MOSCOW, Aug. 5 (Xinhua) -- A Russian supply ship docked with the International Space Station (ISS) on Sunday after a three-day orbit flight, the mission control outside Moscow said.

"Progress M-61 docked with the Pirs unit at 10:40 p.m. Moscow time (1840 GMT) as planned," mission control spokesman Valery Lyndin was quoted by the Interfax news agency as saying.

"The docking has been successful. The crew will start unloading Progress after checking whether the docking unit is airtight," Lyndin said.

The freighter delivered more than 2.5 tons of cargo, including food, water, fuel and equipment.

The ISS will receive six computers to substitute those that went out of repair in the middle of June.

The computers, which were responsible for the ISS' orientation, were knocked out by strong electromagnetic field impacts after the crew of the U.S. shuttle Atlantis deployed new solar panels on the space station's exterior.

Russian cosmonauts Fyodor Yurchikhin and Oleg Kotov abolished the malfunction and reported the faults in all ISS systems, but the "revived" computers are still posing problems.

Another Russian supply ship Progress M-59 packed full with waste from the ISS was dumped in the Pacific Ocean on Wednesday.

Two supply ships are attached to the ISS at present. In December last year, Russian Mission Control embarked on the practice of not dumping Progress ships before the arrival of replacement cargo spacecraft, as it was done earlier, but to fully use their oxygen supply and to load them with the space station's waste to a maximum.

Apart from oxygen, specialists seek to make maximum use of the remaining fuel at the supply ships, leaving in them only a minimum necessary for their deorbiting.