AC-204 launch timeline
Posted: February 19, 2002

T-00:02.73 Engine Start
Engine start The Russian-built RD-180 engine rumbles to life and builds to 74 percent thrust. A health check of eight engine parameters is performed by the rocket's onboard computer a half-second before liftoff.
T+00:00 Launch
Liftoff The maiden flight of Atlas 3B begins as the rocket is released from pad 36B at Cape Canaveral Air Force Station, Fla.
T+00:02 Roll and Pitch Programs
Roll During the vertical ascent Atlas completes a 7-second roll maneuver to align itself with proper flight azimuth. Following the roll, the rocket begins a pitch-over maneuver with Centaur inertial guidance system in control of pitch and yaw programs.
T+00:06 Throttle Up
Throttle up The RD-180 engine is throttled up from its liftoff thrust of 74 percent to over 90 percent after the rocket clears the launch pad 36B tower.
T+00:35 Throttle Down
Throttle down The RD-180 engine is throttled down to a thrust level of about 67 percent to ease the rocket through the dense lower atmosphere.
T+01:05 Through Max-Q
Transonic The rocket passes through maximum dynamic pressure and goes transonic. The RD-180 now throttles back up to its cruise setting of about 87 percent thrust, ramping up to 5.5 g's.
T+02:50 Throttle Down
Throttle down To prepare for the upcoming engine shutdown, the RD-180 is once again throttled down, this time to 47 percent.
T+03:01.3 Booster Engine Cutoff
BECO The RD-180 engine is commanded to cut off once minimum residual propellant is sensed inside the Atlas booster stage.
T+03:07.6 Atlas/Centaur Separation
Atlas separation Six seconds after engine shutdown, the Atlas booster stage separates from the Centaur upper stage. Over the next 11 seconds, the Centaur liquid hydrogen and liquid oxygen systems are readied for engine ignition and the nozzle extensions are deployed.
T+03:18.6 Centaur 1st Main Engine Start
MES-1 MES 1, the longer of the two Centaur firings, begins to inject the upper stage and EchoStar 7 communications satellite into a low altitude parking orbit around Earth.
T+03:36.3 Jettison Payload Fairing
Fairing separation The 14-foot diameter aluminum payload fairing that protected the EchoStar 7 satellite during launch is separated once heating levels drop to predetermined limits.
T+08:49.8 Centaur Main Engine Cutoff
MECO-1 MECO 1 occurs when the single Centaur engine is shut down, with the rocket arriving in a planned parking orbit. The vehicle begins a coast period over the mid-Atlantic before arriving at the required location in space for the second burn.
T+22:40.4 Centaur Main Engine Re-start
MES-2 MES 2 occurs over the Atlantic Ocean between the African Ivory Coast and Ascension Island before the rocket passes just north of the equator. The burn accelerates the vehicle and satellite into the required geosynchronous transfer orbit.
T+24:47.9 Centaur Main Engine Cutoff
MECO-2 At the point of MECO 2, the Centaur/EchoStar 7 vehicle should be in the required transfer orbit, completing the powered phase of the launch. The stage then begins aligning to the satellite separation attitude.
T+28:27.9 Spacecraft Separation
Spacecraft separation The EchoStar 7 direct-to-home TV broadcasting satellite is released into space from the Centaur upper stage to complete the AC-204 launch -- the maiden flight of Lockheed Martin's Atlas 3B rocket.

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

Flight data file
Vehicle: Atlas 3B (AC-204)
Payload: EchoStar 7
Launch date: Feb. 21, 2002
Launch window: 7:13-8:14 a.m. EST (1213-1314 GMT
Launch site: SLC-36B, Cape Canaveral AFS, Fla.
Satellite broadcast: Telstar 6, Trans. 22, C-band

Pre-launch briefing
Launch timeline - Chart with times and descriptions of events to occur during the launch.

Ground track - See the trajectory the rocket will follow during its flight.

Atlas 3B vehicle data - Overview of the rocket to be used in this launch.

The RD-180 - Facts and figures about the Russian-built engine to power Atlas 3.

EchoStar 7 - Description of this direct-to-home TV broadcasting satellite.

Atlas index - A directory of our previous Atlas launch coverage.