TWO astronauts survived a dramatic emergency landing after boosters on their rocket spectacularly failed as they headed towards the International Space Station.

The Russian Soyuz rocket carrying American Nick Hague and Russian Aleksey Ovchinin suffered a booster malfunction during launch in Kazakhstan. But the mission had to be aborted soon after launching at an altitude of about 50km after only 123 seconds.

Russian investigators said they were launching a criminal probe into the incident, the first accident on such a manned flight in the country’s post-Soviet history.

Moscow has also grounded its manned rocket program, which has been the only way for astronauts and cosmonauts to travel to and from the ISS since 2011.

The Russian space industry has suffered a series of problems in recent years, including the loss of a number of satellites and other spacecraft.

Footage from inside the Soyuz apparently showed the two men being shaken violently as the malfunction happened. A large plume of smoke could be seen coming from the rocket at the moment the boosters failed.

Space officials from both Russia and the US said the two astronauts endured higher than normal G force.

NASA said there was an “issue with the booster” and the crew was “returning to Earth in a ballistic descent mode” in a rescue capsule.

The agency later confirmed the crew had landed safely back on earth at 8.23pm (AEST) in Kazakhstan. They were flown to Moscow where a major investigation into the near tragedy has begun.

Reports from Russia early today indicated a criminal inquiry was one of the avenues authorities were looking at.

International Space Station commander Alexander Gerst said he was grateful the astronauts were well after the rare launch abort ended their journey.

Mr Gerst, a European Space Agency astronaut from Germany, tweeted from orbit after the failed launch: “Spaceflight is hard. And we must keep trying for the benefit of humankind.”

Russia has promised to share all relevant information with the US.

Witnesses said the launch had gone smoothly which suggested the problem happened at a very high altitude.

Vladimir Putin’s spokesman Dmitry Peskov told reporters in Moscow: “Thank God the crew is alive.”

The timing of the incident - just before the Soyuz entered orbit - meant its crew were able to activate emergency protocols and send the rocket back to earth.

Oleg Orlov, the head of the Institute for Medical and Biological Problems, Russia’s top space medicine research center, said on Russian television the astronauts endured six Gs during the sharp ballistic descent.

While that was higher than normal they were trained to endure such loads, he added.

NASA Administrator Jim Bridenstine said in a statement that Hague and Ovchinin were in good condition and will be transported to the Gagarin Cosmonaut Training Center in Star City outside Moscow.

He added that a “thorough investigation into the cause of the incident will be conducted.”

A senior Cabinet official said Russia was suspending manned space launches pending a probe into the booster rocket failure.

The Russian space program has been plagued by a series of launch failures and other incidents in recent years, but Thursday’s incident was the program’s first manned launch failure since September 1983, when a Soyuz exploded on the launch pad, Associated Press reported.

They landed about 20km east of the city of Dzhezkazgan in Kazakhstan. Spacecraft returning from the ISS normally land in that region.

Earlier NASA warned the Soyuz capsule was returning to Earth “via a ballistic descent, which is a sharper angle of landing compared to normal”.

It said there was an issue with “the booster from today’s launch”.

Russian Roscosmos space agency and NASA said the three-stage Soyuz booster suffered an emergency shutdown of its second stage.

The rocket is carrying a Russian cosmonaut and an American astronaut who had set off for a six-month mission at the International Space Station, on a relatively rare two-man launch.

NASA rookie Nick Hague and Roscosmo second-time flyer Aleksey Ovchinin blasted off for the orbital lab from the Baikonur cosmodrome in Kazakhstan as scheduled at 7.40pm (AEST).

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

“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.