BAIKONUR, Kazakhstan: The ongoing global economic turmoil and increasingly strained ties between Moscow and Washington will not stand in the way of further space exploration, Russia’s space agency chief said Saturday.

Roscosmos director Anatoly Perminov spoke on the eve of the launch of the international space station’s next crew aboard a Russian Soyuz rocket from the Russian-leased Baikonur cosmodrome in Kazakhstan.

Soyuz rockets will be the only way for astronauts and cosmonauts to get to the space station after the US space shuttle fleet is retired in 2010 - a fact that has greatly worried US lawmakers. Some US officials are wary about relying solely on the Russian programme, given Moscow’s increasingly assertive foreign policies.

But Perminov said recent US congressional decisions on future collaboration and the presence of US astronauts at Baikonur showed that Washington has no desire to politicise the issue. Congress earlier this month gave U.S. space agency NASA permission to purchase seats on the Soyuz after 2010.

“Cooperation is first and foremost international and it cannot be said that space has any boundaries,’’ Perminov said. He also said the current financial crisis battering Russia and global financial markets will not halt the Russian space program.

Further concerns about the reliability of the Soyuz arose in April when the capsule descending to Earth failed to separate on time, sending the crew into a “ballistic’’ descent. It was the third time a Soyuz descent had been marred by problems. Perminov pledged the incident wouldn’t be repeated.

“I have received a written statement from Nasa telling me they are satisfied with our work, and as result the mission will go ahead,’’ he said.

Nasa two years ago awarded Lockheed Martin the contract to build the Orion spacecraft to replace the space shuttles. The craft is expected to make its maiden flight by 2014. Two Americans - software millionaire Richard Garriott and astronaut Michael Fincke - and Russian cosmonaut Yuri Lonchakov are to blast off Sunday for the space station.

The three travellers, joined by a backup crew, appeared relaxed at a pre-launch news conference held behind a glass screen to protect against any infections. Fincke downplayed any suggestions that political tension would have any bearing on the mission.

“We know there are politics on the ground, but that does not affect our crew and it does not affect our space mission,’’ Fincke said. “We are a symbol of what people can achieve by working together.’’

Garriott, the son of a former US astronaut, reportedly paid US$30 million to travel to the space station for 10 days. He said the space programme has historically succeeded in overcoming diplomatic differences.

“Thirty years ago, during my father’s time at Nasa, Russian cosmonauts, scientists and engineers always got on wonderfully with their US partners,’’ he said. Garriott, who made his fortune designing computer games, plans to carry out experiments, including one involving protein crystal growth. He also plans to take photographs to record how the Earth’s surface has changed in the 35 years since his father Owen’s voyage.

Fincke said the main goal of his mission will be to expand the capacity of the station to host up to six astronauts, from three currently, with additional sleep spaces, a toilet and more oxygen generation. Garriott is to return to Earth later this month with Russian cosmonaut Yuri Volkov, who has been at the station since April.

Volkov was the first man to follow his father, a decorated cosmonaut from the Soviet era, into space.