Russia blames rocket failure on mistake during assembly

A Russian space investigation has found asensor that was damaged during assembly forced a Russian rocket to abort its trip two minutes after it was launched, a top Russian official said Thursday.

The Soyuz-FG rocket carrying NASA astronaut Nick Hague and Roscosmos cosmonaut Alexei Ovchinin failed shortly into the Oct. 11 flight, sending their capsule into a sharp fall back to Earth. The two men landed safely on the steppes of Kazakhstan despite the failed launch, the first of its kind for Russia's manned program in over three decades.

A day earlier, SergeiKrikalyov, a seniorRoscosmosofficial, told reportersa malfunction of a sensor that signals the jettisoning one of the rocket's four side boosters caused the booster to collide with the second stage of the rocket.

But he didn't explain why the sensordidn't work.

Oleg Skorobogatov, who led the probe into the accident, told reporters Thursday that the investigation found that the sensor was damaged during the final assembly at the launch pad in Kazakhstan.

"The cause of the abnormal separation was the failure to open the lid of the exhaust nozzle of the oxidizer tank of the 'D'block due to the deformation of the stem of the contact separation sensor committed during assembly of the 'package'at the Baikonur Cosmodrome," he said.

Russian space agency Roscosmos aired footage filmed by an onboard camera, showing the Soyuz blasting off and climbing normally until three of its booster rockets detach, with one of them appearing to fall inwards, rather than away from it.

The Soyuz is then knocked sharply off its trajectory and can be seen shaking and swinging as the footage is partly obscured by a spewing white cloud. Skorobogatov said the Soyuz's central block was hit "in the fuel tank area, causing a depressurization and, as a result, a loss of the space rocket's stabilization."

Russian rockets are manufactured in Russia and then transported by rail to the Russia-leased Baikonur cosmodrome in Kazakhstan.

The last time Russia saw an aborted manned launch was in 1983, when two Soviet cosmonauts jettisoned and landed safely after a launch pad explosion. More recently, Russia's space program has been dogged by a string of failed satellite launches involving unmanned vehicles.

Tests, additional training

Skorobogatov said officials are now taking steps, including putting all assembly staff through competence tests and additional training, to make sure such malfunctions don't happen again.

The rocket producer will also take apart two other rockets that have been recently assembled and are due to launch in the coming weeks and then re-assemble them, as they might have the same defect, Skorobogatov said.

Roscosmos officials on Wednesday met with their counterparts from NASA to give them a full briefing on the malfunction, Roscosmos director general Dmitry Rogozin said Thursday.

Russian space officials plan to conduct two other unmanned Soyuz launches before launching a crew to the space station.

The current space station crew made up of NASA's Serena Aunon-Chancellor, Russian Sergei Prokopyev and German Alexander Gerst was scheduled to return to Earth in December after a six-month mission but will have to stay there for at least an extra week or two to ensure a smooth carry-over before the new crew, including Canadian astronaut David Saint-Jacques, arrives in early December.

The Russian Soyuz spacecraft is currently the only vehicle that can ferry crews to the International Space Station after the U.S. space shuttle fleet retired. Russia stands to lose that monopoly with the arrival of SpaceX's Dragon and Boeing's Starliner crew capsules.