Russian cargo ship fails to dock with ISS

Posted by Emma Woollacott

A Russian attempt to redock the ISS Progress 47 resupply spacecraft to the International Space Station has failed, thanks to a a problem with the new Kurs-NA rendezvous system.

"A failure of an unknown nature occurred and caused the Progress's on-board computers to self abort and put the spacecraft into a passive abort trajectory," said NASA mission commentator Dan Huot.

The exact cause of the failure isn't known - but it's potentially a blow for NASA's current strategy of using Russian ships to resupply the ISS.

A second attempt may be made later today, depending on whether ISS officials decide to allow Japan's HTV3 vehicle to be grappled and berthed first.
If so, the next opportunity would be this coming weekend.

The test was going well until about the time that the new Kurs-NA rendezvous system was to be engaged. As commands were being issued to activate the system, a failure occurred, triggering a passive abort.

As a result, in case anything else should go wrong, Progress 47 will fly around 1.8 miles below the station to a safe distance from the station, where it will remain until another attempt is made to re-rendezvous with the space station.

The vehicle initially undocked from the station July 22 in order to perform a series of engineering tests during re-docking. These were designed to verify the upgraded automated rendezvous system that's central to future dockings of Russian vehicles to the space station.

If a second attempt fails, the ISS crew will likely revert to using the Kurs-NA system's predecessor, the Kurs - or else scrap the ship altogether.