China's Tiangong space station is expected to welcome its first foreign visitor — a Pakistani astronaut who will likely become the first from the nation to fly in outer space, according to a heavyweight cooperation agreement.

The agreement, signed by the China Manned Space Agency and Pakistan's Space and Upper Atmosphere Research Commission at a ceremony in Islamabad on Friday, covers the bilateral efforts to select and train Pakistani astronauts and then send some of them to China's Tiangong space station, which has been in orbit for nearly four years.

Its signing, witnessed by Pakistani Prime Minister Shehbaz Sharif, marks the first time for China to help a foreign nation select and train astronauts, and also the first time for Tiangong to expect a non-Chinese visitor, the agency said in a news release.

It said the two sides will spend about one year to complete the selection process and then send the Pakistani candidates to China to receive comprehensive and systematic training. It did not mention whether the selection has begun or when it will start.

After the Pakistani trainees are ready, one of them will be chosen as the first foreign crew member to fly with Chinese astronauts toward Tiangong space station and spend a short-term stay inside the colossal spacecraft, currently orbiting Earth at about 400 kilometers above the ground, the agency noted.

Until now, the highest altitude any Pakistani citizen has ever achieved is about 87.4 km, which was reached by female polar adventurer and artist Namira Salim during a 55-minute suborbital journey arranged by British-American aerospace company Virgin Galactic on Oct 6, 2023.

It is commonly recognized that the Karman line, at an altitude of 100 km above sea level, is the start of outer space and the threshold for orbital flight.

The signing of the cooperation agreement has created fresh opportunities and set a model for more developing countries to engage in international manned space collaboration. It is expected to inspire nations worldwide to join hands in exploring the mysteries of the universe and collectively forging a new chapter in advancing shared interests for the benefit of all humanity, according to the release.

Since the launch of Tiangong's first component in April 2021, Chinese space officials have floated the idea of selecting and sending foreigners to the space station.

Key project leaders such as Yang Liwei, the first Chinese astronaut in space and now a deputy chief planner of the country's manned spaceflights — and Lin Xiqiang, deputy head of the China Manned Space Agency — have said several times that China is open to international cooperation on its space station.

Chen Shanguang, another senior official in the country's manned space program, said in February 2023 that "multiple countries have told China that they hope to send their astronauts to Tiangong".

Pang Zhihao, an expert on space exploration technology and a renowned writer on spaceflight, said that the Pakistani trainees will need to undergo a series of stringent training and tests before qualifying themselves for actual spaceflight.

"Of course, the first and foremost lesson they need to take is the Chinese language. The language to be spoken inside a Chinese station is naturally Chinese. Second, though they must have had good physical and psychological qualities, they still need to train very hard to make their body and mind perfectly prepared for a space mission. This is especially important if some of the Pakistani trainees were not selected from among pilots. They must learn how to eat, drink, sleep and deal with personal hygiene in microgravity, which poses a huge challenge to anyone flying into space," Pang said.

After arriving at the space station, the selected Pakistani astronaut will likely carry out at least one scientific experiment designed by Pakistani researchers, according to the expert.

Another Chinese spaceflight expert who wished to remain anonymous said that the new agreement is a very good example for space cooperation between developing countries and for South-South cooperation.

"It will effectively boost Pakistan's social development and help it become an emerging force in the international space arena," he said.