[8] The incident was caused by a blocked fuel line leading to the gas generator of the third-stage RD-0110 engine of the spacecraft's Soyuz-U booster.

[9] A Russian commission blamed the Progress M-12M failure on a single human error, and put additional procedures in place to prevent the problem from recurring.

The Soyuz crew entered the ISS at around 6:39 GMT, and were greeted by Expedition 29 crewmembers Mike Fossum, Sergei Volkov and Satoshi Furukawa.

Burbank, Shkaplerov and Ivanishin received congratulatory satellite calls from Russian dignitaries and family members before participating in a safety briefing led by Expedition 29 commander Fossum.

[12] Soyuz TMA-22 undocked from the ISS on 27 April 2012 at 8:15 AM (GMT), carrying Burbank, Shkaplerov and Ivanishin, and landed safely near Arkalyk, Kazakhstan, at 11:45 AM the same day.