Russian space authorities on Thursday lost contact for hours with a Soyuz capsule carrying three astronauts to the International Space Station, dpa reported.
Ground control also could not pinpoint the exact location of the ISS and had to ask US colleagues at NASA for help, a spokesman told Interfax news agency in Moscow.
A sensitive fiber optic system was likely to blame for the communications problems.
The Soyuz spacecraft blasted off from Kazakhstan early Thursday carrying US astronaut Catherine "Cady" Coleman, Russian cosmonaut Dmitry Kondratyev and Italian astronaut Paolo Nespoli to the station for a five-month stay in space.
They will join fellow expedition members Scott Kelly of the US and Alexander Kaleri and Oleg Skripochka of Russia, who have been living on the ISS since October.