MOSCOW, June 9. /TASS/. The engines of a Soyuz spacecraft, docked to the International Space Station (ISS), which is to return on June 11 three astronauts to Earth, started abnormally and the location of the station changed, Russian Federal Space Agency Roscosmos said Tuesday.
"Today, on June 9, 2015, at 18:32 Moscow Time, during scheduled testing of the radio system of rapprochement and docking of the International Space Station and the Soyuz spacecraft, Soyuz’s engines started abnormally, which led to a slight change of the ISS location," Roscosmos said.
"All required measures to stabilize the ISS have been taken," it said.
Roscosmos said "there is no threat to the ISS crew, the station itself and a normal return of the Soyuz TMA-15M to Earth."
"Roscosmos specialists are establishing the causes of what happened, and the results will be reported later," it said.
The space agency did not specify the engines of which of the two Soyuzes docked to the ISS started abnormally.
A crew of six - Russian cosmonaut Anton Shkaplerov, NASA astronaut Terry Virts and European Space Agency astronaut Samantha Cristoforetti (flew to the ISS on board the Soyuz TMA-15M), as well as Russian cosmonauts Gennady Padalka, Mikhail Korniyenko and NASA astronaut Scott Kelly (arrived at the station on board the Soyuz TMA-16M) currently work on board the ISS.
A descent capsule of the Soyuz TMA-15M spacecraft with three astronauts is expected to land in Kazakh steppe on June 11. The astronauts were to have returned May 14 but had to stay in orbit longer due to April’s accident involving the Progress M-27M spacecraft.
The next manned spacecraft - Soyuz TMA-17M - will blast off toward the ISS July 24.
The Progress M-27M cargo spacecraft was launched on April 28 from the Baikonur space center on a Soyuz-2.1a carrier rocket. The rocket took the spacecraft to a higher orbit than required to dock with the ISS. After a few unsuccessful attempts to get control of the spacecraft, experts gave up the idea. The Progress was taking food, oxygen and other cargos to the ISS crew. It burned in dense atmosphere May 8.
Roscosmos concluded that the cause of the accident was "abnormal separation" of the Soyuz third stage and the Progress due to decompression of the rocket’s fuel tanks, caused by an unaccounted design property.