The Bloodhound Adventure

This is Bloodhound SSC.

It's going to be the fastest car in the world,

and it's designed to travel at over 1,000 miles an hour.

I'm Dr Yan Wong and I'm here in the home of Bloodhound

where scientists and engineers are all working on this amazing project.

And with me are children from around the country

who are investigating what will make this

one of the most incredible vehicles ever to be built.

It's called Bloodhound SSC. SSC stands for supersonic car.

It's trying to travel over 1,000 miles per hour.

That's faster than a bullet fired from a gun.

It's aiming to break the land speed record of 763 miles an hour,

set by this car in 1997.

It's taken five years

of the latest maths, science and engineering to design it.

So you've seen Bloodhound SSC now. What do you make of it?

It's amazing! But is it really a car?

It doesn't look like one.

Or is it a plane?

-Or maybe it's a bit like a boat?

-ALL: What?

Well, that's what I want you to go and find out.

We've come to Mallory Park racing track in Leicestershire.

We want to find out why, if Bloodhound is a car,

it looks so different to other racing cars.

At the track today

is Bloodhound team engineer Conor and racing driver Simon.

Why is this car different to Bloodhound?

This is a distant cousin of Bloodhound.

This was designed to do 200 miles an hour.

Bloodhound, remember, does 1,000 miles an hour.

This car has a piston engine.

Bloodhound has a jet engine and a rocket motor.

This car is designed to go fast down the straights

but quick round the bends, so it's a shorter wheelbase.

Bloodhound, we just focus on going very fast in a straight line,

so a very long wheelbase.

Would you like to see me take this out for a run?

-BOTH: Yeah!

-Let's do it.

So Bloodhound is a bit like a car but looks different

because it only has to go in a straight line

to break the land speed record -

it certainly won't be going around bends like this.

But it doesn't explain why racing cars

seem to come in all shapes and sizes.

Maybe it's something to do with how fast they go.

Which one of these cars is the fastest?

That's the interesting thing.

In a straight line, they're almost exactly the same top speed.

Conor can tell us why that's so important for Bloodhound.

Really great question. If you look at this car,

it's a really streamlined shape and really narrow wheels.

This car's streamlined but it's got big wings on it

to give it downforce and really wide tyres.

This is closer to Bloodhound.

We've got a streamlined shape and we want very narrow wheels, low drag,

because we're trying to be as slippery as we can

to go as fast as we can in a straight line.

We've come to a water ski park in Gloucestershire...

To meet Junior Championship water-skier Katie Nutt.

Katie started skiing when she was just four years old

and is now a national champion for her age.

Travelling at speeds of up to 32 miles an hour,

she certainly knows all about getting across water fast.

But first, we're asking Bloodhound aerodynamics expert Ben Evans

why he thinks Bloodhound is like a boat.

We think that what's going to happen,

even though Bloodhound is running across a solid desert surface,

because it's going to be going so fast,

it will actually be breaking up that surface

and turning it into almost like a liquid,

and it will behave a little bit like a boat.

So the faster it goes, the more it will raise up out of the surface.

What's Bloodhound got to do with waterskiing?

The wheels will be a little bit like Katie's water-skis.

As it gets faster, the car will rise up.

Actually, the shape of Bloodhound is very similar

to the shape of Katie's ski.

It's very long and thin and has a pointy front

and that's to get the drag of the car down as low as we can.

Is that like a rocket being very long and thin?

Absolutely. The reason rockets

are long and thin is the reason why Bloodhound is long and thin.

Bloodhound is a bit like a rocket,

just on its side, skimming across the top of the desert.

OK, so Katie is very low down in the water now she's moving very slowly,

and as the boats speeds up and pulls her,

she raises up out of the water. She's now on top of the water.

I think Bloodhound is going to do something very similar to that.

'Unlike Katie, Bloodhound will have to be in contact

'with the surface at all times

'in order to break the land speed record.'

And you can also see the waves that she's creating.

Bloodhound will also be creating waves,

but they'll be shockwaves in the air, not on the water.

So now her ski is right up on top of the water gliding across the top.

Bloodhound's wheels will have risen up on top of the desert

and be sliding across the top of the desert.

'There's one person who surely knows whether Bloodhound is a plane,

'and that's Bloodhound's driver Andy Green.

'He's also a fighter pilot for the RAF.'

Is Bloodhound a plane?

Bloodhound is very much a car.

The big challenge about any high-speed car

is keeping it on the ground,

and unlike an aeroplane like this, we can't generate any lift,

because, at five times as fast, you'd generate 25 times as much lift

and your car would fly.

We have to keep it on the ground all the time. That's difficult -

that's what's taken us five years of research.

So if you're a pilot, why are you driving Bloodhound?

It's a good question.

Of course, it is a car,

so why have you got a pilot who's used to flying driving the car?

Of course, although it's a car, it's doing supersonic speeds,

so it's doing jet fighter speeds,

it's using a jet engine and a rocket.

It goes five times as fast as a Formula One car.

It's generating huge loads. Things are happening incredibly quickly.

From stationary, the car will be ten miles away in 100 seconds -

much faster than most race cars have to cope with

and much more complicated, so it's very much a perfect background

for me as a Royal Air Force pilot.

That's why we've got a pilot driving the world's fastest car.

-So what do you think Bloodhound is?

-It's shaped a lot like a plane.

I think it's a bit like a boat.

I think it's a bit like a car because it has four wheels.

But it's not really like any of them.

No. And engineers have had to understand

all of those things to design it.

That's when science is most exciting -

when you're doing something that no-one's done before.

It's an engineering adventure.

Bloodhound promises to be

the fastest car in the world but, like all cars,

it needs some way to power it.

So here at New Invention Junior School in the West Midlands,

we are going to build our own cars,

look at different ways of powering them and see which ones go fastest.

-Hiya.

-ALL: Hello.

-Are you ready to build some cars?

-ALL: Yeah.

Excellent, let's go through here.

Just sit down in pairs.

'We're going to explore two different ways of powering the cars.

'One involves using a rubber band tied round the car's axles,

'which will power the wheels. But instead of driving the wheels,

'the second method uses a balloon which will push the car along.'

The cars that you see on the road have engines

which directly power and turn the wheels, which is how they move.

However, some vehicles, like these specialist dragsters,

have no direct power to the wheels,

and instead they are pushed along by rockets or jet engines.

Shall we attach two balloons or one?

We need to attach two because it will make it go faster.

'Of course, you have to try experimenting with this stuff,

'so I'm really quite pleased

'that some of these kids have tried two balloons or extra elastic bands,

'changing the length of axles or straws.'

You've just got to experiment to see what works best.

'It's time to test our models

'and see which methods would work best

'for breaking the 1,000 miles per hour mark.

'But before we reveal the results,

'why don't you go and try out some of these designs for yourself?

'Up first is Bloodhound Heroes

'with a double balloon-powered car.'

Oh, pretty good, just fell off right at the end.

But I reckon that's two and a half seconds.

'Our next two racers, Teddy Bears, with a single balloon-powered car,

'and Jelly Beans,

'the only team to opt for a car powered by elastic bands,

'didn't quite make it to the finish line.'

Oh, a two-balloon car.

OK. No, a bit in front of it. That's it.

Wahey! Nicely done. One and a half seconds.

Right, go.

See? It doesn't work at all.

Oh, 3.85.

So the winner is this Bloodhound 2 balloon-powered car.

You've won the top prize for the land speed record

in New Invention Junior School, West Midlands.

Well done. So what did you think when you were building it?

Well, at first we started with one balloon,

but then we thought, "It's not going very fast,"

-so then we decided to put two on to make it faster.

-Yeah.

And they weren't inflated that huge, were they?

But the two made a big difference,

and the nozzles are pointing out backwards quite well.

We found that if you stuck one to the side and one to the middle

they wouldn't clash, so the air would come out.

Yeah, and the balloons keep out of each other's way as well.

Cos they weren't actually inflating when they were touching.

It rolls rather nicely, it's very smooth.

That must make a big difference.

'On our track, the elastic band car

'didn't have the power it needed to cross the finish line

'and it was the double-balloon cars which proved the most successful.'

So, actually, your model is really like the Bloodhound car,

because in normal cars,

the wheels are powered like those elastic band cars that we made,

but in Bloodhound it's powered by throwing air out the back,

either with a jet engine or a rocket.

This is actually quite similar to the way Bloodhound is propelled.

So Bloodhound is a bit like a boat, a plane and a car,

but that doesn't answer the question of what it's like to drive.

What do you think it would be like sitting in that cockpit

accelerating to 1,000 miles an hour?

-Really exciting.

-Really frightening.

I'm sure it would be both of those but I bet there's a lot more to it

and I'd like you to find out.

This is the man who's going to take his life in his hands

driving Bloodhound.

Andy Green is a fighter pilot in the RAF

and used to fly Phantom jets like these.

We wanted to know what fighter pilot skills

he'll need to drive Bloodhound.

Ah, the lovely countryside of North Yorkshire.

Yeah, and we're here to find out

what it's like to be Bloodhound driver Andy Green.

-Really?

-Yeah, come on, I'll show you.

Left, right, left, right, left, right.

Left, right. Come on, hurry up!

Left, right. Halt. Attention!

Morning, cadets. Today you're going to learn what it's like

to be a fighter pilot

like Wing Commander Andy Green and have a go in our simulator.

-Are you up for that?

-BOTH: Yes, sir.

Jolly good. In that case, if you'd like to follow me?

This is a photograph of the inside of the cockpit

you're going to be sat in.

'Just like Bloodhound,

'there are loads of dials to get your head around.'

Three dials, your airspeed. ADI and the altimeter.

The power dials. Maximum flap for maximum drag.

Left engine, right engine.

I've only shown you about a third of the controls

that you'll have to use to fly this aircraft.

If you were to fly it in real life,

you would need to know what every single one of those dials is doing,

what every single switch and knob does and where it is.

So you're doing an awful lot all at the same time.

BOTH: Yes, sir.

-Did I catch you yawning then?

-HE CHUCKLES

It's a lot to remember.

I think I'm going to struggle if I am going be flying it.

But I hope James will do it cos I'm going to struggle.

You're going to struggle? I'm going to struggle.

The time has come to take the controls and get a sense

of what Andy will have to deal with driving Bloodhound.

Now that's 150.

Now pull back very gently on the stick towards you.

There you go, now you've left the ground. Well done, you're flying.

OK, what do I do now? Do I put the wheels up?

Yes, lift up the lollipop handle on the left.

Well done, that's excellent.

Oh, this is well good.

'It was really difficult controlling the plane at high speed,

'especially when they had to try

'flying between the chimneys of a power station at 900 miles an hour.'

Cos it was in the dark, you were trying to find the right buttons

and it was quite hard. But when I crashed it, I felt really silly.

It felt like you were actually in a plane. It does...

It is a proper simulator.

Bloodhound, with Andy Green in,

it would be a lot faster than this.

It must be amazing going and doing what Andy does.

'So Andy Green's going to have a lot to think about driving the car.

'But what is it really going to feel like?

'We've come to meet the man himself, Bloodhound driver Andy Green,

'to show us his private plane.

'To my amazement, he's offered to take me for a flight

'to demonstrate first-hand what sort of forces he'll feel on his body.'

This is amazing, we're actually airborne!

OK, and here we're coming up to the River Thames.

See the river down on the right with all the boats?

Yeah, I see it. That is amazing.

I never thought I'd see it from this high.

'Flying this loop-the-loop makes you feel

'three times the force of gravity -

'exactly what Andy will feel when he's accelerating in Bloodhound.

'It's time to hold on to my seat.'

That's a flip-back now. There's the ground upside down.

'The force on my body made me feel really heavy

'and I couldn't lift up my hands. Pilots like Andy call this G-force,

'and they feel it when the plane accelerates.'

Going straight down. G's coming on as we accelerate.

And there we are, back straight and level.

I think my veins are popping out of my skin!

Yeah, it does feel a bit weird.

'To think we weren't travelling at speeds anywhere near to Bloodhound.

'No wonder they need Andy's skills as a fighter pilot

'to cope with all the forces he'll experience driving the car.'

He did really, really well. Fantastic, loved all of it.

Natural pilot.

'Wow, that was quite an adventure!

'But Andy told me everyone can get a sense of the forces he'll experience

'back on the ground at the funfair,

'which is why Nikola and I

'have come to meet Bloodhound engineer Annie Berrisford.'

OK, guys, we've come to the fairground today

so we can have a go on that ride. That's going to simulate G-force,

which is exactly what Andy Green will feel on Bloodhound.

-Do you fancy a go?

-BOTH: Yeah!

OK, let's go. Wait for me!

When Andy Green accelerates in Bloodhound,

he'll be thrown back into his seat from G-force

and it will feel just the same as we do on this ride.

It makes simple things like lifting your hands really difficult to do.

just like it was for me in Andy's plane.

This is what Andy Green will be feeling

when he's going really, really fast.

-I thought it would be terrifying.

-Are you loving it?

It still is, but I'm loving it. I'm glad that I went on.

THEY SCREAM AND LAUGH

-How are you feeling? Are you feeling OK?

-I'm feeling great!

The ride felt similar to how I felt in the plane.

It's time to get off - too much excitement for one day!

You felt like you were going to be squashed.

You felt like you were going to vomit but you weren't.

It was holding you there. There was nothing really holding you up.

Bloodhound will be going really fast.

I think Andy Green's going to be feeling like that, but even worse.

So what's it going to be like to drive?

-Very difficult - there's so much to think about.

-Noisy and hard work.

You'd probably pass out because of the amount of G-force.

Yeah, and Andy Green's going to have to concentrate really hard,

not just to watch all the instruments

and to activate the engines, but also to control his body

to make sure that the forces on it don't make him black out.

Wing Commander Andy Green is the man who will be driving Bloodhound

and he'll need to draw on all of his experiences

of travelling at supersonic speeds

if he's going to drive Bloodhound to success.

Fighter pilots like Andy Green need to be able to constantly monitor

loads of stuff that's going on around them

and still react almost immediately to anything that happens.

Oh! When you are going at 1,000 miles an hour in Bloodhound,

that can be a matter of life and death.

Here at New Invention Junior School in the West Midlands

we are going to find out just how hard that can be.

OK, so are you ready to test your reaction times?

What you are going to do is measure it

by something called the ruler drop test.

That involves dropping a ruler

and seeing if you can catch it as quickly as possible.

What I want you to do is hold out your thumb and finger like that.

I'm going to drop this ruler. I'm not going to tell you when,

and you've got to catch it as soon as you see it move.

Shall we try another one?

Oh, that's not too bad. Just there, OK?

Now, was that reasonably easy?

OK and now I'm going to do it and distract you at the same time.

So I've got a sum here and I'd like you to think...

I'll show you it and you have to try and calculate it

whilst doing this at the same time. OK?

So... Ready? OK?

47 - 35 is...? Oh!

HE LAUGHS

-That's hard!

-Pretty hard, isn't it?

Let's see if anyone can even catch the ruler while trying to do a sum.

'Spilt into groups of three, one person to catch the ruler -

'or not, as the case may be - one person to drop it

'and the other to record the results.

'Make sure you repeat each drop three times

'so you can calculate an average.

'Right, let's see how sharp you are!

'Once you've all had a go, introduce the distractions.

'This could be a mathematical sum to work out...'

74 + 26?

100.

'..or a sequence of random letters

'or different shapes and colours to remember.

'Some of them are getting quite good at this,

'so let's try and make it harder and introduce a second distraction.'

Hm, green rectangle and 20.

19.

What seems to be going on here is that the children are getting

better and better at doing it. The things with the distractions

which have happened after practice,

they're getting quite good at. One thing we can do is try

and introduce some really difficult distractions.

OK, right, whenever you fancy.

So you found that pretty difficult, right?

You see how difficult it is when you are being distracted

by loads of different stuff.

And that's just what it's like driving Bloodhound.

There are all these things going on at the same time

that are taking your attention and you still have to be able to react.

Really difficult thing to do.

Whether you're flying a plane or cycling a bike,

there's always a limit to how fast you can go.

The same is true for Bloodhound. But why is that?

Have you any idea why it's so hard to go so fast?

Is it because Bloodhound's really heavy?

Is it because the engine isn't powerful enough?

Those are both good reasons but I think what you really need

to be looking into is what's stopping it, what's holding it back.

And so I'd like you to look into that. OK?

-We've come to Manchester.

-Home of indoor skydiving.

BOTH: Let's go.

Skydivers know what it's like to travel through the air fast,

so maybe they can give us some clues about why it will be difficult

for Bloodhound to travel so fast.

We've come to meet Bloodhound engineer Sarah Covel.

She's in charge of Bloodhound's mission control,

the nerve centre of the land speed record attempt.

I guess you're wondering why we're here at an indoor skydiving centre.

This is Ben. He's an international skydiver

and he's basically going to be simulating how difficult it is

for things like Bloodhound to move through air at high speed.

He's travelling in wind speed of about 150 miles an hour.

If you can imagine, Bloodhound's going to be in a wind speed

of 1,000 miles an hour. So he's going to show us

how difficult it is for Bloodhound to move.

-So what do you reckon, do you want to go and have a go now?

-BOTH: Yeah.

Come on, let's go.

-That's yours.

-Oh, thank you.

It was really difficult for them to keep still

in the hurricane-force wind but Ben knew how to carry Nathan

right to the top.

So, then, boys, how did that feel?

Well good.

Can you imagine that ten times faster?

No. Too fast!

So you can imagine how difficult it's going to be,

you trying to keep your body still in there, how hard it's going

to be for Bloodhound to keep stable and go fast at ten times that speed.

Andy Green's going to have a nightmare.

If we turn the camera on its side,

Ben looks like he's travelling horizontally, just like Bloodhound.

And we can see how important it is to be the right shape.

So what Ben is doing now is he's adjusting his body shape.

So if he keeps streamlined,

he's not got very much of a surface area.

As he moves his body out and moves his arms out,

his surface area increases.

So as his surface area increases, more of the wind hits his body.

That's how he can fly so high up. That's what we have to look at.

With Bloodhound we need to be as streamlined as possible

so we don't create any drag or any lift.

As we can see, Ben's got his body quite tight in.

As he starts to move one side of his body out further,

he creates more lift and more drag on the side of his body,

creating him to spin,

because he's got more force acting on one side of his body.

With Bloodhound we need to try and keep the car completely symmetrical

so that when we're running along at high speed, there's no spin.

Like Bloodhound and the skydivers,

aeroplanes have to be the right shape to push through the air

at high speed, which is why Nathan and James have come

to Manchester's City Airport

to find out how planes manage to keep stable.

Sarah's brought them to meet pilot Mark to show them

his microlight aircraft.

It's a very lightweight plane, a bit like a hang glider,

with an engine attached, which makes it easy to see how planes can fly.

So what's this got to do with Bloodhound?

With Bloodhound, we've got to be really careful

not to generate any downforce or any lift,

and, as Mark's about to show you, the smallest amount of movement

in the wings can create a lot of lift and a lot of downforce.

I'll pass you over to Mark and he'll explain the controls to you.

If we push the bar forwards a tiny little bit,

the first thing that happens is that the nose will pitch up

and then the speed will start to drop off

because we're producing more drag.

We're producing more lift but we're also producing more drag.

If we pull the bar back a tiny little bit, the nose will lower.

We'll start to speed up but we'll also start to descend as well.

And if we move the bar sideways from left to right,

if we pull the left wing down, it will turn to the left.

If we pull the right wing down, it will turn to the right.

You can imagine tiny movements at these speeds,

these slower speeds, make a massive difference.

At 1,000 miles an hour, it's going to make a huge difference.

So we really need to watch our lift and our downforce.

What would happen if Bloodhound did create lift or downforce?

If Bloodhound created downforce,

the wheels are going to be forced in and we'd lose speed.

If we created lift, there's a danger that the car could lift

and flip back over if we created too much lift.

So we need to watch the forces very carefully

and we've got winglets on the side of the car,

like the wing of this microlight,

that adjust constantly to stop that from happening.

OK, let's go!

Now it's James's turn to fly in the microlight

and, amazingly, after reaching just 40 miles an hour,

pushing the bar forward is enough to get airborne.

Woah!

Woo-hoo!

And just tiny movements on the bar is enough to make the microlight

turn sharply through the air. Watch out!

That's cool but it's scary at the same time.

Touchdown!

Bouncy, bouncy.

So once the steering has been taken care of,

and with the power of a fighter jet engine on board,

you'd think Bloodhound would have no problem breaking

the land speed record but it's not as simple as that.

Right, guys, the reason we're down at the pool today is to try

and help us demonstrate how Bloodhound needs to work really hard

to cut through the air.

So, James, I want you to be a fast jet plane

trying to fly along at ground level.

Nathan, I want you to be a jet plane trying to fly along

at high altitude, so 40,000 feet.

When I tell you to I want you to race to the other end of the pool.

So on your marks...get set, go!

Come on, James.

You might not think it but there are similarities between air and water,

but of course water is much denser.

When you move through them, both air and water have to flow past you.

For James, pushing through water

is what it's like for a jet plane at ground level

because the air is so much thicker and it slows you down.

At high altitude, the air is much thinner

and easier to push through so you can travel a lot faster.

Winner! Come on, James. Come on

Come on, James!

You took 12 seconds.

You took 44 seconds.

There's a big difference there, yeah?

So what the pool is showing us is that, actually, air density

at ground level is a lot higher, the air's a lot thicker

and there's more resistance so you've got to work harder.

Nathan, it was a lot easier for you - the air's a lot thinner.

Ultimately it shows us

Bloodhound has to work extremely hard to cut through the air.

So what have you learnt about the problems of travelling really fast?

You've been doing some really cool stuff.

Yeah, we've been indoor skydiving and we've also been in a microlight.

When you're travelling at a high speed,

it's quite hard to push through the air resistance.

Right. And so air resistance is a massive problem with this.

And have you come across anything else?

When we were in the microlight, the man made a little adjustment

and it just swerved and you think you're going to fall out.

But you're not and it's just dead scary.

What's happening here is these little winglets on Bloodhound,

they can be adjusted a tiny amount

and that changes how the air flows over the body.

But it's really difficult to get the engineering right

so that the whole thing stays on the ground.

If you do get it right, you can be a world record breaker.

Fighter jets can travel really fast

but even a fighter jet can't get to 1,000 miles an hour

if it's at ground level,

which is the speed Bloodhound is designed to go at.

That's because at ground level there's much more air

and it becomes really difficult

when you go fast to push all that air out of the way in time.

And here at Links Primary School in South London

we're going to investigate

how Bloodhound is designed to deal with that.

So you probably don't think of air

anything like water over there, do you?

ALL: No.

No, but they are both quite similar, actually.

They both flow around things, they are both fluids.

It's just that air is quite light and water is quite dense,

it's quite hard to push out of the way.

We'll be messing around with water

to show you how to design things that go really fast.

Here, we're going to drop two pieces of modelling clay into water

to show that increasing the power alone isn't enough to travel

through water quickly. I'm going to drop mine

and my volunteer is going to throw hers in as hard as she can.

And everyone else can look and see if they hit...

which one hits first, OK?

And I'll do three, two, and one and then we'll throw, yeah, OK?

Three, two, one. Go!

It's about the same! It's really hard.

If you are going really fast,

things slow down so quickly that basically it makes no difference.

But we're going to show the big difference it makes

if you just change the shape of the Plasticine.

You'll need two large drinks bottles with the tops cut off.

Fill them with equal amounts of water

and then you'll need two pieces of modelling clay,

which must be the same size.

With one piece, mould a flat shape like the one I've just used,

and with the other, experiment making different shapes to see how

quickly they travel through the water.

Make sure you drop them at the same time,

so you can compare the two accurately.

So when you are trying to make things go fast through water,

think of shapes of things that you know go really fast.

OK, so have a go yourselves and see which shapes are the fastest.

Our two best performers are the green ball and the red dart

so let's put them head to head and test them in the big tank

to see which one is the quickest.

Yes! Ooohh!

Did you notice what happened?

As soon as these ones move sideways, they slow down.

So if they go straight all the way through the water they are fine,

but as soon as they turn side on, they are no good!

What do you think we could do about that? Go on.

Put fins on it?

Yeah, you could put something at the end, like a fin,

that makes sure it carries going straight all the way through.

Let's try it with this one.

The fins need to be really thin, though.

Could try something like that, I guess.

Three, two, one...

This action replay clearly shows that the streamline shape

of the red dart with fins for added stability makes it a clear winner.

So this fast shape...

Well, it's a bit like Bloodhound, really, isn't it?

A pointy front and fins at the back

keeps it going straight. That's how to go really fast.

It's one thing going fast, 1,000 miles an hour, but how do you stop?

Anyone, any ideas about how you slow this thing down?

Maybe some brakes?

Maybe a rocket in the other direction?

Those are both good ideas but there's a lot more

to slowing down than you might think, so see what you can discover.

We've come to Santa Pod in Northamptonshire.

-Home of the fastest motor sport on earth.

-Let's go!

We've come to meet Bloodhound engineer Annie Berrisford.

And away from the track we found a car that looks

a bit like Bloodhound - it's long and thin.

So we asked Annie how this car compares to Bloodhound.

OK, guys, so this is the Split Second car.

It's a jet-powered drag car,

so that means it's powered by this jet engine

and it goes in a straight line, just like Bloodhound does.

So Bloodhound also has a jet engine

and is designed to go only in a straight line.

This is Julian, who is the driver,

who's the mad guy sitting in the small cockpit there.

How fast do think this car can go?

Top speed, about 360 miles an hour.

So if it's going that fast, how do you think we slow this car down?

-BOTH: Parachutes.

-Parachutes, that's right.

We've got two parachutes sitting at the back of the car.

Every time, we use one parachute, there's a second parachute.

If that goes wrong, we've got the second just in case.

It's nice to know you're not going to go off the end of the track.

We asked Annie if there are any other types of brakes on the car.

OK, so not only has this car got parachutes at the back

of the car, it's actually got wheel brakes as well on the front

of the car and on the rear wheels.

So why do these have to have brakes?

This has brakes purely to stop it at very low speeds

and to hold it on the start line.

If you were to use these when the car was going as fast as it does,

it would burn out the brakes.

So you need the parachutes for the high-speed running

and wheel brakes for the low-speed running.

-Will Bloodhound have brakes?

-Yeah, Bloodhound also has brakes.

But exactly the same as on this car, we'll use them

to hold the car on the start line

and then also to just slow it down at lower speeds,

so below 100 miles an hour.

Back on the track, it's time to take the car for a run.

Julian uses his wheel brakes to line up on the starting line.

And after a mega fast run reaching just under 230 miles an hour,

it's the parachutes that slow him down, just like Bloodhound will do.

The difference is that Bloodhound will go four times as fast,

which is faster than a bullet fired from a gun.

You don't have to be a grown-up to join in the fun.

Some children as young as eight do this sport.

Meet 13-year-old Paige Wheeler and her little sister Belle.

Paige started the sport when she was just ten

but her eight-year-old sister is officially

the world's youngest dragster racer.

Well, this is my car.

I have a parachute here. Then I have the big tyres.

They're mainly that big so that,

you know, I can get a lot of traction on the track

so I can go faster.

This is my engine.

And then my car's really skinny at the front and big at the back

because it needs to be aerodynamic so it can go faster.

What's it like to drive your car?

When I first put my foot down, my head goes right back into the seat.

It actually really hurts.

How fast do you go?

My top speed is 86 miles per hour,

but we're restricted to 85.

Although her car is a lot smaller than Bloodhound,

Paige has to consider all the same things -

how to accelerate as quickly as possible with her engine

and then how to slow down with her brakes

before running off the end of the track - all in a matter of seconds.

This is what it's like for her

travelling at up to 80 miles an hour.

Imagine what it will be like for Bloodhound's driver,

Andy Green, travelling over 12 times faster at 1,000 miles an hour.

So we know how Bloodhound will slow down

but just how quickly will it slow down?

Back at the racing track, we asked Bloodhound team-mate Conor

to help us find out how quickly brakes can stop a car.

You guys are going to put these boxes where you think is best,

in the middle of the road.

OK, guys, so look over to the side of the track.

The end of those green barriers there, that's where Simon,

our friendly racing driver, is going to start braking.

He's in a family car, the surface is quite grippy.

Nice, grippy tyres, racing driver - he will be good at the brakes.

Have a think. It's your guess how far it will take him to stop.

Don't want to hit the boxes

but we want to get it close. 60 miles an hour.

So that's almost like motorway speed in your mum and dad's cars.

You think? So that's starting from here.

You think that's enough?

Further. 60 miles an hour.

60.

-There.

-There?

-Yeah.

-Do you think we should get out the way, then?

-Yep.

I think we probably should, come this side.

You pretty much chose around the same distance.

You're both putting the boxes down round the same point.

-How far do you think that is? Five metres? Ten metres?

-Um...

Yeah, about nine.

Maybe nine metres?

Seven.

'When racing driver Simon gets to the end of the green barrier,

'he'll slam on the brakes.

'Let's see what happens.'

What do you think, guys?

-Were you expecting that?

-BOTH: No.

-It took longer that you thought.

-Yeah.

And that's with the really grippy tyres with a racing driver

on a really clean grippy circuit.

So, stopping - more of a challenge than you thought, yeah?

-How far off do you think you were?

-About half.

-About half.

Do you think Simon started braking early as well? I think he did.

I think he was worried about hitting the boxes in his car.

Braking, slowing something down,

is a huge challenge and almost as difficult as getting it to go fast.

Really important to do it safely.

So what have you learnt about how Bloodhound is going to slow down?

It's going to need a lot of space to slow down.

The car will be going too fast for normal brakes, so it will overheat.

I think it'll use a parachute.

Yeah, it's also going to use these things on the side here,

which are called air brakes. They pop out and as the air hits them,

it slows down, it creates something called drag

and that's what the parachute does as well.

When the parachutes pop out, the air gets caught in them, causes drag

and that's how this slows down.

It's going to be quite an experience for Andy Green to slow down so fast.

Bloodhound is travelling so fast that brakes alone

aren't enough to stop it,

so it uses a couple of different ways of stopping

and one of those is a parachute.

I'm at Links Primary School

to investigate what makes a good parachute.

-Have any of you made a parachute before?

-No!

If I have a tissue like this and I just drop it... Whoa.

Yeah?

But if I just squish it up like that and then drop it,

what's going to happen?

So why does that happen?

Because in a parachute, it has to be flat

but when you put it in a ball,

no air can push it up, so it goes directly down.

Exactly, so it needs a big, what's called a surface area,

it needs a big area to catch all that air as it comes down

and that's really what makes a good parachute.

So we've got cloths, string, Sellotape, card

and you are going to have to work out how to make your own parachute

and stop an egg from breaking. OK?

Let's get cracking!

Why don't you try making your own parachute?

Think about other materials that you could use.

We've decided to make a hot air balloon design, so it will catch it

and we're going to put the egg in that cup there,

and the cup will sort of be a cushion.

OK, it's time to put some of these designs to the test.

Three, two, one...

Yeah, fine!

Right, I think this ground is too soft.

None of the eggs are breaking, it's just far too easy.

I'm going to have to make this a bit more challenging!

Let's go over here and I'll climb up on the roof!

-Hiya!

-Yeah!

-So shall I try them one by one, yeah?

-Yeah!

OK, ready?

-Arrgh!

-LAUGHTER

Not bad.

Did it survive?

A tiny bit, just a tiny bit.

So who just Sellotaped an egg to a plastic bag?!

Well and truly scrambled!

< Three, two, one!

It survived! It survived, yeah!

-So did you see what happened there?

-Yeah.

-Quite a lot of them broke,

but the best ones were the ones that floated down really slowly,

that caught lots of air and also had some cushioning on the bottom.

So Bloodhound uses a parachute, amongst other things, to slow down.

It's very effective when you catch lots of air.

We're on a mission to find out what's needed to build

the world's fastest car.

Now, just like a normal car, Bloodhound has wheels.

But there's something very different about them. Have you noticed what?

Well, maybe my willing investigators have found something out.

So like any normal car, Bloodhound has four wheels.

But what's different about them? Have you noticed anything?

It doesn't have any tyres.

Yes, it doesn't have any tyres. And there's a very good reason for that.

And what I'd like you to do is find out why.

Unlike a normal car, Bloodhound only has to go in a straight line

to break the land speed record, but surely it still needs tyres?

We've come to Mallory Park racing track in Leicestershire.

And we're going to burn some rubber!

Hundreds of different types of cars use this track every day,

from racing cars to motorbikes.

So where better to try to find out why tyres are normally

so important for driving?

At the track today is Bloodhound team mate Conor

and racing driver Simon.

They've put a swingometer device on top of the car,

so what on earth is that all about?

And more importantly, what's it got to do with Bloodhound?

We're going to go on the track this time with Simon in this car.

We're going to use this arrow to show what's going on with this car

as the tyres grip as we go through the bends.

When we're in the car and feel our bodies being thrown left and right,

we'll chat and try and figure out which way we think the arrow's going

and which way the forces are acting on us in the car

-as it goes round the bends. OK?

-Yep.

We wouldn't be able to drive along like this if we didn't have tyres.

Simon would put his foot on the throttle

and probably the wheels would just spin and spin and spin.

Feel the grip. Feel the tyre gripping,

pushing you right over that side.

Which way did you feel yourselves going?

Left then right.

Get ready for another change, another change. Well done.

When you go into the corner, the car rolls one way.

You change direction and the car rolls the other way.

And if there were no tyres on these wheels,

we'd just slip straight off the track,

because there is very little grip without having the rubber.

-Feel the forces and when we go left, which way does your body go?

-Right.

-And when we go right, which way does your body go?

-Left.

Which way do you think the arrow on the roof went? Same as you?

Same as you. Is that how your mum and dad drive?

-No.

-My dad does. He's a maniac.

But having tyres doesn't always mean your car will stay on the road.

We wanted to know why these cars were spinning even with tyres.

So we asked Bloodhound team-mate Annie Beresford.

OK, guys, what we've got here is cars doing drifting.

So they've got normal road tyres on,

exactly like what you've got on your car that you came in today,

but I bet you weren't driving like this.

Now, your tyres are normally giving you the grip

that you need to stay on the road and drive sensibly round corners.

These guys are actually spinning their wheels so fast

that they're losing that grip and enabling them to slide.

We're really lucky with Bloodhound

in that we're going in a straight line only

so we don't actually have to go round any corners.

Bloodhound's wheels will need to travel so fast,

they'd also lose grip. Tyres would get so hot, they'd explode.

If Bloodhound had tyres, the grip would actually slow the car down.

But not having any tyres comes at a price.

You saw how important tyres are in that car whizzing round the track.

Have a play on these bikes and see how important tyres are on a bike

-and see whether you can spot a difference, OK?

-Yep.

So jump on, go for a ride around, then we'll have a chat.

Ready, guys? Off you go.

There's something very strange about Anton's bike

that's making it very difficult to steer and so bumpy.

How was that?

-Bumpy.

-Slippy?

-Yeah.

Did you feel like you were going to fall off at all? Wobbly?

Yeah, when I was turning back round, I felt like I was going to slip.

We saw your back wheel was all over the place because there's no tyre.

You were fine because you had lovely squashy tyres, nice and grippy.

-Could you do that every day or was that a one-off?

-One-off.

-One-off.

So on the road, on bikes, tyres are a great thing.

But for Bloodhound, we're too fast for tyres.

The fastest tyres in the world, 450 miles an hour, we're going 1,000,

so Bloodhound has solid wheels.

Just like you, we're running on the rims, no tyres.

So we have to design that into the car.

Bloodhound's wheels are also really thin for such a big car

and we wanted to know why.

It's time to get our skates on.

-How did you find that? Was it good?

-Yeah, slippy.

-Slippery.

Really slippy? Why do you think that was so slippy?

Is it because our blades on our shoes are really thin?

Yeah, your blades are really thin

and you're on a really, really slippy surface

and there's very little friction between the two.

Whereas if you were to step onto the Tarmac, it's really grippy

and you wouldn't slide anywhere - like Bloodhound.

We've actually got very thin wheels so we can cut through the ground

very, very easily and there's not a lot of friction on those wheels.

It also means stopping and slowing down is harder for us.

We can't use wheel brakes because the wheels will slide quite easily.

So what have you learnt about Bloodhound's wheels?

The wheels are made out of aluminium and if they were proper tyres,

-at high speed they would explode.

-Right, OK, anything else?

Yes, the Bloodhound car did not have any tyres

because the tyres would grip to the ground and make it go slower.

OK, but if it doesn't have tyres, it must be really bumpy, yeah?

A normal car would have tyres to go round the bend, but the Bloodhound

does not need tyres because it is going in a straight line.

Well, glad I'm not riding it!

Bloodhound is designed to go at 1,000 miles an hour,

and that's going to make it the fastest car in the world.

But although, like a normal car,

it's got wheels, it doesn't have any tyres.

We're here at Links Primary School in South London

to try and find out why that is.

So do you know why a normal car has tyres? Go on, then.

-To grip onto the road?

-Yeah, and that grip is called friction.

Here's a really quick demo to show how powerful friction is.

Interlace the pages of two paperback books

and see if you can pull them apart.

Arrgghh. It's pretty strong.

All that's holding those together is the friction between the pages.

The harder you pull, the more they push together

and the more friction there is.

Do you want to have a go?

But Bloodhound isn't using the tyres to power it,

it's using a jet engine and a rocket,

and so it doesn't need to grip the road like that.

And, besides, it's not even going round corners,

so it doesn't need the tyres to grip when going around corners.

Even if it did have tyres, the tyres might be in a bit of trouble.

I'll show you why, but it's going to get messy!

For this bit, all you're going to need is a turntable,

or something similar that spins round, and some jelly.

We'll put that in the middle, yeah?

Eww, it looks like bogey!

Do you want to try spinning it?

Bit faster.

-Can you see what's happening to it?

-I think...

-So did you see what was happening there to the jelly?

-Yeah.

-So what was happening?

-It was spreading around

and then the force was taking it in different directions.

Absolutely, the forces on it were just throwing it in all directions.

-It just went splurrtt, didn't it?

-It's like an explosion.

That's what would happen to tyres if they went that fast on Bloodhound.

If you're doing this at home

or if you don't have a turntable, try raiding the kitchen cupboards

and see if you can find a salad spinner.

Right, let's spin it up!

-Let's take the lid off!

-Where's it all gone?!

That really has disintegrated.

-Look, it's all coming out of the bottom as well!

-Ugh!

So this is what would happen to car tyres going at that sort of speed.

They would just completely disintegrate! Look at that!

All cars need an engine,

but where do you get one that gets you to 1,000 miles an hour?

Well, that's the challenge for our team of investigators to find out.

So it's a big car.

Have you spotted anything that would propel it forward?

-It seems to have two enormous exhausts.

-Well spotted.

What do you think is going to go in there, and in there?

That's for you to find out.

We're here at a secret rocket testing centre in Buckinghamshire.

Shhhh, this way.

Hello there. Welcome to the Bloodhound rocket test site.

My name's Daniel Jubb. I'm the rocket scientist on Bloodhound SSC.

-Would you like to find out more about how rockets work?

-Yes!

Excellent, let's go and do some experiments.

So what has tug-of-war got to do with rockets and Bloodhound?

To understand how rockets work and what makes Bloodhound move,

you have to understand about forces.

You're both exerting a force on this rope, but it's not moving,

so the forces are balanced. But if you introduce a larger force,

like the thrust from a rocket or a jet engine,

we can start things moving.

Stop!

But to accelerate to 1,000 miles an hour,

Bloodhound is going to need a huge force to push it along.

Although it will have a fighter jet engine, that won't be enough.

It's going to need a rocket.

This is the kind of rocket you may be familiar with - a firework.

It works on the same principle we're going to use

to propel Bloodhound across the desert at 1,000 miles an hour.

We have gunpowder inside this rocket.

Now, that's a mixture of a fuel and an oxidizer in solid form.

When we ignite that, it generates a huge volume of hot gas.

We expand those hot gasses through a nozzle

and accelerate them rearward at very high speed.

That produces a force - thrust -

acting on the rocket to propel it forwards.

-Wow!

-That's amazing!

So to generate that enormous volume of hot gas in a rocket,

you need to burn a fuel.

Daniel showed us just how powerful some solid fuels can be.

The secret is they contain their own oxygen,

which everything needs to burn well.

But Bloodhound's going to need

something more advanced than a fireworks rocket.

Cool!

Instead, it's going to use a mixture of solid fuel

and this special liquid called HTP, high-test peroxide,

which is so reactive, it instantly burns the fuel.

It doesn't even need a match to light it.

This really is rocket science!!

Now, in Bloodhound,

we're using a very large quantity of high-test peroxide

to burn a rubber fuel in our hybrid rocket.

Should have brought some marshmallows!

So what's this contraption?

This is the six-inch hybrid rocket

that we've been developing for Bloodhound.

It's not the full-size one that's going to go on the car.

The full-size one will be three times the diameter and twice as long,

but it will actually produce about ten times as much thrust.

In this combustion chamber, we've got our solid fuel

and in this big tank behind us, we've got our hydrogen peroxide, HTP.

Which way will the car move?

The car moves forwards and the rocket exhaust is firing out the door.

So the gasses are being pushed in that direction

and that's exerting a force in this direction against the stand.

Would you like to see the control room

-and watch a video of the rocket firing?

-Yes!

-Let's go!

Five...four...three...two...one...

ignition.

Wow! I wouldn't like to have that

going off in the back of my mum and dad's car!

So what have you learnt about how Bloodhound's going to go forwards?

Bloodhound needs a huge rocket to propel it forwards.

Yeah, that's right! In fact, it's got two engines.

It's got a jet engine here

and that's going to take it to 300 miles an hour

and then they're going to fire off the rocket down here

which will take it to the full 1,000.

-What do you think it's going to be like when that goes off?

-Very noisy.

-Very noisy.

-Scary.

-Yeah.

But it'll only last for ten seconds,

because once they've reached the land speed record,

the rocket's going to cut out and it'll be time to slow down again.

Subtitles by Red Bee Media Ltd