| 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 two strap-on solid rocket boosters are lit as the Atlas 5 vehicle, designated AV-020, lifts off and begins a vertical rise away from Complex 41 at Cape Canaveral Air Force Station, Florida. |
|
|
| T+04:02 |
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+04:08 |
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+04:18 |
Centaur Ignition 1 |
| The Centaur RL10 engine ignites for the longer of the today's two upper stage firings. This burn will inject the Centaur stage and spacecraft into a parking orbit. |
|
| T+04:26 |
Nose Cone Jettison |
| The payload fairing that protected the LRO and LCROSS spacecraft during launch is separated once heating levels drop to predetermined limits. |
|
| T+14:01 |
Centaur Cutoff 1 |
| The Centaur engine shuts down after arriving in a planned parking orbit. The vehicle enters a short coast period before arriving at the required location in space for the second burn. |
|
| T+38:28 |
Centaur Ignition 2 |
| The Centaur re-ignites to accelerate the payloads out of the temporary parking orbit achieved earlier in the launch sequence. |
|
| T+43:23 |
Centaur Cutoff 2 |
| At the conclusion of its second firing, the Centaur will have propelled the LRO and LCROSS spacecraft on their trajectory toward the Moon. |
|
| T+46:12 |
LRO Separation |
| NASA's Lunar Reconnaissance Orbiter is released from the Centaur upper stage to begin its four-day cruise to the Moon. |
|
| T+46:16 |
LCROSS Sequence |
| The Centaur upper stage begins a safing sequence to deplete its remaining propellant and maneuvering fuel in preparation for the LCROSS mission. Official handover of the rocket stage to LCROSS is expected at T+plus 4 hours, 1 minute and 14 seconds. |
