A Soyuz space rocket carrying a NASA astronaut and a Russian cosmonaut suffered an engine problem and the crew had to make an emergency landing minutes after lift-off on Thursday.
Here is what we know so far about the latest setback to the Russian space industry:
Blast-off seemed normal
The lift-off from Russia's cosmodrome in Baikonur, Kazakhstan, took place on a bright sunny day.
The rocket was to carry NASA's Nick Hague and Russia's Aleksey Ovchinin to the International Space Station.
It lifted off on time at 0840 GMT, an AFP photographer at the scene saw.
Live video transmitted by NASA and Roscosmos suggested that all went as planned.
"The rocket lifted off absolutely as normal," said AFP photographer Kirill Kudryavtsev, who was watching at Baikonur and has covered the space launches many times.
"But after the first stage separation, I had a sense that there was something like a flash."
Accident with booster
Live video footage showed the rocket going up as far as visible to the cameras.
NASA and Roscosmos broadcast footage of the two crew members inside the capsule speaking to mission control and working on their tablet computers.
Suddenly after two minutes of flight, three short beeps were heard, indicating an emergency situation.
"An accident with the booster, 2 minutes, 45 seconds," the voice of Ovchinin could be heard saying calmly immediately afterwards.
NASA said there had been a "failure of the booster."
The incident came as the rocket was travelling about 4,700 miles (7,563 kilometres) per hour, 119 seconds into the voyage, NASA said.
Ovchinin, who was the commander of the Soyuz space craft, said they felt that they were already in weightlessness.
The emergency system was activated to allow the capsule containing the astronauts to land back on Earth in ballistic descent mode.
The astronauts said they were experiencing strong G-force. "We're tightening our seatbelts," Ovchinin said.
Russian news agencies initially quoted unnamed space officials as saying that the crew had landed in Kazakhstan and were in communication with mission control.
"They have landed in a ballistic landing," NASA TV reported.
Russian space agency chief Dmitry Rogozin confirmed on Twitter at 0920 GMT that "The crew has landed. All are alive."
Kremlin spokesman Dmitry Peskov told journalists: "Thank God, the cosmonauts are alive."
Roscosmos said on its website almost an hour after blast-off that "the emergency rescue system functioned and the spacecraft made a landing in Kazakhstan along the flight route."
NASA said that the astronauts were in "good condition" after a search and recovery team reached the landing site and helped them leave the capsule.
They were flown by helicopter to the nearest airport in Zhezkazgan. Roscosmos tweeted photographs of them being examined there by medics.
The two were then due to be flown back to Baikonur over 400 kilometres away.
RIA Novosti state news agency reported that the last similar accident took place in the Soviet era in 1983.
During a flight crewed by cosmonauts Vladimir Titov and Gennady Strekalov, a fire broke out in the rocket booster but the cosmonauts landed safely in their capsule and were uninjured.
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