SIRTF launch timeline
SPACEFLIGHT NOW
Posted: April 14, 2003

T-00:00 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+01:16 Ground SRM Burnout
The six ground-start Alliant TechSystems-built solid rocket motors consume all their propellant and burn out.
T+01:19 Air-Lit SRM Ignition
The three remaining solid rocket motors strapped to the Delta 2 rocket's first stage are ignited.
T+01:21 Jettison Ground SRMs
The six spent ground-started solid rocket boosters are jettisoned in sets of three to fall into the Atlantic Ocean.
T+02:40 Jettison Air-Lit SRMs
Having burned out, the three spent air-started solid rocket boosters are jettisoned toward the Atlantic Ocean.
T+04:24 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+04:32 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+04:37 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 boost SIRTF into an Earth-trailing orbit.
T+04:42 Jettison Payload Fairing
The 9.5-foot diameter composite payload fairing that protected SIRTF atop the Delta 2 during the atmospheric ascent is jettisoned is two halves.
T+07:17 Second Stage Cutoff 1
The second stage engine shuts down to complete its first firing of the launch. The orbit achieved should be 90 miles circular with an inclination of 31.5 degrees. The rocket and attached SIRTF spacecraft are now in a coast period before the second stage reignites.
T+38:35 Second Stage Restart
Delta's second stage engine reignites for the firing to propel SIRTF into its heliocentric orbit.
T+43:11 Second Stage Cutoff 2
The second stage shuts down to complete the powered phase of launch. The stage will perform a maneuver to the proper attitude for payload deployment.
T+48:10 SIRTF Separation
NASA's Space Infrared Telescope Facility is released into space from inaugural Boeing Delta 2 Heavy rocket.

Data source: NASA.


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