Pavel Vinogradov said that he and the two other crew of the Soyuz capsule which touched down in Kazakhstan Wednesday had groped their way through the landing after they lost all data about their height from the ground.
"There were problems. For some reason after the undocking all our parameters disappeared. Essentially, after the undocking, we flew blind," he said at the Star City cosmonaut training centre outside Moscow, quoted by Russian news agencies.
He said the rescue teams were able to radio to the crew that they were 300 metres (1,000 feet) and then 100 metres (330 feet) from the ground in the Soyuz capsule, which lands vertically with the help of a parachute after reentering the atmosphere.
"I managed to count eight seconds and we touched down very softly," he said, adding that aside from the usual G-forces and jolting "everyone felt normal".
Russia is currently the only nation capable of transporting humans to the ISS in its Soyuz rocket and capsule system after the withdrawal of the US shuttle.