| T-00:00 |
Liftoff |
| The ULA Delta 2 rocket's main engine and twin vernier steering thrusters are started moments before launch. The six ground-start strap-on solid rocket motors are ignited at T-0 to begin the mission. |
|
| T+01:17.1 |
Ground SRM Burnout |
| The six ground-start Alliant TechSystems-built solid rocket motors consume all their propellant and burn out. |
|
| T+01:19.0 |
Air-Lit SRM Ignition |
| The three remaining solid rocket motors strapped to the Delta 2 rocket's first stage are ignited. |
|
| T+01:20.5 |
Jettison Ground SRMs |
| The six spent ground-started solid rocket boosters are jettisoned in sets of three to fall into the Atlantic Ocean. |
|
| T+02:39.5 |
Jettison Air-Lit SRMs |
| Having burned out, the three spent air-started solid rocket boosters are jettisoned toward the Atlantic Ocean. |
|
| T+04:22.5 |
Main Engine Cutoff |
| After consuming its RP-1 fuel and liquid oxygen, the Rocketdyne RS-27A first stage main engine is shut down. The vernier engines cut off moments later. |
|
| T+04:31.0 |
Stage Separation |
| The Delta rocket's first stage is separated now, having completed its job. The spent stage will fall into the Atlantic Ocean. |
|
| T+04:36.5 |
Second Stage Ignition |
| With the stage jettisoned, the rocket's second stage takes over. The Aerojet AJ10-118K liquid-fueled engine ignites for the first of its two firings to boost the Dawn satellite. |
|
| T+04:41.0 |
Jettison Payload Fairing |
| The 9.5-foot diameter payload fairing that protected the Dawn spacecraft atop the Delta 2 during the atmospheric ascent is jettisoned is two halves. |
|
| T+08:58.3 |
Second Stage Cutoff 1 |
| The second stage engine shuts down to complete its first firing of the launch. The rocket and attached Dawn spacecraft are now in a coast period before the second stage reignites. |
|
| T+51:35.0 |
Second Stage Restart |
| Delta's second stage engine reignites for a short firing that accelerates the payload further. |
|
| T+54:14.5 |
Second Stage Cutoff 2 |
| The stage shuts down to complete its second burn. Over the next minute, tiny thrusters on the side of the rocket will be fired to spin up the vehicle in preparation for stage separation. |
|
| T+55:07.7 |
Stage Separation |
| The liquid-fueled second stage is jettisoned from the rest of the Delta 2 rocket. |
|
| T+55:44.7 |
Third Stage Ignition |
| The Thiokol Star 48B solid-fueled third stage is ignited to propel Dawn on its departure trajectory from Earth. |
|
| T+57:10.7 |
Third Stage Burnout |
| Having used up all its solid-propellant, the third stage burns out to completed the powered phase of the launch sequence for Dawn. |
|
| T+62:00.8 |
Dawn Separation |
| NASA's Dawn spacecraft is released from the third stage. The craft will visit and orbit the asteroids Vesta and Ceres over the next 8 years. |
