Chinese spacecraft may soon be allowed to dock with the International Space Station in what would signal an about-turn for Nasa.

The agency has previously been unable to work with China’s space agency owing to US policy, preventing them from becoming a partner on the ISS.

But it has been revealed that both Russia and the US are in discussion with the rising space power, and could allow its spacecraft to bring Chinese astronauts (taikonauts) to live on the station.

Former Russian cosmonaut Alexei Leonov said talks are underway that will allow Chinese astronauts to dock with the ISS, despite US policy forbidding Nasa from working with them. Pictured from left to right are Chinese taikonauts Jing Haipeng, Liu Wang and Liu Yang ahead of a launch in June 2012

China has been a noticeable absentee from the ISS project to date, namely because American legislation prevents Nasa co-operating with them.

According to the policy drawn up by the US Congress in 2011, Nasa is not allowed to work ‘in any way with China'.

This has drawn criticism from many experts, such as UK Astronomer Royal Sir Martin Rees, who called it a ‘deplorable "own goal" by the US.’

THE INTERNATIONAL SPACE STATION The ISS programme is a joint project between Nasa, Roscosmos, Jaxa, Esa and the CSA (Canadian Space Agency). Construction of the ISS began on 20 Novemer 1998 and, since November 2000, it has been continuously manned. At first it supported only a crew of three but now six people can live aboard the station. The station orbits at a height of about 255 miles (410km). It has a total mass of about 990,000 pounds (450,000kg) and has living space roughly equivalent to a five-bedroom house. It completes an orbit of Earth every 92.91 minutes and moves at 17,100 miles (27,600km) per hour. It has now been in space for more than 5,900 days, during which time it has completed more than 92,000 orbits of Earth, and has been continuously occupied for more than 13 years. Advertisement

But in a recent event organised by the Starmus Festival at the Science Museum in London, attended by the MailOnline, former cosmonaut Alexei Leonov suggested that there are groundbreaking talks already taking place.

‘Last year a request was received by the International Association of Space Activities Participants (IASP) from the Chinese to authorise a visit for the Chinese to the ISS,’ he said.

‘The Russian side has agreed to it, and now it is being discussed by the Americans.

‘We have to observe parity, so if the Americans and the European Union agree, we will give the green light for the Chinese spaceships to dock at the station as well.’

Nasa has so far declined to comment on the claims when contacted by MailOnline.

It is not clear in what capacity China would be involved, though, and whether they would be given a seat on a Russian Soyuz spacecraft or invited to bring their own manned spacecraft - Shenzhou - to the ISS.

If the former is the case, it's possible that one or more taikonauts could live and work on board the station alongside Russian, American, European or Japanese counterparts.

But if Shenzhou is allowed to visit, alongside an existing crew of six on the station, then the Chinese visits will likely be more short-lived.

The ISS can only support a crew of six for a prolonged period of time, so if a Shenzhou spacecraft is brought to the station it would likely stay only for a few weeks, rather than months, like the Space Shuttle did when it was still operational.

China has been a noticeable absentee from the ISS project (pictured) to date, namely because American legislation prevents Nasa co-operating with them. According to a policy drawn up by the US Congress in 2011, Nasa is not allowed to work ‘in any way with China'

'The Russian side has agreed to [China docking with the ISS], and now it is being discussed by the Americans,' said Mr Leonov (left) at a recent event at the Science Museum. He has been at the forefront of breaking political tensions in space before, on the Apollo-Soyuz Test Project in 1975 (pictured right)

China has made great strides with its space agency in the last two decades, leading many experts to call for them to be included in future international missions. Shown is the last manned Chinese launch, Shenzhou-10 on 11 June 2013. Their next manned launch is expected in 2016

RUSSIAN SPACE ARTEFACTS TO GO ON SHOW Mr Leonov was speaking at the Science Museum at the unveiling of a new exhibition called Cosmonauts: Birth of the Space Age, which opens on 18 September 2015. This will feature the most significant collection of Russian spacecraft and artefacts ever to be shown in the UK, including several spacecraft from the Space Race in the 1960s and 1970s. It tells the remarkable story of Soviet scientific and technological ingenuity that kick-started the space age. In 1957 the Soviet Union launched Sputnik, the world's first artificial satellite, and four years later sent the first human into space, Yuri Gagarin. Mr Leonov later became the first person to venture out of a spacecraft on a spacewalk on 18 March 1965. It was also revealed that the third Starmus Festival will take place next year in the Canary Islands - a chance for the public to see talks from notable space celebrities. The event in 2016 will be a tribute to Stephen Hawking, who will be in attendance, along with Brian May, a host of Nobel prize winners, scientists and astronauts. Advertisement

Mr Leonov himself is no stranger to long-standing political differences being settled by spaceflight.

After becoming the first human to walk in space on 18 March 1965, he later flew on the Apollo-Soyuz Test Project in July 1975.

This mission saw a Russian Soyuz spacecraft dock with a US Apollo spacecraft, the first time the two nations had ever cooperated in spaceflight, marking the end of the Space Race.

Russia and the US now enjoy an amicable - if not perfect - space-based relationship.

For example, Nasa continues to pay for rides on the Soyuz spacecraft, following the retirement of the Space Shuttle.

But that agreement was thrown into doubt last year after a series of sanctions imposed by Nasa on Roscosmos following political tensions between the countries.

‘After analysing the sanctions against our space industry, I suggest to the USA to bring their astronauts to the International Space Station using a trampoline,’ Dmitry Rogozin, Russia’s deputy prime minister, was quoted as saying.

For now, the situation between Nasa and Roscosmos seems to be under control again.

But China has long been shunned from being involved, and recently they have started pushing for greater cooperation in space.

In an interview with CNN revealed today, taikonaut Nie Haisheng said: ‘As an astronaut, I have a strong desire to fly with astronauts from other countries. I also look forward to going to the International Space Station.

‘Space is a family affair, many countries are developing their space programs and China, as a big country, should make our own contributions in this field.’

This image shows Chinese astronaut Zhai Zhigang stepping outside the orbit module of the Shenzhou-7 spacecraft for a spacewalk on 27 September 2008. If China is allowed to dock with the ISS it is likely that a Shenzhou spacecraft would take them there

The ISS programme is a joint project between Nasa, Roscosmos, Jaxa, Esa and the CSA (Canadian Space Agency), logos shown. Construction of the ISS began on 20 Novemer 1998 and, since November 2000, it has been continuously manned

China has been pushing for more cooperation in space and in an interview with CNN revealed today, taikonaut Nie Haisheng (pictured) said: ‘As an astronaut, I have a strong desire to fly with astronauts from other countries. I also look forward to going to the International Space Station'

Nasa Administrator Charles Bolden (pictured) has said previously that future manned space missions - such as to Mars - will be an international endeavour. But whether China will be involved in something like this, or even the current ISS programme, remains to be seen

When the China National Space Administration (CNSA) was first established in 1993, and the country started to push funding towards spaceflight, it approached Nasa for help with its fledgling agency.

But US policy was soon drawn up preventing Nasa from entering into any sort of agreement, forcing the CNSA to go it alone.

But it has been largely successful; in the last decade alone it has sent taikonauts to space on its Shenzhou spacecraft, built an orbiting space laboratory called Tiangong 1 and even landed and operated a rover on the moon - Chang’e 3.