The recent visit of NASA Administrator Charles Bolden to China has generated a high level of attention and controversy. Relations between the USA and China are not exactly cordial at the moment, for a variety of reasons. The problems are so acute that high-placed voices in the USA have questioned if Bolden should even visit China at all, let alone try to forge any links.

Let's put aside a deep analysis of the problems and the animosity, and focus on one issue that seems to be getting lost in the heat. The Chinese space program, notorious for its secrecy and inaccessibility, is making efforts to open up a bit more.

It is not for this author to say exactly how America should respond to any potential Chinese overtures, except to observe that the full implications of any deal need to be examined very carefully before anything is decided or done. But we can expect China to expand its international co-operation on a variety of fronts, and with a variety of nations, in the years ahead.

China has engaged in cooperative activities with Europe and Russia, as well as other nations. The work with Europe has been especially productive, as scientific data and some instruments have been shared.

The upcoming Yinghuo Mars orbiter, China's first mission beyond the Moon, will be launched piggyback with a Russian mission. Yinghuo also carries European instruments and will be partially tracked by European ground stations.

The upcoming Shenzhou 8 mission, which will perform an unmanned docking with the Tiangong 1 space laboratory, will also carry European science experiments. Other successful cooperative ventures include an ongoing Earth observation program with Brazil and the supply of communications satellites to states in Africa and South America.

One high-profile area of international co-operation hasn't been generally discussed by China or other spacefaring nations. How soon will it be before foreign astronauts fly on a Chinese spacecraft?

Nobody knows if China has any plans for such a mission in the future. In the short term, it's simply not on the cards. China's Shenzhou program, which launched its first astronaut in 2003, is moving ahead at slow pace. Years pass between missions. China will probably not be in a position to offer seats to outsiders until its human spaceflight capabilities are fully developed.

This could be a possibility in roughly ten years. Around 2020, China has plans to launch a fairly large space station, assembled in orbit from separately launched modules.

The space station will receive crews launched aboard Shenzhou spacecraft and will be resupplied by cargo spacecraft similar to the Tiangong space laboratory. Once China has built this large space station and launched a couple of long-term expeditions there, it will be fair to say that China has truly become a master of human spaceflight.

The Soviet Union began its own international astronaut program, called Interkosmos, in the 1970s. By then, the Soviets had made spaceflight fairly routine with its Soyuz spacecraft and Salyut space stations. Cosmonauts were trained from Warsaw Pact allies, other Communist states, and nations with geopolitical or economic ties to the Soviet Union.

The major goal of the Interkosmos program was political, with the mystique of spaceflight used to strengthen ties between the Soviet Union and other nations. Some of the Interkosmos missions were really one-hit wonders.

Nations with little advanced technology or aerospace industry suddenly had men in space, but there was no substantial space activity with the Soviet Union (or even within their own borders) once the trophy missions ended.

America did not launch a foreign astronaut until a West German flew on the Space Shuttle in the 1980s. The first pool of guest astronauts for the Shuttle program were drawn from Western Europe, Canada, Japan, Mexico and Saudi Arabia - mostly nations connected with the American-led space station program, or holding strategic or geographical links to the USA.

Will China embark on its own Interkosmos equivalent in the future? Probably not. Even if foreign astronauts fly on Shenzhou missions, the dynamics of the flights will probably be more complex and substantial than handshakes in space.

China's first steps beyond flying citizens of mainland China will be cautious. The first astronaut from beyond the PRC will probably be from Hong Kong. It's been interesting to watch flown Chinese astronauts shunted on goodwill tours of the Hong Kong Special Administrative Region after their return to Earth. One such tour was apparently designed to boost Beijing's standing before a Legislative Council election in Hong Kong.

Spaceflight is already being used to draw Hong Kong and Beijing closer together, and it will probably continue to be used this way. Hong Kong also boasts extensive scientific and technological foundations, making a flight by a Hong Kong astronaut potentially useful for technical reasons.

Once Hong Kong has an astronaut, Macau will not be far behind. The political dynamics are similar.

Areas of China with separatist movements (such as Tibet) could also find themselves tipped to contribute astronauts for political reasons. But it is unclear if such missions would help to produce social stability in these areas, or if such missions could even be counter-productive with some groups.

Taiwan is a tricky case. The island is classified by Beijing as territory of the PRC, despite opinions to the contrary voiced on the other side of the strait. The ambiguity of Taiwan's sovereignty could be disturbed by involving a Taiwanese astronaut in the Shenzhou program.

What flag would he or she wear, and how would the astronaut's nationality be described? Despite recent improvements in cross-strait relations, the Chinese launch of an astronaut from Taiwan seems unlikely to be considered in the near-term.

Where else could guests for Shenzhou come from? China could start recruiting from nearby nations in Asia, but a more likely source is Europe. Co-operation with Europe is already strongly entrenched, and Europe is also strongly supportive of human spaceflight.

European astronauts have flown on both the US Shuttle and Soyuz spacecraft. Europe is considering the development of its own astronaut capsule, but it's not clear how long we will have to wait to see it fly. In the meantime, launching European astronauts aboard Shenzhou could be very attractive.

China could consider crew exchanges with the USA if the two nations ever forge a substantial partnership. This could involve launching Chinese astronauts aboard US spacecraft and sending American astronauts on Shenzhou. In the near-term, America seems most unlikely to commit to such a project.

There's one potential partner that's rarely discussed in human spaceflight circles: Pakistan. Strategic links between China and Pakistan are highly developed. Both nations enjoy very good inter-governmental relations. A Pakistani astronaut launched aboard Shenzhou seems quite feasible, if China wishes to offer a place.

At the moment, Pakistan has no human spaceflight program, and has never launched an astronaut with any other nation. It is also confronted by the rise of a human spaceflight program in India, Pakistan's main strategic and geopolitical rival.

There would seem to be strong motivations for both China and Pakistan to launch a joint mission, if only for political reasons. But we can expect that there would also be scientific and technological aspects to the mission.

In the long-term, China may simply open up access to its spacecraft to the wider world, assuming that they were prepared to pay for the cost of a mission. It's difficult to make any long-term forecasts, given the tricky geopolitical issues that underpin spaceflight.

Even the short-term future is difficult to predict. But China will need to consider whom it will welcome aboard its spacecraft and space stations. Without this sort of planning, China will experience difficulties in forging stronger international partnerships in space.

++ Dr Morris Jones is an Australian space analyst, writer and lecturer. Email morrisjonesNOSPAMhotmal.com. Replace NOSPAM with @ to send email. ++