Russia said an unmanned supply ship set for the International Space Station will fall back to Earth Friday and burn up in the atmosphere, after the spacecraft suffered a communications failure.

The Progress supply ship is expected to "end its existence on May 8," between 1:23 a.m. and 9.55 p.m, Moscow time (2223 GMT Thursday and 0655 GMT Friday)," the Russian space agency said in a statement released Wednesday.

"The space ship will completely burn up in the layers of the atmosphere and only a few small parts of elements of its construction could reach the surface of our planet," the space agency said.

It said the crash would be similar to a planned descent. Russia sends three or four such spacecrafts per year to supply the ISS. They then fall back to Earth and burn up in the atmosphere above the Pacific Ocean.

The spacecraft, a Soviet design generally known for its reliability, blasted off for the ISS on April 28 carrying cargo including oxygen, water and spare parts for the orbiting space laboratory with a crew of six international astronauts, one of whom is set for a full year stint.

A few hours after launch, mission control lost contact with it.

A special commission is looking into the incident, the deputy head of Roscosmos space agency Alexander Ivanov said last week.

The ISS crew are not in danger as an American supply ship could bring cargo by June 19.

But a source in the space industry told Interfax news agency on Tuesday that mission control has told the crew to conserve resources.

Russia has recently suffered a series of glitches exposing shortcomings in its space programme.

An earlier Progress supply ship crashed into Siberia shortly after launch in 2011. Moscow has also lost several lucrative commercial satellites.

Since the mothballing of the US shuttle, Moscow has had a monopoly on sending astronauts to the ISS from its Baikonur cosmodrome in Kazakhstan.