust low-Earth orbit economy will need multiple commercial destinations, and NASA is partnering with industry to pursue dual paths to that objective that either go through the space station or directly to a free-flying destination."

Whatever ends up going into space, it's unlikely to get cheaper any time soon.

Even SpaceX charges $62million (£48.7million) to send commercial satellites into orbit with its relatively new Falcon 9 rocket.

And Axiom Space, a Houston-based company hoping to organise trips to the ISS, has pledged to charge $55million (£43.2million) for a 10-day trip to the ISS.

Bill Gerstenmaier, Nasa’s head of human exploration, told a news conference: “We have no idea what kinds of creativity and literally out-of-the-world ideas can come from private industry.”

But super-rich tourists and filmmakers are also being invited to make use of the experience.

And in a message recorded on the ISS, astronaut Christina Koch said it would make space “more accessible to all Americans”.

Jeff Manbar, the CEO of ISS logistics company Nanoracks, said: “It’s a very important step forward. This is the beginning of a new chapter.”

7 How we imagine they might advertise the trip

7

What does the latest SpaceX Crew Dragon mission mean for the future of human space travel?

So why is Nasa letting tourists travel to the ISS?

The main advantage seems to be keeping costs down, as the ISS is very expensive to run.

But it's also about continuing to test space travel – to make it safer and cheaper for everyone.

"Market studies identified private astronaut missions to low-Earth orbit as a key element to demonstrate demand and reduce risk for future commercial destinations in low-Earth orbit," Nasa explained.

The long-term plan is to create space stations near Earth that can be used as stop-off points for deeper trips into space.

Nasa hopes to set up several "lunar gateways" starting from 2028 that will float near the Moon, and could be used for crewed missions to Mars.

"The first Gateway is about the moon, but I think the second Gateway, being a deep-space transport, again using commercial and international partners, enables us to get to Mars," said Nasa top boss Jim Bridenstine, speaking last year.

"What we don’t want to do is go to the surface of the moon, prove that we can do it again, and then be done. We want to go to stay.

"And the Gateway, in my view – I’ve been convinced – enables us to take advantage of commercial and international partners in a more robust way so we are there to stay, it enables us to get to more parts of the moon than ever before, and it enables us to get to Mars."

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A stunning Nasa timelapse recently revealed an astronaut's view as the ISS soars over Earth. In 2018, Nasa astronauts played the first game of tennis in space during a televised match on the ISS.

Also last year, ISS astronauts enjoyed a festive treat – after Elon Musk shipped Christmas dinner to them.

Would you like to visit the ISS? Let us know in the comments!

7 Nasa will charge £27,500 for each night aboard the station Credit: NASA / eyevine

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