Although no definite reason was given, it is assumed that the failure in the new Kurs-NA rendezvous system was to blame for the failure to dock of the Russian Progress 47 spacecraft.
The spacecraft was undocked to the ISS at 4:26 p.m. EDT on Sunday, July 22nd, for the self-rendezvous test of the new Kurs-NA rendezvous system.
The Kurs-NA automated rendezvous system is being tested on the Progress 47 spacecraft.
It has upgraded electronics over the previous system, which was designed to consume less power and to be safer than its predecessor. (corrected 7/26/12)
The failure occurred when commands were being sent to the Kurs-NA system to activate itself. This occurred at about 8:23 p.m. EDT on Sunday, at about 15.2 kilometers (9.4 miles) behind the Space Station.
When the commands were sent, a failure was announced, which triggered a "passive abort" that ended the test.
A second attempt will be made on Sunday, July 29, 2012, at about 6 p.m. Eastern Daylight Time (EDT). Later that day, ISS crewmembers Joe Acaba, of NASA, and Akihiko Hoshide, of JAXA, are prepared to grapple the HTV-3 cargo craft with the ISS Canadarm 2, and then berth it to the Space Station at the U.S. Harmony port.
An earlier attempt is not possible because the Japanese are bringing in its HTV-3 supply ship early on Friday, July 27, 2012, for a rendezvous with the ISS.
The YouTube video shows the following: "The Progress (M-15M) 47 uncrewed cargo ship, emptied of supplies and filled with trash for disposal, undocked from the International Space Station. Russian flight controllers tested a new automated rendezvous system, known as Kurs-NA, to perform the maneuver more safely and efficiently. The Progress will redock on Monday to further test the new system" (http://www.youtube.com/watch?v=PIX-ge9LAUw&;feature=player_embedded).