| T-00:00.0 |
Liftoff |
| The 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+01:03.0 |
Ground-Lit SRM Burnout |
| The six ground-start Alliant TechSystems-built solid rocket motors consume all their propellant and burn out. |
|
| T+01:05.0 |
Air-Lit SRM Ignition |
| The three remaining Alliant TechSystems-built solid rocket motors strapped to the Delta 2 rocket's first stage are ignited. |
|
| T+01:06.0 |
Jettison Ground-Lit SRMs |
| The six spent ground-started solid rocket boosters are jettisoned in sets of three at T+66 and T+67 seconds to fall into the Atlantic Ocean. |
|
| T+02:11.5 |
Jettison Air-Lit SRMs |
| Having burned out, the three spent air-started solid rocket boosters are jettisoned toward the Atlantic Ocean. |
|
| T+04:20.7 |
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+04:29.7 |
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+04:34.2 |
Second Stage Ignition |
| With the stage jettisoned, the rocket's second stage takes over. The Aerojet AJ118-K liquid-fueled engine ignites for the first of two firings needed to place the upper stage and GPS 2R-4 satellite into the proper orbit. |
|
| T+04:50.0 |
Jettison Payload Fairing |
| The 9.5-foot diameter composite payload fairing that protected the GPS 2R-4 satellite atop the Delta 2 during the atmospheric ascent is jettisoned is two halves. |
|
| T+10:44.7 |
Second Stage Cutoff 1 |
| The second stage engine shuts down to complete its first firing of the launch. The rocket and attached GPS 2R-4 spacecraft are now in a 9-minute coast period before the second stage reignites. |
|
| T+19:53.7 |
Second Stage Restart |
| Delta's second stage engine reignites for a short firing to continue the journey to space. |
|
| T+20:29.1 |
Second Stage Cutoff 2 |
| The second stage shuts down after a 35-second burst. 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+21:19.1 |
Second Stage Separation |
| The liquid-fueled second stage is jettisoned from the rest of the Delta 2 rocket having completed its role in the GPS 2R-4 launch. |
|
| T+21:59.1 |
Third Stage Ignition |
| The Thiokol solid-fueled third stage is ignited to complete GPS 2R-4's delivery into its intended orbit around Earth. |
|
| T+23:25.5 |
Third Stage Burnout |
| Having used up all its solid-propellant, the third stage burns out to completed the powered phase of the launch sequence. Over the next two minutes, two small yo-yo-like structures are released from the third stage to reduce the spinning motion the Delta rocket and GPS 2R-4 are experiencing in preparation for satellite separation. |
|
| T+25:19.1 |
GPS 2R-4 Separation |
| The U.S. Air Force's NAVSTAR Global Positioning System Block 2R-4 spacecraft is released into space full a vacant position in the GPS military navigation network. The Delta should have placed the satellite into a transfer orbit with a high point of 10,998 nautical miles and low point of 101 nautical mile. The satellite will circularize its orbit. |
Track the major launch events for the Delta 2 rocket carrying the GPS 2R-4 satellite on Spaceflight Now's interactive flight profile page (requires JavaScript).