An Incredible escape for two astronauts heading for Space Station as rocket fails on the edge of space and they are forced to hurtle back to Earth (video)

Two astronauts made it back to Earth alive today after their rocket malfunctioned as they were travelling at thousands of miles an hour on the edge of space while carrying them to the International Space Station, cockpit audio reveals.

Russian Aleksey Ovchinin and American Nick Hague got back safely to Earth after the booster on their Soyuz rocket malfunctioned at 164,000 feet and the rocket automatically turned back during a dramatic 7G "ballistic re-entry".

Video footage from the launch shows the pair being shaken around as the engine malfunctioned in mid-flight. Ovchinin was as calm as possible as he realised what was happening after they were rocked violently around in their seats by the force of the booster malfunction.

"An accident with the booster, 2 minutes, 45 seconds. That was a quick flight," he said in a calm voice in a streamed video of the incident.

"We're tightening our seatbelts," cosmonaut Ovchinin said in the video.

The two-strong crew landed safely at a site in Kazakhstan hundreds of miles away from the initial launch site.

Russia says it has opened a criminal investigation and grounded all Soyuz flights. The accident comes weeks after a hole was discovered in the International Space Station amid talk from the Russian space authorities of deliberate sabotage.