This segment is part of the IEEE Spectrum series “Fastest on Earth.”
The Fastest Car: Bloodhound SSC
TRANSCRIPT:
SusanHassler: What fast thing is as revered as the automobile? Cars are, for most of us, our only connection with what it feels like to be driving something very fast. But a team in England has taken our obsession with fast cars to the extreme—they’re building a car that will go a thousand miles an hour. Lisa Raffensperger traveled to London to take in the car’s first public appearance.
Lisa Raffensperger: They rolled up in Porsches, Jaguars, and Ferraris. Middle-aged men wearing loafers and carrying backpacks piled out of cars. Antique roadsters and pristine Bentleys pulled up onto the grass to park.
Lisa Raffensperger: I, on the other hand, made my grand entrance to the London motorsports festival [London Motorsport Show] in slightly humbler fashion…
Bus driver: “Bus to Goodwood, ladies and gents. Festival of Speed.”
Lisa Raffensperger: …on the free shuttle bus. The Festival of Speed, held outside London every year, is a car lover’s dream.
Festival announcers: “Festival of Speed radio on the way in, in association with The Telegraph, you’ll have heard my colleague Chris Druitt talking to some of the great characters from across the pond.”
Lisa Raffensperger: Vintage Indy 500 cars roared by on the racetrack. Slick Formula One racers stood on pedestals under the summer sun. A crowd began settling into the bleachers. One man poured himself hot tea from a thermos.
Lisa Raffensperger: But the most stunning car on the fairgrounds that day wouldn’t grace the track. It won’t appear in a showroom. Only one man will ever sit behind its wheel. Tucked away in a tent off to the side was a car unlike any that’s ever been built. A car that will go four times as fast as the fastest car you can imagine. A car that will drive faster than the speed of sound.
[race car noise]
Lisa Raffensperger: Just once in history has a car broken the sound barrier. That was in 1997. The car was the Thrust SSC—for supersonic car—a slender black needle flanked by huge jet engines. It was built by a team of British engineers led by Richard Noble, and its driver was Royal Air Force pilot Andy Green. In the Nevada desert, Green piloted the car to a land-speed record: 763 miles per hour, breaking the speed of sound.
[sonic boom]
Lisa Raffensperger: The shockwave knocked frames off the walls of houses dozens of miles away. Now the team is preparing to smash its own record with the Bloodhound SSC. The car has been in the works since 2007. And it’s currently being built in a workshop in Bristol. And when it is raced in the desert of South Africa, the Bloodhound will set a new land-speed record of 1000 miles an hour.
[race car noise]
Lisa Raffensperger: The first thing you notice about the Bloodhound is its size. It’s very, very big. Shaped like a huge dart, it’s 9 feet tall and three times as long as a normal car. But then, not much about the Bloodhound is like a normal car. For starters, there’s the rocket. Engineer Daniel Jubb has designed the world’s most powerful hybrid rocket to propel the car. It’s similar in size to the rocket powering Virgin Galactic’s SpaceShipTwo. And the “hybrid” part comes from its two components, Jubb explains.
Daniel Jubb: We use a solid fuel grain, which is very similar to the propellant in a solid propellant rocket, but it won’t burn on its own. It can only burn in the presence of a liquid oxidizer, which is stored in a separate tank. That gives you the ability to turn off the flow of oxidizer and shut the system down. So it’s the ideal candidate for use in a land-speed record car, because you have that element of controllability while retaining simplicity.
Lisa Raffensperger: The rocket’s built into the bottom of the car. And above it, just behind the cockpit, is the car’s other propellant: a fighter-jet engine.
Daniel Jubb: What we have with Bloodhound is a really quite elegant solution with the jet engine and the rocket. The jet engine is an EJ200, a proven well-established unit, and it’s very controllable. However, the drag from the air intake, and the size of the engine, meant that we wouldn’t get to 1000 miles an hour simply by using two jet engines. So we need the brute force of the rocket.
Lisa Raffensperger: Though previous land-speed record cars have used rockets or jet engines, Bloodhound is the first to use both. And finally, the car relies on one additional engine—from a Formula One racer. But it doesn’t power the car. It’s needed just to pump the liquid oxidizer into the rocket, at a flow rate fast enough to fill a bathtub in three seconds. Putting all those components into one vehicle was the job of chief engineer Mark Chapman, and it came with its fair share of headaches.
Mark Chapman: The problem is, the lower altitude you go, the thicker the air becomes. Now, low aircraft do fly at twice the speed of sound. The Typhoon we got the engine from, it flies at twice the speed of sound. It cannot do that at the altitude we’re driving the car at. In fact, nothing has gone that speed at the altitude we’re going at. So we have to be very careful at how we get the flow into that engine.
Lisa Raffensperger:Wheels also do weird things at such extreme speeds.
Mark Chapman: So the way the car steers is like a conventional car: It’s got double wishbone front suspension. Andy’s only got a couple degrees of steering lock. So he’s got a rubbish turning circle, but he hopefully doesn’t need to park or anything like that. Up to about 400 mph, these work like wheels on your car. They steer by sticking to the ground. And as Andy turns, it digs in and turns the car. Above about 400, they start to work like rudders. More and more, the aerodynamics of the wheel are what’s causing it to do the steering.
Andy Green: There’s a tremendous sense of awe about enormous power and enormous quantities of almost anything. Particularly with vehicles for speed…
Lisa Raffensperger: Bloodhound pilot Andy Green.
Andy Green: …because it is something you can actually observe—it’s very difficult to observe enormous weight, or indeed, enormous power from an engine. But enormous speed you can actually see something moving incredibly quickly and get a sense of what it’s doing.
Lisa Raffensperger: But if you want to feel what it’s like to drive faster than the speed of sound—not just to observe it—here’s the closest I can offer. A video recording takes us back to 1997. Andy Green is settling himself into the cramped cockpit of the Thrust SSC. All you can see out the windshield is desert, with a white line stretching toward the horizon.
Unidentified crew member: SSC is ready to roll.
Lisa Raffensperger: The car responds slowly to the throttle but then starts picking up speed.
Andy Green: By 200 miles an hour, I’ve got full power on, the equivalent of 100 000 horsepower. It’s now accelerating a 10-ton car at over 20 miles an hour per second, so the car is literally going from 200 to 300 in 5 seconds, and to 400 in another 5 seconds, and to 500, and so on.
Lisa Raffensperger: Five hundred, 600. The car is fishtailing. It veers 50 feet from the line you’re driving.
Andy Green: Approaching 700 miles an hour, the airflow starts to go supersonic.
Lisa Raffensperger: You enter the “measured mile,” where you will be timed.
And the mile is over.
Andy Green: The actual measured mile takes 4.7 seconds.
Lisa Raffensperger: Immediately you close the throttle, and all your weight plows forward.
Andy Green: And that’s a huge physical change for me, from being pinned back in my seat to being thrown forward into the harness.
Lisa Raffensperger: When you’ve slowed enough, you apply the brakes.
Andy Green: Then it all starts to happen in slow motion. By the time you get down to 200 miles an hour, it does actually feel so slow you could just get out and walk.
Lisa Raffensperger: And as you come to a stop, just two minutes after setting off, you’re 13 miles from where you started, and you’re the fastest thing that’s ever crossed the earth’s surface. I’m Lisa Raffensperger.
