At 3:13 AM EDT today the Soyuz MS-04 was launched from Baikonur to begin a four orbit, six hour journey to dock with the International Space Station (ISS).
For the first time since October 2005, the vehicle was only carrying two crew members instead of the typical three. This is due to a change made by Russian to switch to only having two crew members on board ISS.
Once in orbit, the vehicle deployed its Solar Arrays and KURS automated docking antennas and begun a series of approach burns allowing the crew to perform the accelerated docking path.
When the vehicle returns in September it will be carrying three crew members back to Earth as NASA Astronaut Peggy Whitson will be staying on the station to ensure a three person crew remains.