Soyuz Crew Docks with ISS After Two-Day Delay

Two days later than expected, the Soyuz TMA-12M spacecraft successfully docked with the International Space Station (ISS) at 7:53 pm Eastern Daylight Time (EDT) tonight, March 27.

Russia’s Alexander Skvortsov and Oleg Artemyev and NASA’s Steve Swanson launched from the Baikonur Cosmodrome in Kazakhstan at 5:17 pm EDT on Tuesday expecting to dock with the ISS about 6 hours (4 orbits) later.   A series of engine burns is needed for the Soyuz to reach the ISS and the third burn did not take place because the Soyuz was not in the expected orientation.

The 4-orbit rendezvous profile has been in use only since last year – for the last four missions.  The traditional route to the ISS takes 34 orbits over two days and that approach remains as a backup plan.  Computers automatically switched to the 34-orbit profile when the third engine burn failed to occur.

Apart from that glitch, everything has worked perfectly on the flight.   The Soyuz docked with the ISS five minutes ahead of schedule.  The hatches will open and the crew will enter the ISS around 10:40 pm ET tonight after leak checks and other tasks are competed.  They will join three ISS crewmembers already there:  Japan’s Koichi Wakata, currently in command of the ISS, NASA’s Rick Mastracchio, and Russia’s Mikhail Tyurin.