Russian experts will try to make contact with one of its cargo ships orbiting the Earth after it went out of range because of 'faulty' antennae.
Ground control said the sensors on the cargo ship, are not working properly after it was launched from Kazakhstan on Tuesday 28 April.
It is currently transporting about 2.6 tonnes of fuel, water, dry goods and oxygen for 43 astronauts, including a new three-man crew operating the International Space Station.
"The ship is in a zone of visibility, but its sensors are not working. The specialists are trying to find out why," a source from the space program, told Russian news agency Interfax.
It was meant to touchdown at the space station less than six hours after lift-off from the Baikonur Cosmodrome at 10.07am (Moscow time).
"The ship is continuing to fly. According to our information, the solar-powered batteries have opened, so there are no problems with lack of energy," the source said.
It is hoped Progress will instead dock at the station on Thursday 28 April, at around 5.03am Eastern Daylight Time (9.03am GMT). Two-day flight patterns are normally used on previous Russian resupply missions.