It was third time lucky for the Atlas V rocket that launched from Cape Canaveral at 5:15pm EST on Friday 24th February 2012. After being scrubbed for high-level winds on the first attempt and disturbed weather on it second try it finally took to the skies after a layover of a few days.
Two days before the launch the weather was predicted to be only 20% for a favourable launch. This improved to 60% the day before, 80% on launch day and ended up at 90% heading into the terminal countdown. Obviously the 90% converted into 100% as the Atlas V carrying the US Navy MUOS-1 communications satellite streaked into the sky on its way to a orbit 22,000 miles above the Earth.
Our video catches the launch sequence starting at T-5 seconds with the sun sinking in the west silhouetting the rocket against the blue sky.
Continue reading for our launch report and two galleries of launch pad photos…
The Atlas V was in the 551 configuration which consists: the Atlas V common core booster; 5 solid rocket boosters and a single Centaur upper stage which is enclosed in a 5 Meter Payload Fairing. When empty the Common Core Booster is copper coloured but as the rocket is fuelled the common core is covered in frost making the entire rocket white.
The MUOS-1 space craft is the first satellite in the US Navy Mobile User Objective System constellation that will eventually be completed with 4 active satellites and one standby spacecraft. Each satellite can service a third of the Earth providing 3G voice, data and video communications for deployed units across the globe.
Just before the countdown came out of the T-4 minute hold the Launch Team were polled for launch readiness. Today we heard “GO” from each of the team members which released the countdown allowing the rocket to launch right at the opening of the launch window. Setting the launch for 22:15 Zulu (GMT) the countdown resumed at 5:11 EST and proceeded, this time uninterrupted, all the way to T-3 seconds when the booster engine ignition is started with the rocket blasting off at T+1 second.
Just prior to the booster engine ignition the water jets of the sound suppression system are activated spraying water over the pad and the flame trench. As the rocket engine comes to life there is a huge ejection cloud from the flame trench, which can be clearly seen in the video, particularly in the slow motion section. A second later with the SRBs lit the Atlas V rocket lifts off and roars into the skies on its way into orbit, leaving the camera engulfed in first exhaust, and then sticky wet particulate.
Just over 30 seconds into the flight the rocket had broken the sound barrier as it passed mach 1. At 45 seconds the rocket passes MaxQ when it is subject to the maximum dynamic pressures during the launch and the engines start to throttle up. At T+1m30s the solid rocket boosters burn out and 3 seconds later the first 3 SRBs are jettisoned, followed a second or so by the last 2 SRBs.
At this time the rocket is now 38 miles high and 50 miles down range from the launch pad travelling at over 4700MPH. Tracking showed the Atlas V to be right in the middle of the range. The next event was the payload fairing separation at T+3m21s with everything happening on time perfectly. By now the rocket is over the Bahamas, when the Main Engine Cutoff (MECO) occurred. Separation of the Atlas Booster which tumbled back to earth and the ignition of the first of 3 Centaur engine burns happened next.
The first centaur burn lasted just over 7 minutes taking the Spacecraft into orbit around the Earth. Next there was a cruise stage taking us to T+20m49s before the engine was restarted for the second time just off the coast of Africa. This was 6 minute burn before the Centaur was shut down again before another coast period for 2.5 hours.
The final Centaur burn took place about T+2h57m and lasted just under a minute. Four minutes after the final burn the MUOS-1 Spacecraft separated and the Satellite was in its target orbit ready to be tested prior to commissioning at a further date.
Our first section of the photo gallery is taken looking north to the launch pad with the sun setting in the west. You can clearly see the launch sequence as the sound suppression system activates, the flame trench spews ejaculate as the engine start, the boosters ignite and the rocket finally lifts off.
In the second section our camera points west into the setting sun. The Atlas V forms a silhouette as we witness the launch sequence from this angle watching as the sun is outshone by the flame of the rocket engine.