United Launch Alliance managed to deliver to orbit on August 18th NASA’s third generation Tracking and Data Relay Satellite - TDRS-M.
Atlas V lifted off from SLC-41 at Cape Canaveral on August 18, at 12:29 UTC. Launch was delayed for 26 minutes due the technical problems with Centaur upper stage. RL-10C engine had problems with cooling, but ground service teams managed to track source of the problem. Issue was caused by ground lined connecting upper stage with launch tower. After resolving this problem countdown was resumed.
Punctually at 12:29 UTC RD-180 engine was ignited (T-2"7'") and Atlas V begun to raise over the SLC-41. Rocket performed course correction to set its trajectory to south-east. At T+1'32" rocket reached speed of 1 Ma and passed through the phase of flight when dynamic pressure reaches peak value. First stage was cut off at T+2'02" and after few seconds it was separated from Centaur. At T+4'26" payload fairing was jettisoned - it was done later comparing to previous flights; prolonged flight with payload fairing was necessary to protect extremely delicate mesh antennas of TDRS-M during crossing dense layers of atmosphere. After fairing separation Centaur fired its RL-10C engine for over 13 minutes to reach orbit of 183 km by 25680 km, 27.0° inclined. After first burn Centaur begun its coast phase crossing Atlantic and Sub-Saharan Africa. After flyby over Indian Ocean, Centaur performed second burn lasting 56 seconds at 1h48' and moved to injection orbit of 46444 km x 35790 km, 26.23° inclined.
TDRS-M was separated during flyby over Australia at T+1h54'. Satellite sent status report and confirmed correct separation and general good condition of the satellite. After series of tests satellite will move itself to GEO orbit using R-4D engine, where it will spend following fifteen years.