T-0:00:02.4	Engine start
	Atlas booster and sustainer engines are ignited and undergo checkout prior to liftoff. The two ground-start boosters will light a half-second before launch.
T+0:00:00	Launch
	The Atlas 2AS rocket, designated AC-156, lifts off and begins a vertical rise away from launch pad 36B at Cape Canaveral Air Force Station, Florida.
T+0:00:08	Roll Program
	During vertical ascent, Atlas begins a seven-second roll maneuver to align itself with proper flight azimuth. Following the roll, the Centaur inertial guidance system controls pitch and yaw programs.
T+0:00:58.8	Air-lit SRB Ignition
	The remaining two solid rocket boosters strapped to the Atlas are ignited once onboard computer software determines the two ground-start SRBs have burned out, about two seconds earlier.
T+0:01:15.6	Jettison Ground-Lit SRBs
	The two spent solid rocket boosters that were ignited on the ground are jettisoned to fall into the Atlantic Ocean. They had burned out at T+plus 55.6 seconds, but remained attached until the vehicle passes into preset safety zone.
T+0:01:56.3	Jettison Air-Lit SRBs
	Computer software will determine the air-start solid rocket boosters have burned all their propellant and should be jettisoned from the Atlas vehicle. The two SRBs will fall into the Atlantic Ocean.
T+0:02:43.1	Booster Engine Cutoff
	BECO occurs when axial acceleration of 5.0 g is obtained. Sustainer engine provides the continued boost toward orbit for the Atlas rocket.
T+0:02:46.3	Jettison Booster Package
	The bottom engine structure with the two booster engines is separated from the Atlas vehicle.
T+0:03:25.2	Jettison Payload Fairing
	The 14-foot diameter aluminum payload fairing that protected the ICO satellite during launch is separated once heating levels drop to predetermined limits.
T+0:05:02.5	Sustainer Engine Cutoff
	SECO is commanded once minimum residual propellant is sensed inside the Atlas booster stage.
T+0:05:04.5	Atlas/Centaur Separation
	The Atlas booster stage separates from the Centaur upper stage. Over the next few seconds, the Centaur engine nozzles are extended and liquid hydrogen and liquid oxygen systems are readied for engine ignition.
T+0:05:21.0	Centaur 1st Main Engine Start
	MES 1, the longer of the two Centaur firings begins to inject the upper stage and ICO spacecraft into a parking orbit with a perigee of 90.4 nautical miles and apogee of 5,455.2 nautical miles inclined 44.55 degrees.
T+0:10:45.7	Centaur Main Engine Cutoff
	MECO 1 occurs the Centaur engines are shutdown, arriving in a planned parking orbit. The vehicle begins a lengthy coast period to reach the high point of the orbit before the second Centaur burn.
T+1:49:14.6	Centaur 2nd Engine Start
	MES 2 occurs over the Southern Indian Ocean. The burn will propel the ICO satellite into the intended Medium Earth Orbit (MEO). The rocket's guidance computer will command the burn's conclusion once the proper orbit is achieved.
T+1:49:53.4	Centaur Main Engine Cutoff
	At MECO 2, the Centaur/ICO vehicle should be in the required transfer orbit with a perigee of 5,458.5 nautical miles, apogee of 5,460.4 nautical miles, inclined 44.91 degrees. Moments later, the stage begins aligning to the satellite separation attitude.
T+1:52:43.4	Spacecraft Separation
	The ICO F-2 global telephone and data relay satellite is released into orbit from the Centaur upper stage to complete the AC-156 launch.

Image and data source: International Launch Services and Lockheed Martin Astronautics.