Soyuz rocket carrying US, Russian astronauts to ISS malfunctions during launch

Booster rockets carrying a Soyuz spacecraft with a Russian and a U.S. astronaut on board headed for the International Space Station failed mid-air on Thursday, forcing the crew to make an emergency landing, Russian news agencies reported.

NASA said the spacecraft was making a "ballistic descent" - meaning under the force of gravity alone - toward Earth and that search and rescue teams were heading towards the expected touchdown site.

"The emergency rescue system worked, the vessel was able to land in Kazakhstan... the crew are alive," Roscosmos said in a tweet.

NASA rookie astronaut Nick Hague and second-time flyer Aleksey Ovchinin of the Russian space agency landed without injuries, the Interfax news agency reported.

"The launch had a problem with the booster (rocket) a few seconds after the first stage separation and we can confirm now that the crew has started to go into ballistic descent mode," the voice-over on a NASA livestream from mission control in Houston said.

A tweet from the American space agency's account read: "Search and rescue teams are in the air and heading towards the expected touchdown location for the Soyuz spacecraft returning to Earth carrying two crew members."

The Kremlin confirmed the men had survived. Russian presidential spokesman Dmitry Peskov told journalists: "Thank God the cosmonauts are alive".

The duo had lifted off from the Russian-operated Baikonur Cosmodrome in Kazakhstan.

They were set to join the crew of Alexander Gerst, the station's first-ever German commander, as well as U.S. astronaut Serena Aunon-Chancellor and Russian cosmonaut Sergei Prokopyev. That trio arrived in June.