A glitch caused the International Space Station to change orbit on June 9, but the crew was not in danger, the Russian space agency said.
Roskosmos said the engines of a Soyuz spacecraft docked at the station unexpectedly started during testing of the radio system that controls the docking procedure, knocking the station off course.
Steps were taken to stabilize the station and specialists are now working to determine what caused the engines to start, the agency said.
Two Soyuz spacecraft are docked at the station, and one of them is scheduled to return three of the six crew members to Earth this week.
Roskosmos said the landing would go ahead as planned June 11.
The glitch follows the recent failure of a Soyuz booster rocket, which is used to launch manned Soyuz spacecraft and send Progress cargo ships to the space station.