Another attempt to re-dock the Russian Progress M-15M space freighter to the International Space Station (ISS) will be made on Sunday, July 29, a spokesman for the Russian Mission Control Center said on Tuesday, after the spacecraft failed to re-dock with the ISS earlier in the day.

The unmanned space freighter, which arrived at the ISS in April, undocked from the station in the early hours of Monday in order to perform a series of engineering tests during re-docking designed to verify an upgraded automated rendezvous system.

The vehicle initially separated to a distance of about 100 miles from the station and held position for 24 hours before Tuesday's failed attempt to re-dock with the space station due to an apparent failure in the new Kurs-NA rendezvous system.

"Another attempt to dock Progress with the space station is scheduled for 5 am Moscow time (01:00 GMT) on July 29," the Mission Control Center spokesman said.

The failure of the Kurs-NA system triggered a passive abort - a standard procedure that took the Progress spacecraft to a safe distance of about 1.8 miles below the space station where it will remain until July 29.

Should another attempt to re-dock the freighter with the ISS using the modernized Kurs-NA system fail, the ISS crew may have to resort to using its time proven predecessor, the Kurs, for the re-docking mission to succeed, a source in Russia's space industry told RIA Novosti.

Alternatively, he said, the Progress freighter will be taken out of orbit and sunk.

Source: RIA Novosti