One worked on Bugatti’s fastest supercar, the other on the NASA Solar Sail – both are pushing humankind’s drive to break boundaries
Current affairs | 4 January 2021

Frank Heyl is Deputy Design Director at Bugatti, developing the world’s fastest cars, including the Bugatti Chiron Super Sport 300+ – officially the world’s fastest sports car, breaking the 300-mile-per- hour barrier and hitting an unprecedented 490,4 km/h in 2019. Les Johnson is Deputy Manager for the Advanced Concepts Office at NASA, designing some of the most forward-thinking concepts to propel rockets further and more precisely into the unknown. Both are at the forefront of their respective industries, pushing humankind’s constant drive to break boundaries and explore new territory.

Les Johnson: Tell me where your passion for cars stems from.
Frank Heyl: I’m a complete petrolhead. An absolutely hopeless case. Everything in my life is about cars, engines, going to racetracks. I made my hobby my job. I’ve always been interested in technology and how things work, which has become an essential part of my job as we’re not just working on any car, but one that can go 300mph. Therefore there’s a lot of technology involved, and a lot of aerodynamic research and knowledge. I’m also inspired by other machines and vehicles, especially jets and fighter jets – also what conventionally led to NASA, the X-planes program [a series of experimental US aircraft and rockets used to test new technologies and aerodynamic concepts established in 1944]. I studied at the Royal College of Art in London and my degree thesis was about supersonic aircraft. I lived in Kensington, directly in the flight path of Heathrow and Concorde, I actually saw the last one fly over my house – always an incredibly loud experience. I was always dreaming of bringing that back into civil engineering, to travel supersonically. So I teamed up with the German Aerospace Center to work on a concept that was initially introduced by NASA called the oblique flying wing, where you have a top-decker aircraft and you rotate the wing to reduce the drag. From there, super-fast aircraft kept inspiring my work.

LJ: I was seven years old when Neil Armstrong walked on the moon, I’m 58 now. My parents woke me up and told me I had to watch. I had no idea what was going on, but I realised he was walking on the moon and then I started following everything around the space programme. I started reading science fiction, which is a dangerous thing for a young person to do [laughs], and when I was ten or eleven, I decided I wanted to be a NASA scientist. I had no idea what a scientist did, but by golly, you had to be one to work on the stuff that lets people walk on the moon [laughs]. I applied to work at NASA after grad school but didn’t get the job, so I took one with a company working on various space applications in the area, Mountain Brook, Alabama, near Huntsville, Alabama, where the Marshall Space Flight Center is and where I’m currently based. I tried again and got the job. So that’s been my career, which is now 30 years on, and, like you say your job is your hobby, I’m the same [laughs]. I spend my time talking about the challenges of in-space propulsion. With rocket technology, we’re getting more efficient, more reusable, but we’ve really reached the limits of what you can do with chemical propulsion in terms of performance with rockets. I decided around 25 years ago that I wanted to work on advanced propulsion that isn’t rocket-based, because that’s the way we’re going to get the speed we need in order to cover the vast distances to explore space. So I began working on various propulsion technologies which, at first glance, people think are very unimpressive low-thrust, not very exciting to watch.

But long term, it’ll get you to tremendous speeds, more than any rocket. These advanced propulsion methods are finally starting to come into use for in-space exploration – beyond Earth’s orbit, beyond where the rocket takes you to get you into space. Right now, I’m the lead on the solar sail mission, which I think is ultimately how we’re going to reach the stars – it’ll be the technological descendants of what I’m working on now. I also enjoy watching an impressive car race [both laugh]. Talladega [Superspeedway] isn’t far from my home, only about 150 miles from here, and it’s always big news when they’re racing down there. Tell me about your work at Bugatti.
FH: Well, the first Veyron exceeded 400km/h and this goal came from the ingenious engineer and long-time CEO and Chairman of the Volkswagen Group, Ferdinand Piëch, who was racing in the 60s with his team Porsche on a programme called 917 with the purpose to race Le Mans. . So you could really get far in the race if you had the fastest car along that straight. That’s where the goal came from. Now it’s a bit different because the chicanes were introduced as the cars became too fast for racing. Once we had that technical base, we said we could top our own record, because it stood for a few years. So that’s what we did with the Veyron Super Sport [officially the world’s fastest sports car at the time after reaching 431,072km/h (268 mph) in 2010] and the Chiron. During my time at Bugatti, I’ve learnt many things about aerodynamics, the idea to put a long tail on the car, for example, came from the purpose of reducing drag. As you’ll know, with aerodynamics there’s never that one thing you find that fixes it all, it’s a lot of little things that add up to the overall result. It’s absolutely fantastic to be able to pick out these concepts, work them out and see them function.

“At Le Mans, they didn’t used to have the Coca-Cola and PlayStation chicanes, it was just an enormous straight… that’s where the [record speed] goal came from.”

Solar Sail artist impression, image courtesy of NASA

LJ: I’m listening to you talk about the challenges that you face and I’m almost grinning [laughs]. The reason is that you’re dealing with lots of forces and complex interactions on a scale that’s very different – it might surprise you how different. I’m working on the solar sail, which is a propulsion system that’s basically a large, lightweight reflector. It looks like a sheet of aluminium foil, only much thinner and much lighter, it’s a very thin plastic film with aluminium on it and it reflects sunlight. You deploy this long thin sheet… and I mean big.

The NEA Scout project I’m the lead for, which is to launch next year, once it gets out into space it’ll deploy a solar sail that is 86 square metres in area and two and a half microns thick – about the thickness of a human hair. It’s supported by four booms that are each 7.3 meters long, sort of like you’d imagine on a sailing ship and it’s the sun’s light reflecting on the sail that pushes it. You don’t feel it on Earth because it’s a very small push, but sunlight exerts pressure. What we want to do is attach this 86 square metre sail to a small spacecraft weighing only 13kg. Then we’re going to use the sunlight reflecting from the sail to push our spacecraft to rendezvous with an asteroid. So the rocket gets us into space, then after the rocket kicks us off, we unfold our sail and over two-and-a-half years we’ll use the reflected sunlight to take us to the asteroid. We steer by tipping and tilting the sail to change the angle. It’s just like sailing a ship.
FH: It’s absolutely intriguing.

Bugatti Chiron, image courtesy of Bugatti

“One of these days these sails are going to be square kilometres in size. That’s in 100 years or so, and that will be sending probes to other stars, in my opinion.”

LJ: Getting to the difference in scale of what we deal with, I think you’ll be amused. When we’re flying this, our instantaneous acceleration is 0.06 millimetres per second squared. So how many Earth g’s [standard gravity] do you get in your car acceleration?
FH: Nearly two.

LJ: One g is what? 9.8 metres per second? Well our acceleration is six one-hundredth of a millimetre per second squared. So our acceleration is nothing like you experience. But it stays constant over years, so our sail is going to add five kilometres a second to the speed of our spacecraft over the flight. And that’s huge [laughs]. So what, that’s about 18,000mph. And the vast forces you’re talking about, drag, aerodynamic forces, frictional forces, we don’t have those, we’re worried about disturbances in the range of micro to millinewtons, because over time those can lead to us losing control. So we’re operating in an environment where, if you could put your Bugatti in space and still have it operate, if you were in a race with us and the starting gun goes off, you’re going to be out of sight and people will be looking at us like, “Are you moving?” [laughs] But a month later, or a few weeks later, we’re going to pass you because you’ll run out of gas and have to coast. The challenges are equally huge in both of the regimes we operate, but there’s just a totally different scale that I find amusing.
FH: Just like the distances. We’re talking about a 10km straight, which is nothing in space, you’re trying to get from one star system to another [laughs].

LJ: Well maybe someday, right now we’re just trying to get from one planet to another, and that’s hard enough.
FH: Is the solar sail something that could potentially propel a mission to Mars?

LJ: It could. A solar sail with low acceleration is good for lightweight spacecraft because if it’s a heavy spacecraft with low acceleration, you aren’t going to get that high velocity. There’s another project that I think is going to be funded – we find out in December – which will take the sail to the next level. Instead of 86 square metres, it’d be 1,600 square metres, doubling our acceleration. One of these days these sails are going to be square kilometres in size. That’s in 100 years or so, and that will be sending probes to other stars, in my opinion.
FH: And this is because it saves weight? To get it into orbit there is a certain capacity of the rocket, so you need to save weight and it needs to be as light as possible?

LJ: Yes, absolutely. And once we’re flying, mass reduction counts for everything, we try to save grams [laughs].
FH: So do we [laughs].

Bugatti evolution, image courtesy of Bugatti

LJ: I’m surprised, I didn’t know that your tolerances were down to grams.
FH: Yes, every gram counts. Because on Earth, not only do you have to worry about the air density, altitude, humidity, warmth and tarmac temperature, but you also have to consider the weight that pushes onto the tires, and the centrifugal forces they’re exposed to are immense. So every gram counts to make the car as light as possible. For example, we leave the valve caps away because they’re 23 grams. What I was wondering is, let’s say you have the solar sail and the light of the sun hits it, because your vehicle mass is so minimal and there’s no resistance, you keep accelerating. If you do that for years, you’ll be running at close to light speed, so how do you slow down? Do you retract the sail?

LJ: You accelerate as long as the sun is shining, but acceleration drops as you move away from the sun, the inverse square of the distance. So if you double the distance, you’re only getting one fourth the amount of sunlight, therefore only one fourth the amount of pressure. By the time you get to Jupiter, your thrust is down to about four percent of what you had on Earth, so your acceleration will drop as you leave the solar system. In the future – again, we aren’t doing this today – you’ll want to keep that acceleration high, so you might look at taking a high-powered laser and shining it on the sail to keep acceleration high. But you’re right, you’re going to reach your destination and because you’re going so fast you’ll just fly right by. But if you use sunlight to speed up, you can use starlight from the incoming star to slow down, just by changing the angle of the light. There are other techniques that people are exploring and I’ve looked at somewhere you use the magnetic field of the star as a brake.

But again, that’s all in the far future. In the near future, the solar sails are of interest to space scientists because they allow them to access orbits to view the sun and reach destinations that you can’t currently because rockets run out of fuel. Where are we going to go with high-speed cars? I guess one of the questions I have for that industry is, with everybody moving towards electric cars, are you working on land speed records for those?
FH: I think there are guys already trying this, however at the moment we’re observing things but aren’t on that track. Once you reach a certain point and exceed a megawatt, the weight of battery you’d have to carry doesn’t make much sense. So there are no current plans for other propulsion systems. What of the future? Well, certainly there are a couple of things that they need to do, like lightweight construction, that filter down into making products. This is to do with multi-purpose parts, so you have two parts for two purposes, if you can combine these into one part, you save weight. If you look at the newest cars and compare them to how they’ve evolved in the last 50 years, unfortunately they’ve only become heavier. Now they have become much safer and emissions are better, there’s pedestrian protection, entertainment and luxury added plus environmental protection hardware, but the weight hasn’t come down. This will be the biggest challenge in the upcoming decade, to still improve these things, but also lose weight.

My dream would be cars that are really lightweight but run the same, that’d be perfect. There’s also the comparison of cars getting bigger. Let’s take Audi, the biggest car is the A8, and if you take the first generation in the 90s, it’s nearly as big as the A4 today. So cars are becoming bigger until the moment the brand can invent a new car to slot underneath, serving the original size they were offering. This is about product life cycles. Also for Volkswagen, there’s the Golf Mk1 from the 70s, which is the same size as the Up, which is the car that is two classes below the Golf. They’ve actually already done that twice. The reason is to introduce new cars and attract new customers.

From my perspective, that’s the biggest challenge, to incorporate these into production methods. We use the most expensive materials you can buy or develop, but we’re not using these for mass-production, just as NASA won’t mass produce a rocket, it’s a single piece. So this frees you guys up, just as it does us, to go for the most efficient method of solving a particular problem, which you couldn’t do if you were mass-producing.

LJ: I think for us, there’s a couple of things to differentiate. With the rise of these new space companies like SpaceX and the recent rise in the commercial launch industry, the launch has now gone commercial. You mentioned that you have to design and keep within your budget for the market, right? Well for launch, that has now become a market and a commercial enterprise, and that’s freed up NASA and our technology work to advance on our next leg, which is what I work on, the in-space propulsion. So I think there are a lot of parallels in commercial launch with the market pressures you feel, because the companies that do it at the lowest cost sort of mass produce it. For us, it’s huge because it’s bringing down the cost of launch.
FH: That is a super interesting analogy I hadn’t thought about. It’s true, also with the Falcon Heavy rocket [a heavy-lift launcher designed by SpaceX recently selected by NASA to launch a space probe in 2022], that’s going to offer like a shipping service almost, no? Which frees you up to think about the really advanced stuff. There’s a similar analogy here. Let’s say the mass-market cars that Volkswagen is producing put us on the financial basis that we can then invest in finding some really far-out technology and incorporating that into a vehicle that will then trickle back down to the mass-market product.

“Some technologies that we’re pioneering in space might actually become a commercial service one of these days, like launch is becoming. “

LJ: You’re exactly right, that’s how I view it. That’s been the economic philosophy for space exploration for the last ten years. For us, the less we have to pay to launch something, the more money we have to do other things. So these low-cost launches have been great. If you take a long-view, one of these days perhaps there will be asteroid mining industries in space which will be using my solar sail system in a mass-produced, commercial way to do the prospecting. Some technologies that we’re pioneering in space might actually become a commercial service one of these days, like launch is becoming.
FH: Absolutely intriguing.

LJ: I have a final question for you Frank, have you seen the movie Ford v Ferrari?
FH: Of course I have [laughs].

LJ: I haven’t seen it yet but I have the DVD here to watch, do you recommend it?
FH: It’s excellent. All the car stuff is actually filmed with real cars, there’s no CGI in there and you can see that. I think they’ve done a fantastic job on that movie. Les: Good to know, so when I watch it I know that it’s got a real designer’s blessing [both laugh].

Feature originally published in HERO 24.

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