Space travel: test flight of the candle wax rocket | tagesschau.de

The SR75 rocket from the German company HyImpulse is special: For the first time, paraffin, the main ingredient in candle wax, was used as fuel – with success.

It was probably the first purely privately financed rocket launch from Germany: the paraffin-powered rocket was developed by the private company HyImpulse. It is based in Neuenstadt am Kocher, near Heilbronn (Baden-Württemberg). The company’s 65 employees have developed the paraffin-oxygen hybrid drive until it is ready for launch.

The paraffin rocket has not yet been tested into space

However, the rocket was launched at the other end of the world: HyImpulse launched its rocket from the Australian Koonibba rocket test site on Friday morning European time. A maximum height of 60 kilometers was planned. According to the company, it will take a few days until the rocket is recovered and the data is evaluated. Only then can it be said whether the planned height of 60 kilometers has been reached. The limit to space at 100 kilometers will only be exceeded on later flights. The launch of the rocket had been postponed several times due to weather.

This is how the candle wax drive works

There is a block of solid paraffin in the rocket body. This is riddled with many holes. Liquid oxygen is passed through these holes. The two substances react with each other. The resulting hot gas powers the rocket.

Candle wax rocket also has disadvantages

However, the solid fuel block never burns completely evenly. This can cause the rocket to begin vibrating in flight, which can damage and even destroy it. Switching off and re-igniting a hybrid rocket very quickly in flight is also not that easy – but this ability is required when it comes to achieving precisely defined speeds in order to be able to launch spacecraft onto equally precisely defined orbits.

Candle wax powered rocket cannot explode

The advantages of candle wax technology are its low cost. In addition, the risk of the rocket exploding is zero. Over the past few weeks, it was able to be transported safely from Neuenstadt near Heilbronn to Australia by ship in a loaded condition. The company had booked a week of launch time at a rocket test site there.

successor The rocket is intended to launch satellites into space

After the successful first flight, flights into space above 100 kilometers can now take place. However, the rocket cannot enter an orbit around the Earth – only a successor model should achieve the necessary speed and then launch satellites weighing up to 600 kilograms into space. A first start is planned for the end of 2025.

The rocket’s candle wax propulsion has potential

HyImpulse already has orders worth more than 100 million euros on its books for its flights into space. Russia is currently no longer a contractor for satellite transport due to sanctions. And the new European rockets Ariane 6 and VEGA-C are being launched after years of delay.

That’s why commercial rocket builders from Germany believe they have a chance of snatching some of the big cake from the American industry leader SpaceX. In addition to HyImpulse, these are the companies Isar Aerospace in Munich and the Rocket Factory in Augsburg, which also has its Rocket One almost ready to take off.

While the costs for transporting satellites into space with conventional small rockets are around 12,000 to 25,000 euros per kilo of payload, the costs in the first expansion stage of the rocket at HyImpulse are expected to be around 6,500 euros per kilo – and HyImpulse expects a further cost reduction in the long term .

This is also necessary if HyImpulse wants to survive the next revolution in satellite transport that is emerging. SpaceX’s Starship will be able to carry several hundred satellites into space in a single launch and is targeting costs of just several hundred dollars per kilogram.