8 fascinating facts about an Ariane 5 rocket launch

An Ariane 5 rocket will soon take a new satellite up into orbit above the Earth for Inmarsat’s European Aviation Network. Once orbiting and fully operational, it will make more robust, faster broadband in European skies a reality.

Ahead of the launch, here are eight facts you may not know about an Ariane 5 rocket – from its total mass to the potentially deadly force of its sound waves.

It weighs 780 tons

Rocket launching

Though the Ariane 5 is only around five stories high – about twice the height of Buckingham Palace but smaller than Big Ben or the London Eye – it packs a lot of weight. Well, mass specifically. It has a mass of 780 tons. That’s roughly 61 London Buses or 390 adult male elephants.

Its payload is a maximum of 10 metric tons

Satellite under construction

This is what it carries when heading to geostationary transfer orbit. That means the cargo only comprises about 1% of the rocket’s total weight. For this launch, the Ariane 5’s payload is a new satellite for the European Aviation Network.

Each launch costs €150M

Image of rocket

It sounds like a lot of money but remember this is, quite literally, rocket science we’re talking about. Amazingly, it’s not far off the cost of an Airbus A320, which stands at around €98M.

A rocket launch is basically a controlled explosion

When the Ariane 5 lifts off it will need 1340 tons of thrust to do so. Tons of burning fuel inside the rocket supply that thrust. It’s an explosion that generates a huge amount of force with very narrow margins for error. Rocket launches merely channel and control those forces.

Rockets need to travel at over 25,000mph

Rocket blast-off

This is what’s called a rocket’s ‘escape velocity’ – the speed it needs to achieve to break free from Earth’s gravity. That’s seven miles per second, by the way.

Its jettisoned engines fall into the ocean

Post launch vapour trails from rocket

At 42 miles and 124 miles above the Earth respectively, Ariane5’s SRBs (Solid Rocket Boosters) and then its main Vulcain engine are jettisoned from the rocket and fall back to Earth. In this case, they fall into the South Atlantic Ocean from where they can be recovered, as you can see here.

The sound of a rocket’s take-off could knock down a building

Rocket under test

It’s one of the things scientists must consider when building a new rocket, such as NASA’s new SLS rocket. During testing, NASA engineers have determined that the acoustic energy produced at a rocket launch could knock down a building.

Water jets are used as sound suppression

Image of water jets

With the above point in mind, engineers have turned to water to make the acoustic energy of a rocket launch a little safer. Those water jets you see spraying around a rocket on the launch pad? They’re not cooling anything – the liquid actually dampens the sound wave of the launch by increasing the resistance on it, slowing the sound wave down.