An unmanned Russian spaceship carrying 2.5 tonnes of cargo may be unable to properly dock with the International Space Station after its navigation antenna failed to properly deploy, Interfax said on Thursday.
The news agency report cited a Russian space industry source as saying that the Progress cargo carrier may be impeded in its docking operation by the improperly protruding antenna.
The antenna would create a space between the craft and the space station's hermetic seals that would make opening of the station's hatches too dangerous, the report said.
"After the cargo carrier manually docks with the station, the unopened antenna could run up against the docking node," the unnamed source told Interfax.
"In that case, the docking process will be impossible to complete in a perfectly hermetically-sealed manner."
The source added that this would then require for the crew on board the ISS to perform a spacewalk during which the problem could be fixed.
The Progress is taking up fresh fuel and oxygen supplies as well as equipment and water.
Russia's Roscosmos space agency said it would continue sending radio signals to the Progress trying to fix the problem throughout Thursday afternoon.
The navigation antenna failed to deploy properly shortly after the Progress lifted off on top of a Soyuz rocket from the Baikonur space station that Russia leases from Kazakhstan on Wednesday.
The 14-year-old international space lab is currently manned by two American astronauts and a Canadian as well as three Russian cosmonauts.