Two astronauts make emergency landing after booster rocket carrying them to the International Space Station fails

Russian cosmonaut Alexey Ovchinin (left) and US astronaut Nick Hague (right) saw their flight aborted. Credit: AP

Two astronauts from the US and Russia are safe after making an emergency landing when a booster rocket carrying them to the International Space Station failed.

Nasa astronaut Nick Hague and Roscosmos's Alexei Ovchinin lifted off as scheduled at 2.40pm local time from the Baikonur cosmodrome in Kazakhstan on a Soyuz booster rocket.

They were to dock at the orbiting outpost six hours later - but the booster suffered a failure minutes after the launch.

Both space agencies have confirmed the astronauts are in good health after their emergency landing.

  • Video shows moment of malfunction

Rescue teams have reached the pair and they have been taken out of the capsule, according to Nasa.

The capsule landed about 20 kilometers (12 miles) east of the city of Dzhezkazgan in Kazakhstan.

  • Two astronauts picked up in Kazakhstan

During the landing, Hague and Ovchinin endured 6.7 times the force of gravity.

It is not yet clear whether the crew already on board the International Space Station - an American, German and Russian - will now have to extend their six-month mission.

Alexander Gerst, one of those on board the ISS, praised the rocket's safety mechanisms, describing spaceflight as "hard".

And UK astronaut Tim Peake echoed his words, saying that Soyuz had "proved their worth".

The launch failure marks an unprecedented failure for the Russian space programme, which has been dogged by a string of launch failures and other incidents in recent years.

"Thank God, the crew is alive," Russian President Vladimir Putin's spokesman, Dmitry Peskov, told reporters when it became clear that the crew had landed safely.

Relations between Moscow and Washington have sunk to post-Cold War lows over the crisis in Ukraine, the war in Syria and allegations of Russian meddling in the 2016 US presidential vote, but the two countries have maintained cooperation in space.

  • Future of ISS 'at risk'

Tom Clarke says the Soyuz issue causes a problem for the ISS.

Any potential issue with the Soyuz rockets could mean the future of the ISS is at risk, according to ITV News Science Editor Tom Clarke.

The ISS has been constantly manned for 18 years and needs round-the-clock attention, so if the three crew on board must return to earth this could cause a problem, he explained.

"The problem is, how long will it take to get the Soyuz rockets working again - they're the only things that can get the men to and from the ISS," Clarke siad.

"If it's a simple problem they can diagnose it quite quickly... if, however, it's a complex problem, or a manufacturing fault or something like that, that raises a big question because the Soyuz capsule that's on there can only last for another 200 days or so before it has to come back to earth."

  • How the launch unfolded

The rocket lifted off as scheduled at 2.40pm (8.40am GMT). Credit: PA
Within minutes, the Soyuz booster suffered an unspecified failure. Credit: PA
Search and rescue teams were immediately scrambled to recover the crew. Credit: PA