Space explorers from all countries should be united to reach the common goal, said Valeriy Tokarev, a retired Russian cosmonaut, in an interview with CGTN.

"When we enter space, there are no borders," Tokarev recalled. "There are no rivals like we're used to on Earth. Space is shared, and mastering it starts with international cooperation. Yes, we were representing different countries, but we were united by one common goal and common idea. And that translates onto Earth. And that existence of interpersonal relations increases the level of trust."

Valeriy Tokarev was the second Russian cosmonaut to visit the International Space Station (ISS), travelling there on a NASA Discovery shuttle in 1999 for the first ever docking with the space station.

Six years later, he returned for a longer mission and spent more than six months on board.

In both launches, he was the only Russian crew member, an experience that has given him an international outlook.

Tokarev worked closely with American and Canadian astronauts on both of his missions. That period was the heyday of international cooperation in space.

Russia has been a pioneer in the field of space stations for decades.

Half a century ago, the Soviet Union was the first country to send a space station – Salyut 1 – into orbit back in 1971.

Fifteen years later, the Mir became the first modular space station. A primarily Russian project, it welcomed many international crews in its lifespan of more than 15 years.

As decades went by, such endeavors became more collaborative, culminating in the ISS.

Now, Russia is considering withdrawing from the ISS altogether.

It has plans to build its own modular space station which Roscosmos chief Dmitry Rogozin said would stay in orbit permanently.

He recently told a Russian newspaper, "We want to design open architecture, when one module that has used up its service life can be replaced by another one. This station could eternally stay in orbit, gradually and smoothly replacing its spent elements."

There are still many hurdles for the Russian space agency before such a project can be realized, not least securing sufficient funding.

Tokarev says the high price tag of space endeavor is another reason that countries should work together.

"Every big country has its own ambitions. But mastering the serious challenges of outer space is exceedingly difficult alone. It is difficult in terms of resources, in terms of finances. International cooperation has a positive effect," he said. "But that's not mutually exclusive to having a country's own national project."

As more countries and private companies get involved in the space race, the nature of cosmic collaboration is changing.

Russia wants to forge its own path and remain a pioneer in the field of orbital stations. But the country is unlikely to ever eschew international cooperation altogether.