Photo: Jules1982 / Wikipedia

Breaking the sound barrier

The Bloodhound SSC car project aims to go well beyond breaking the speed of sound. Equipped with a Nammo rocket engine, they hope to achieve a truly astonishing speed: 1.000 miles per hour (1609 km/h). – At the edge of what is possible, admits chief engineer Mark Chapman.

Thorstein Korsvold, 6 May, 2019

21 years ago, driver Andy Green set the current land speed world record for a car: 763 mph (1228 km/h). Now he’s back as a driver for the new Bloodhound SSC car project, hoping to make the next big push.

The engine is made by Nammo – and it certainly isn’t the normal kind of engine for a car. It also powers space launchers.

– The engine is planned to be launched from the north of Norway and reach an altitude over 100 kilometers, says Adrien Boiron, principal hybrid rocket engineer at Nammo.

Last week, the Bloodhound engineering director, Mark Chapman, met with Nammo’s Boiron and held a presentation in Oslo.

See the whole presentation here (external link):

A digital car

Chapman explains that the biggest difference between today’s project and the record car from 1997, is how everything from aerodynamics to weight distribution have gone through an extensive computer analysis.

– Land speed records are all about technology. The only way you get faster, is to use better and better technology. We use confluential dynamics, aritificial intelligence, machine-based learning, virtual reality, all those technologies. We are a digital car. The way we are able to do 1000 mph, is the advance in computer technology and predictive analysis, says Mark Chapman.

When a car reaches the speed of sound, and beyond, physics also becomes very important to consider. The car wheels are nearly a meter in diameter, they go around with 10.500 revolutions per minute, and they weigh 95kg.

Centrifugal forces are so strong, 55.000 radial Gs, that a bag of sugar will weigh 55 tonnes at the rim of the wheel.

– 1.000 miles per hour is genuinely fast. It pushes the boundaries. We do have competitors, but our main competitor is physics. You do have things you run into at 1.600 kilometers per hour, that are at the edge of what is possible, Chapman says.

Same motor as a space launcher

For Nammo, the Bloodhound SSC project has been an exciting opportunity. Nammo’s hybrid rocket fit exceptionally well with the specifications required by the Bloodhound project.

– When they contacted us to see if we could help them, we had almost exactly matching components in terms of the engine side and the pump side. That was very exciting.

ROCKET POWER: Nammo’s hybrid rockets are designed for use in space launchers. But the Bloodhound SSC project is putting them to use in new ways. Photo: Nammo

Boiron believes hybrid rockets are the way to go.

– I’ve been working very closely on the development of this hybrid rocket motor, that we actually develop under contract for the European Space Agency (ESA) and the Norwegian space center. These motors are developed for use in space launchers. Hybrid rockets are the way to go in terms of flexibility, simplicity and potential low cost, Boiron says.