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Atlas/Juno launch timeline
BY SPACEFLIGHT NOW
Posted: July 28, 2011


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T-00:02.7 Engine Start
The Russian-designed RD-180 main engine is ignited and undergoes checkout prior to launch.
T+00:01.1 Liftoff
The five strap-on solid rocket boosters are lit as the Atlas 5 vehicle, designated AV-029, lifts off and begins a vertical rise away from Complex 41 at Cape Canaveral Air Force Station, Florida.
T+01:44 Jettison SRBs
Having burned out of propellant approximately 10 seconds earlier, the spent solid rocket boosters are jettisoned to fall into the Atlantic Ocean. The separation event is staggered with two motors releasing first, then the other three about 1.5 seconds later.
T+03:25 Nose Cone Jettison
The payload fairing that protected the Juno spacecraft during launch is separated once heating levels drop to predetermined limits after passage through the atmosphere.
T+03:31 Forward Load Reactor Jettison
The Forward Load Reactor deck that supported the payload fairing's structure to Centaur upper stage is released six seconds after the shroud's jettison.
T+04:27 Main Engine Cutoff
The RD-180 main engine completes its firing after consuming its kerosene and liquid oxygen fuel supply in the Atlas first stage.
T+04:33 Stage Separation
The Common Core Booster first stage of the Atlas 5 rocket separates from the Centaur upper stage. Over the next few seconds, the Centaur engine liquid hydrogen and liquid oxygen systems are readied for ignition.
T+04:43 Centaur Ignition 1
The Centaur RL10 engine ignites for the first of two upper stage firings. This burn will inject the Centaur stage and Juno spacecraft into an initial parking orbit.
T+10:45 Centaur Cutoff 1
The Centaur engine shuts down after arriving in a planned parking orbit. The vehicle enters a half-hour coast period before arriving at the required location in space for the second burn.
T+41:33 Centaur Ignition 2
The Centaur re-ignites to accelerate the payload out of Earth orbit from the parking altitude achieved earlier in the launch sequence.
T+50:34 Centaur Cutoff 2
At the conclusion of its second firing, the Centaur will have propelled the Juno spacecraft on an Earth escape trajectory to begin a five-year planetary journey to Jupiter.
T+53:49 Spacecraft Separation
NASA's Juno space probe to study the origins and evolution of Jupiter is released into orbit from the Centaur upper stage to complete the AV-029 launch.

Data source: United Launch Alliance.



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