The initial launch date for Rosetta was 07:36:49 UT on 26 February 2004. However, an initial delay due to adverse weather, and a subsequent delay due to a technical issue with the launch vehicle, pushed the launch date back by five days.
The launch trajectory for the mission was somewhat unusual for Ariane, because of the precise requirements of the Rosetta spacecraft. The two solid boosters burnt for around 139 seconds before being jettisoned. The main stage of the rocket continued to burn for around another 7 minutes before cut off and separation.
At this point the upper stage, plus Rosetta, entered into a balistic phase. The combined upper stage and spacecraft travelled in an elliptical orbit with an apogee altitude of around 4000 km and a perigee altitude of 45 km.
This balistic phase lasted around 1 hour 45 minutes. At the end of this phase the upper stage was ignited for around 17 minutes - accelerating the Rosetta spacecraft up to esacpe velocity and ultimately into an Earth escape trajectory.
Launch Countdown and Flight Events
|-11h 30m 00s||Start of final countdown|
|- 7h 30m 00s||Check of electrical systems|
|- 3h 20m 00s||Chilldown of Vulcain main stage engine|
|- 1h 10m 00s||Check of connections between launcher and telemetry, tracking and command systems|
|- 7m 00s||All systems go report, allowing start of synchronized sequence|
|- 4m 00s||Tanks pressurized for flight|
|- 1m 00s||Switch to onboard power mode|
|- 04s||Onboard systems take over|
|- 03s||Unlocking of guidance systems to flight mode|
|H0||Ignition of the cryogenic main stage engine (EPC)|
|ALT (km)||V. rel. (ms-1)|
|+ 7.0s||Ignition of solid boosters||0||0|
|+ 13s||End of vertical climb and beginning of pitch rotation (10 seconds duration)||0.08||33.6|
|+ 17s||Beginning of roll maneuver||0.29||66.1|
|+ 2m 19s||Jettisoning of solid boosters (H1)||66.2||2086.0|
|+ 3m 11s||Jettisoning of fairing||105.8||2315.0|
|+ 8m 19s||Acquisition by Natal tracking station|
|+ 9m 50s||Extinction of main cryogenic stage||169.3||8098.3|
|+ 9m 56s||Separation of main cryogenic stage||173.4||8117.2|
|+ 9m 57s||Beginning of balistic phase (H2)|
|+ 12m 10s||Acquisition by Ascension tracking station|
|+ 21m 50s||Acquisition by Malindi tracking station (Kenya)|
|+ 48m 10s||Acquisition by Dongara tracking station (Australia)|
|+ 1h 46m 13s||Acquisition by South Point tracking station (Hawaï)|
|+ 1h 54m 47s||Ignition of EPS (H3)||652.6||7591.3|
|+ 2h 11m 04s||Acquisition by Kourou tracking station|
|+ 2h 11m 48s||Injection of EPS||1091.8||10410.1|
|+ 2h 11m 48s||Beginning of Rosetta orientation||1091.8||10410.1|
|+ 2h 13m 30s||Separation of Rosetta (H4.1)||1364.3||10228.9|
|+ 2h 50m 00s||End of Arainespace Flight 158 mission||6370||8050|
Early Mission Activities
2 March 2004 09:54 UT
2 hours and 58 minutes after launch, the solar array deployed.
2 March 2004 10:12 UT
'Sun Acquisition Mode' attained - pointing the solar arrays in the direction of the Sun.
2 March 2004 11:30 UT
Star-trackers' check completed and activated.
Three of the four reaction wheels were switched on exactly as planned.
3 March 2004 02:23 UT
Completion of deployment of high-gain antenna.