Officials say a Russian "Progress" cargo ship has failed to successfully dock with the International Space Station during tests designed to ensure the effectiveness of future docking attempts.
A Russian Mission Control Center spokesman told the Interfax news agency on July 24 that the reasons behind the failure are being investigated.
He said that at a distance of 15 kilometers from the space station, the control system warned of a possible emergency and called off the docking.
Russian Mission Control says the ship is under full control and there is no danger of a collision with the space station.
The U.S. space agency NASA said in a statement that the next docking attempt could occur on July 28 or July 29.
The cargo ship undocked from the station on July 22 in order to perform the tests.
Based on reporting by Interfax, Reuters, and AP