Faces of Ariane 6: Caroline

It takes thousands of people to design, develop, build and operate a complete space launch system. Here we highlight the people from all over Europe working on space transportation to ensure that Europe has independent access to space, to enjoy the benefits from space activities and share them with people of the world.

What is your name and role?

Caroline Aussilhou, Launch System Engineer in the Ariane 6 architect team, part of the Space Transportation Directorate of ESA, although I am seconded from France’s space agency CNES to work at ESA.

The word “launch system” and “architect” might seem out of place, as our team does not design buildings, but we oversee the whole Ariane 6 programme, being the broker between the designers and builders of the rocket, Arianegroup, and the designers and builders of the launch base, CNES.

Think of the Ariane 6 transport as a system like a car and the petrol station. They need to work together but they are two different things. As architects we ensure coherence, and optimisation between the two systems.

For example, although a rocket might seem to go straight up after liftoff, it’s actually difficult to make it go completely vertical, and technically not really necessary, there will always be some variation. But the rocket must clear the launch tower, or they would be damaged. The deviation from absolute straight is called the “lift-off corridor” and by the time the bottom end of your 60-m-tall rocket has reached the top of the launch tower it might be off-centre in a quite significant manner! For a rocket designer it’s easier to have a very large lift-off corridor, whereas the launch tower designer would prefer a rocket that went straight up, because then the connection arms can be shorter, and easier to engineer. This trade-off is just one of the many elements that we discuss a lot. For this example the result is we have a 13 m-long fuelling arm at the top of the launch tower – consider that the arms have to retract in less than hundreds of milliseconds, the engineering behind it is very impressive.

Another example is the ignition of the main stage for Ariane 6. Our rocket runs on liquid oxygen and hydrogen that exit the Vulcain 2.1 engine nozzle as gases. But these gases will float upwards because they are lighter than air and for lift-off, we don’t want to ignite going upwards towards the fuel tanks. To ensure the hydrogen and oxygen go down to the ignition system we built a nitrogen waterfall (N2 Torus), this inert gas traps and pulls the molecules down. This system contributes to avoid safety risks and help to ignite the Vulcain 2.1 engine: two jobs in one!

We in the system architecture teams make and enforce specifications. To quote Jean Claude van Damme: we make sure 1+1 is 11 :).

How long have you been involved in space transport and what are your tasks?

I have been involved in space transportation since 1999 when I have started as a liquid propulsion RAMS (Reliability, Availability, Maintainability and Safety) engineer at CNES in Evry, France. Then I was a ground Ariane 5 safety officer at the European Spaceport for CNES in French Guiana. On my return to mainland Europe, I became the head of the Launch System RAMS department at CNES in Paris, France. Five years after starting there, I became the Head of Launch Systems Conformity working for the French Space Operations Act. I did this for four years overseeing the Ariane 5, Soyuz and Vega rockets in the launcher’s directorate in Paris at CNES. The mission of my team with our Spaceport colleagues was to make risk assessments to allow the French Minister of Space to authorise (or not) launches from Europe’s Spaceport, the final “go” falls under responsibility of the Minister.

What is your educational background and prior work experience? How did you come to work on space transportation?

After my engineering studies at ENSMA, an aeronautical and mechanical school that is located near the Futuroscope theme park in Poitiers, France, my first career job was to work for IBM in their Microelectronic Division near Paris.  I was responsible for coordinating a production module for semiconductors working closely with the IBM development team in Fishkill near New York, USA. We had to design and produce parts of the semiconductor chips that ended up in all type of electronics.

Although the job at IBM was a great start for my career, I was always interested in space, so when I had the opportunity to work for CNES I took it and never looked back, even though I took a little decrease in salary, totally worth it.

What is the most notable or memorable moment during your time working on space transport?

Well, I started as a safety officer responsible for the Ariane 5 variant “Evolution Cryotechnique type A)” ECA, which didn’t work on its inaugural flight, and we were responsible for its return to flight in early 2005 after the failure in December 2002. I am very proud of the teams and the work we did, the ECA variant of Ariane was the most launched and at the time the most reliable rocket ever produced, based on Ariane 4 third stage launches experience.

I have had so many fun moments over the years, working with all the teams involved in launching rockets. I have had the pleasure of working on many inaugural or first flights. The first Soyuz flight from Europe’s Spaceport the first Vega flight and soon, the first Ariane 6 flight too. First flights are always more work as we must supply risk assessments and prove that the new rocket conforms to all laws, so we get a license to fly. The French law is important as worldwide the territory a rocket is launched from is held responsible for any consequences that come from the mission. We must prove that any risk for personal harm to citizens worldwide is less than one chance in 10 million. This is not a random number but the same chance of harm happening to anyone right now. As you read this sentence there is a statistical chance of 1 in 10 million that something bad might happen to you wherever you are in the world, and so we pledge no increase in risk. It is more complicated than this, but part of the essence of the French space law that entered into force in 2008.

What does it mean to you to be part of the larger team of rocket scientists and engineers?

It gives me great satisfaction! Although I am officially part of the CNES team on loan to ESA, the badge isn’t important, we are one team, the Ariane project team! It’s a marriage of reason, and it works.

What is one thing you’d like the European public to know about your job?

Our jobs are quite demanding and time-consuming working on so many subjects in parallel! We work hard, but we have a sense of humour as well, the final qualification review for Ariane 6 is called “SPQR” which officially stands for Smart Project Qualification Review but of course we are aware of its historical meaning. There are around 100 reviewers for the SPQR, looking at 10 volumes each over 2000 pages long, that describe the rocket and the launch pad connections in absolute detail. The review is lots of nights spent in hotels reviewing, reading, and meetings. It’s a “travail de titan”, a work of titans, but it needs to be done.

There is much more travel involved in my job than you might think, we are not sitting behind a desk all the time at all! I spent went for five missions to Europe’s Spaceport in French Guiana for the Ariane 6 combined tests, and in addition to that I also frequent the ArianeGroup assembly halls and test sites in Les Mureaux, France.

What’s the best thing about your job?

My work touches on so many different subjects! In a way I consider it as several different jobs. Then there’s the variety in workplaces too, so many places to physically work!

In essence the thing that is best about my job is the diversity. I spend time doing risk analysis as I worked on the combined tests in this field, and then there’s the qualification aspects as well as the coordination of the Launch System Design Definition File (DDF) and the Launch System Design Justification Files (DJF).

What do you do outside of your job to unwind, what are your hobbies, what do you do for fun?

I like to go to the cinema to unwind, but I am no intellectual when it comes to films. I like to see films that offer no complications, think romantic comedies, action films, blockbusters, anything where I can switch my brain of for an hour or two. I also enjoy aquabiking but the opportunities to do this are limited, for example when I am working at Les Mureaux I have to put it aside.

At this point in the operations, I don’t have much free time, if I have a stocked fridge and clean washing, I am happy now J. I am not complaining, deadlines are tight, and all together, as a team we accepted to assume our duty to make Ariane 6 happen successfully.

Do you have any advice for future generations interested in space exploration?

Study! Be curious! Read! Work and love!