0:00:09 > 0:00:12This is Bloodhound SSC.
0:00:12 > 0:00:15It's going to be the fastest car in the world,
0:00:15 > 0:00:18and it's designed to travel at over 1,000 miles an hour.
0:00:18 > 0:00:21I'm Dr Yan Wong and I'm here in the home of Bloodhound
0:00:21 > 0:00:25where scientists and engineers are all working on this amazing project.
0:00:25 > 0:00:28And with me are children from around the country
0:00:28 > 0:00:30who are investigating what will make this
0:00:30 > 0:00:33one of the most incredible vehicles ever to be built.
0:00:37 > 0:00:42It's called Bloodhound SSC. SSC stands for supersonic car.
0:00:46 > 0:00:49It's trying to travel over 1,000 miles per hour.
0:00:49 > 0:00:52That's faster than a bullet fired from a gun.
0:00:54 > 0:00:59It's aiming to break the land speed record of 763 miles an hour,
0:00:59 > 0:01:02set by this car in 1997.
0:01:02 > 0:01:04It's taken five years
0:01:04 > 0:01:08of the latest maths, science and engineering to design it.
0:01:10 > 0:01:13So you've seen Bloodhound SSC now. What do you make of it?
0:01:13 > 0:01:16It's amazing! But is it really a car?
0:01:16 > 0:01:18It doesn't look like one.
0:01:18 > 0:01:20Or is it a plane?
0:01:20 > 0:01:23- Or maybe it's a bit like a boat? - ALL: What?
0:01:23 > 0:01:26Well, that's what I want you to go and find out.
0:01:31 > 0:01:35We've come to Mallory Park racing track in Leicestershire.
0:01:35 > 0:01:38We want to find out why, if Bloodhound is a car,
0:01:38 > 0:01:40it looks so different to other racing cars.
0:01:40 > 0:01:42At the track today
0:01:42 > 0:01:46is Bloodhound team engineer Conor and racing driver Simon.
0:01:46 > 0:01:49Why is this car different to Bloodhound?
0:01:49 > 0:01:51This is a distant cousin of Bloodhound.
0:01:51 > 0:01:53This was designed to do 200 miles an hour.
0:01:53 > 0:01:56Bloodhound, remember, does 1,000 miles an hour.
0:01:56 > 0:01:58This car has a piston engine.
0:01:58 > 0:02:01Bloodhound has a jet engine and a rocket motor.
0:02:01 > 0:02:04This car is designed to go fast down the straights
0:02:04 > 0:02:07but quick round the bends, so it's a shorter wheelbase.
0:02:07 > 0:02:10Bloodhound, we just focus on going very fast in a straight line,
0:02:10 > 0:02:11so a very long wheelbase.
0:02:11 > 0:02:14Would you like to see me take this out for a run?
0:02:14 > 0:02:16- BOTH: Yeah! - Let's do it.
0:02:19 > 0:02:23So Bloodhound is a bit like a car but looks different
0:02:23 > 0:02:25because it only has to go in a straight line
0:02:25 > 0:02:26to break the land speed record -
0:02:26 > 0:02:30it certainly won't be going around bends like this.
0:02:35 > 0:02:38But it doesn't explain why racing cars
0:02:38 > 0:02:40seem to come in all shapes and sizes.
0:02:40 > 0:02:43Maybe it's something to do with how fast they go.
0:02:43 > 0:02:45Which one of these cars is the fastest?
0:02:45 > 0:02:47That's the interesting thing.
0:02:47 > 0:02:50In a straight line, they're almost exactly the same top speed.
0:02:50 > 0:02:53Conor can tell us why that's so important for Bloodhound.
0:02:53 > 0:02:56Really great question. If you look at this car,
0:02:56 > 0:02:59it's a really streamlined shape and really narrow wheels.
0:02:59 > 0:03:02This car's streamlined but it's got big wings on it
0:03:02 > 0:03:05to give it downforce and really wide tyres.
0:03:05 > 0:03:06This is closer to Bloodhound.
0:03:06 > 0:03:10We've got a streamlined shape and we want very narrow wheels, low drag,
0:03:10 > 0:03:13because we're trying to be as slippery as we can
0:03:13 > 0:03:15to go as fast as we can in a straight line.
0:03:20 > 0:03:22We've come to a water ski park in Gloucestershire...
0:03:22 > 0:03:26To meet Junior Championship water-skier Katie Nutt.
0:03:31 > 0:03:34Katie started skiing when she was just four years old
0:03:34 > 0:03:37and is now a national champion for her age.
0:03:37 > 0:03:40Travelling at speeds of up to 32 miles an hour,
0:03:40 > 0:03:43she certainly knows all about getting across water fast.
0:03:46 > 0:03:50But first, we're asking Bloodhound aerodynamics expert Ben Evans
0:03:50 > 0:03:53why he thinks Bloodhound is like a boat.
0:03:53 > 0:03:55We think that what's going to happen,
0:03:55 > 0:03:59even though Bloodhound is running across a solid desert surface,
0:03:59 > 0:04:01because it's going to be going so fast,
0:04:01 > 0:04:04it will actually be breaking up that surface
0:04:04 > 0:04:06and turning it into almost like a liquid,
0:04:06 > 0:04:08and it will behave a little bit like a boat.
0:04:08 > 0:04:12So the faster it goes, the more it will raise up out of the surface.
0:04:12 > 0:04:15What's Bloodhound got to do with waterskiing?
0:04:15 > 0:04:18The wheels will be a little bit like Katie's water-skis.
0:04:18 > 0:04:20As it gets faster, the car will rise up.
0:04:20 > 0:04:24Actually, the shape of Bloodhound is very similar
0:04:24 > 0:04:26to the shape of Katie's ski.
0:04:26 > 0:04:29It's very long and thin and has a pointy front
0:04:29 > 0:04:33and that's to get the drag of the car down as low as we can.
0:04:33 > 0:04:36Is that like a rocket being very long and thin?
0:04:36 > 0:04:37Absolutely. The reason rockets
0:04:37 > 0:04:41are long and thin is the reason why Bloodhound is long and thin.
0:04:41 > 0:04:42Bloodhound is a bit like a rocket,
0:04:42 > 0:04:45just on its side, skimming across the top of the desert.
0:04:45 > 0:04:49OK, so Katie is very low down in the water now she's moving very slowly,
0:04:49 > 0:04:51and as the boats speeds up and pulls her,
0:04:51 > 0:04:55she raises up out of the water. She's now on top of the water.
0:04:55 > 0:04:58I think Bloodhound is going to do something very similar to that.
0:04:58 > 0:05:02'Unlike Katie, Bloodhound will have to be in contact
0:05:02 > 0:05:04'with the surface at all times
0:05:04 > 0:05:06'in order to break the land speed record.'
0:05:06 > 0:05:08And you can also see the waves that she's creating.
0:05:08 > 0:05:11Bloodhound will also be creating waves,
0:05:11 > 0:05:14but they'll be shockwaves in the air, not on the water.
0:05:14 > 0:05:18So now her ski is right up on top of the water gliding across the top.
0:05:18 > 0:05:21Bloodhound's wheels will have risen up on top of the desert
0:05:21 > 0:05:24and be sliding across the top of the desert.
0:05:34 > 0:05:38'There's one person who surely knows whether Bloodhound is a plane,
0:05:38 > 0:05:41'and that's Bloodhound's driver Andy Green.
0:05:41 > 0:05:43'He's also a fighter pilot for the RAF.'
0:05:43 > 0:05:45Is Bloodhound a plane?
0:05:45 > 0:05:47Bloodhound is very much a car.
0:05:47 > 0:05:50The big challenge about any high-speed car
0:05:50 > 0:05:52is keeping it on the ground,
0:05:52 > 0:05:55and unlike an aeroplane like this, we can't generate any lift,
0:05:55 > 0:05:59because, at five times as fast, you'd generate 25 times as much lift
0:05:59 > 0:06:00and your car would fly.
0:06:00 > 0:06:03We have to keep it on the ground all the time. That's difficult -
0:06:03 > 0:06:06that's what's taken us five years of research.
0:06:06 > 0:06:09So if you're a pilot, why are you driving Bloodhound?
0:06:09 > 0:06:10It's a good question.
0:06:10 > 0:06:11Of course, it is a car,
0:06:11 > 0:06:14so why have you got a pilot who's used to flying driving the car?
0:06:14 > 0:06:17Of course, although it's a car, it's doing supersonic speeds,
0:06:17 > 0:06:19so it's doing jet fighter speeds,
0:06:19 > 0:06:21it's using a jet engine and a rocket.
0:06:21 > 0:06:23It goes five times as fast as a Formula One car.
0:06:23 > 0:06:27It's generating huge loads. Things are happening incredibly quickly.
0:06:27 > 0:06:30From stationary, the car will be ten miles away in 100 seconds -
0:06:30 > 0:06:33much faster than most race cars have to cope with
0:06:33 > 0:06:36and much more complicated, so it's very much a perfect background
0:06:36 > 0:06:38for me as a Royal Air Force pilot.
0:06:38 > 0:06:41That's why we've got a pilot driving the world's fastest car.
0:06:44 > 0:06:48- So what do you think Bloodhound is? - It's shaped a lot like a plane.
0:06:48 > 0:06:50I think it's a bit like a boat.
0:06:50 > 0:06:53I think it's a bit like a car because it has four wheels.
0:06:53 > 0:06:55But it's not really like any of them.
0:06:55 > 0:06:58No. And engineers have had to understand
0:06:58 > 0:06:59all of those things to design it.
0:06:59 > 0:07:01That's when science is most exciting -
0:07:01 > 0:07:04when you're doing something that no-one's done before.
0:07:04 > 0:07:06It's an engineering adventure.
0:07:21 > 0:07:23Bloodhound promises to be
0:07:23 > 0:07:26the fastest car in the world but, like all cars,
0:07:26 > 0:07:28it needs some way to power it.
0:07:28 > 0:07:31So here at New Invention Junior School in the West Midlands,
0:07:31 > 0:07:33we are going to build our own cars,
0:07:33 > 0:07:37look at different ways of powering them and see which ones go fastest.
0:07:37 > 0:07:38- Hiya. - ALL: Hello.
0:07:38 > 0:07:40- Are you ready to build some cars? - ALL: Yeah.
0:07:40 > 0:07:42Excellent, let's go through here.
0:07:42 > 0:07:44Just sit down in pairs.
0:07:44 > 0:07:48'We're going to explore two different ways of powering the cars.
0:07:48 > 0:07:51'One involves using a rubber band tied round the car's axles,
0:07:51 > 0:07:55'which will power the wheels. But instead of driving the wheels,
0:07:55 > 0:07:58'the second method uses a balloon which will push the car along.'
0:08:00 > 0:08:03The cars that you see on the road have engines
0:08:03 > 0:08:07which directly power and turn the wheels, which is how they move.
0:08:07 > 0:08:10However, some vehicles, like these specialist dragsters,
0:08:10 > 0:08:12have no direct power to the wheels,
0:08:12 > 0:08:15and instead they are pushed along by rockets or jet engines.
0:08:23 > 0:08:25Shall we attach two balloons or one?
0:08:25 > 0:08:29We need to attach two because it will make it go faster.
0:08:29 > 0:08:32'Of course, you have to try experimenting with this stuff,
0:08:32 > 0:08:34'so I'm really quite pleased
0:08:34 > 0:08:37'that some of these kids have tried two balloons or extra elastic bands,
0:08:37 > 0:08:40'changing the length of axles or straws.'
0:08:40 > 0:08:43You've just got to experiment to see what works best.
0:08:43 > 0:08:45'It's time to test our models
0:08:45 > 0:08:47'and see which methods would work best
0:08:47 > 0:08:50'for breaking the 1,000 miles per hour mark.
0:08:50 > 0:08:52'But before we reveal the results,
0:08:52 > 0:08:56'why don't you go and try out some of these designs for yourself?
0:08:56 > 0:08:58'Up first is Bloodhound Heroes
0:08:58 > 0:09:01'with a double balloon-powered car.'
0:09:04 > 0:09:07Oh, pretty good, just fell off right at the end.
0:09:07 > 0:09:09But I reckon that's two and a half seconds.
0:09:12 > 0:09:16'Our next two racers, Teddy Bears, with a single balloon-powered car,
0:09:16 > 0:09:18'and Jelly Beans,
0:09:18 > 0:09:21'the only team to opt for a car powered by elastic bands,
0:09:21 > 0:09:23'didn't quite make it to the finish line.'
0:09:23 > 0:09:25Oh, a two-balloon car.
0:09:29 > 0:09:32OK. No, a bit in front of it. That's it.
0:09:34 > 0:09:37Wahey! Nicely done. One and a half seconds.
0:09:41 > 0:09:43Right, go.
0:09:43 > 0:09:44See? It doesn't work at all.
0:09:46 > 0:09:48Oh, 3.85.
0:09:48 > 0:09:52So the winner is this Bloodhound 2 balloon-powered car.
0:09:52 > 0:09:54You've won the top prize for the land speed record
0:09:54 > 0:09:57in New Invention Junior School, West Midlands.
0:09:57 > 0:10:00Well done. So what did you think when you were building it?
0:10:00 > 0:10:03Well, at first we started with one balloon,
0:10:03 > 0:10:05but then we thought, "It's not going very fast,"
0:10:05 > 0:10:08- so then we decided to put two on to make it faster.- Yeah.
0:10:08 > 0:10:11And they weren't inflated that huge, were they?
0:10:11 > 0:10:13But the two made a big difference,
0:10:13 > 0:10:16and the nozzles are pointing out backwards quite well.
0:10:16 > 0:10:19We found that if you stuck one to the side and one to the middle
0:10:19 > 0:10:22they wouldn't clash, so the air would come out.
0:10:22 > 0:10:25Yeah, and the balloons keep out of each other's way as well.
0:10:25 > 0:10:29Cos they weren't actually inflating when they were touching.
0:10:29 > 0:10:31It rolls rather nicely, it's very smooth.
0:10:31 > 0:10:33That must make a big difference.
0:10:33 > 0:10:35'On our track, the elastic band car
0:10:35 > 0:10:38'didn't have the power it needed to cross the finish line
0:10:38 > 0:10:43'and it was the double-balloon cars which proved the most successful.'
0:10:44 > 0:10:47So, actually, your model is really like the Bloodhound car,
0:10:47 > 0:10:48because in normal cars,
0:10:48 > 0:10:51the wheels are powered like those elastic band cars that we made,
0:10:51 > 0:10:55but in Bloodhound it's powered by throwing air out the back,
0:10:55 > 0:10:56either with a jet engine or a rocket.
0:10:56 > 0:11:00This is actually quite similar to the way Bloodhound is propelled.
0:11:10 > 0:11:13So Bloodhound is a bit like a boat, a plane and a car,
0:11:13 > 0:11:16but that doesn't answer the question of what it's like to drive.
0:11:16 > 0:11:19What do you think it would be like sitting in that cockpit
0:11:19 > 0:11:21accelerating to 1,000 miles an hour?
0:11:21 > 0:11:24- Really exciting.- Really frightening.
0:11:24 > 0:11:28I'm sure it would be both of those but I bet there's a lot more to it
0:11:28 > 0:11:30and I'd like you to find out.
0:11:36 > 0:11:39This is the man who's going to take his life in his hands
0:11:39 > 0:11:41driving Bloodhound.
0:11:41 > 0:11:44Andy Green is a fighter pilot in the RAF
0:11:44 > 0:11:47and used to fly Phantom jets like these.
0:11:47 > 0:11:49We wanted to know what fighter pilot skills
0:11:49 > 0:11:50he'll need to drive Bloodhound.
0:11:50 > 0:11:54Ah, the lovely countryside of North Yorkshire.
0:11:54 > 0:11:56Yeah, and we're here to find out
0:11:56 > 0:12:00what it's like to be Bloodhound driver Andy Green.
0:12:00 > 0:12:03- Really?- Yeah, come on, I'll show you.
0:12:04 > 0:12:07Left, right, left, right, left, right.
0:12:07 > 0:12:09Left, right. Come on, hurry up!
0:12:09 > 0:12:12Left, right. Halt. Attention!
0:12:12 > 0:12:15Morning, cadets. Today you're going to learn what it's like
0:12:15 > 0:12:17to be a fighter pilot
0:12:17 > 0:12:20like Wing Commander Andy Green and have a go in our simulator.
0:12:20 > 0:12:23- Are you up for that? - BOTH: Yes, sir.
0:12:23 > 0:12:26Jolly good. In that case, if you'd like to follow me?
0:12:26 > 0:12:29This is a photograph of the inside of the cockpit
0:12:29 > 0:12:31you're going to be sat in.
0:12:31 > 0:12:32'Just like Bloodhound,
0:12:32 > 0:12:35'there are loads of dials to get your head around.'
0:12:35 > 0:12:39Three dials, your airspeed. ADI and the altimeter.
0:12:39 > 0:12:42The power dials. Maximum flap for maximum drag.
0:12:42 > 0:12:44Left engine, right engine.
0:12:44 > 0:12:47I've only shown you about a third of the controls
0:12:47 > 0:12:49that you'll have to use to fly this aircraft.
0:12:49 > 0:12:51If you were to fly it in real life,
0:12:51 > 0:12:55you would need to know what every single one of those dials is doing,
0:12:55 > 0:12:58what every single switch and knob does and where it is.
0:12:58 > 0:13:01So you're doing an awful lot all at the same time.
0:13:01 > 0:13:04BOTH: Yes, sir.
0:13:04 > 0:13:06- Did I catch you yawning then? - HE CHUCKLES
0:13:06 > 0:13:08It's a lot to remember.
0:13:10 > 0:13:16I think I'm going to struggle if I am going be flying it.
0:13:16 > 0:13:20But I hope James will do it cos I'm going to struggle.
0:13:20 > 0:13:23You're going to struggle? I'm going to struggle.
0:13:23 > 0:13:27The time has come to take the controls and get a sense
0:13:27 > 0:13:31of what Andy will have to deal with driving Bloodhound.
0:13:32 > 0:13:33Now that's 150.
0:13:33 > 0:13:36Now pull back very gently on the stick towards you.
0:13:36 > 0:13:40There you go, now you've left the ground. Well done, you're flying.
0:13:40 > 0:13:43OK, what do I do now? Do I put the wheels up?
0:13:43 > 0:13:45Yes, lift up the lollipop handle on the left.
0:13:45 > 0:13:47Well done, that's excellent.
0:13:47 > 0:13:49Oh, this is well good.
0:13:51 > 0:13:55'It was really difficult controlling the plane at high speed,
0:13:55 > 0:13:58'especially when they had to try
0:13:58 > 0:14:02'flying between the chimneys of a power station at 900 miles an hour.'
0:14:04 > 0:14:08Cos it was in the dark, you were trying to find the right buttons
0:14:08 > 0:14:14and it was quite hard. But when I crashed it, I felt really silly.
0:14:14 > 0:14:17It felt like you were actually in a plane. It does...
0:14:17 > 0:14:20It is a proper simulator.
0:14:20 > 0:14:23Bloodhound, with Andy Green in,
0:14:23 > 0:14:25it would be a lot faster than this.
0:14:25 > 0:14:30It must be amazing going and doing what Andy does.
0:14:32 > 0:14:35'So Andy Green's going to have a lot to think about driving the car.
0:14:35 > 0:14:39'But what is it really going to feel like?
0:14:39 > 0:14:43'We've come to meet the man himself, Bloodhound driver Andy Green,
0:14:43 > 0:14:45'to show us his private plane.
0:14:45 > 0:14:47'To my amazement, he's offered to take me for a flight
0:14:47 > 0:14:51'to demonstrate first-hand what sort of forces he'll feel on his body.'
0:14:51 > 0:14:55This is amazing, we're actually airborne!
0:15:01 > 0:15:03OK, and here we're coming up to the River Thames.
0:15:03 > 0:15:06See the river down on the right with all the boats?
0:15:06 > 0:15:08Yeah, I see it. That is amazing.
0:15:08 > 0:15:10I never thought I'd see it from this high.
0:15:10 > 0:15:12'Flying this loop-the-loop makes you feel
0:15:12 > 0:15:15'three times the force of gravity -
0:15:15 > 0:15:19'exactly what Andy will feel when he's accelerating in Bloodhound.
0:15:19 > 0:15:22'It's time to hold on to my seat.'
0:15:24 > 0:15:28That's a flip-back now. There's the ground upside down.
0:15:28 > 0:15:30'The force on my body made me feel really heavy
0:15:30 > 0:15:34'and I couldn't lift up my hands. Pilots like Andy call this G-force,
0:15:34 > 0:15:37'and they feel it when the plane accelerates.'
0:15:37 > 0:15:40Going straight down. G's coming on as we accelerate.
0:15:41 > 0:15:45And there we are, back straight and level.
0:15:45 > 0:15:48I think my veins are popping out of my skin!
0:15:48 > 0:15:51Yeah, it does feel a bit weird.
0:15:52 > 0:15:55'To think we weren't travelling at speeds anywhere near to Bloodhound.
0:15:55 > 0:15:59'No wonder they need Andy's skills as a fighter pilot
0:15:59 > 0:16:03'to cope with all the forces he'll experience driving the car.'
0:16:05 > 0:16:08He did really, really well. Fantastic, loved all of it.
0:16:08 > 0:16:09Natural pilot.
0:16:13 > 0:16:15'Wow, that was quite an adventure!
0:16:15 > 0:16:19'But Andy told me everyone can get a sense of the forces he'll experience
0:16:19 > 0:16:21'back on the ground at the funfair,
0:16:21 > 0:16:22'which is why Nikola and I
0:16:22 > 0:16:26'have come to meet Bloodhound engineer Annie Berrisford.'
0:16:26 > 0:16:29OK, guys, we've come to the fairground today
0:16:29 > 0:16:32so we can have a go on that ride. That's going to simulate G-force,
0:16:32 > 0:16:35which is exactly what Andy Green will feel on Bloodhound.
0:16:35 > 0:16:37- Do you fancy a go? - BOTH: Yeah!
0:16:37 > 0:16:40OK, let's go. Wait for me!
0:16:42 > 0:16:44When Andy Green accelerates in Bloodhound,
0:16:44 > 0:16:46he'll be thrown back into his seat from G-force
0:16:46 > 0:16:49and it will feel just the same as we do on this ride.
0:16:49 > 0:16:53It makes simple things like lifting your hands really difficult to do.
0:16:53 > 0:16:56just like it was for me in Andy's plane.
0:16:57 > 0:17:00This is what Andy Green will be feeling
0:17:00 > 0:17:03when he's going really, really fast.
0:17:03 > 0:17:05- I thought it would be terrifying. - Are you loving it?
0:17:05 > 0:17:08It still is, but I'm loving it. I'm glad that I went on.
0:17:08 > 0:17:12THEY SCREAM AND LAUGH
0:17:12 > 0:17:15- How are you feeling? Are you feeling OK?- I'm feeling great!
0:17:17 > 0:17:21The ride felt similar to how I felt in the plane.
0:17:21 > 0:17:25It's time to get off - too much excitement for one day!
0:17:25 > 0:17:27You felt like you were going to be squashed.
0:17:27 > 0:17:30You felt like you were going to vomit but you weren't.
0:17:30 > 0:17:33It was holding you there. There was nothing really holding you up.
0:17:33 > 0:17:35Bloodhound will be going really fast.
0:17:35 > 0:17:38I think Andy Green's going to be feeling like that, but even worse.
0:17:38 > 0:17:41So what's it going to be like to drive?
0:17:41 > 0:17:45- Very difficult - there's so much to think about.- Noisy and hard work.
0:17:45 > 0:17:48You'd probably pass out because of the amount of G-force.
0:17:48 > 0:17:52Yeah, and Andy Green's going to have to concentrate really hard,
0:17:52 > 0:17:54not just to watch all the instruments
0:17:54 > 0:17:56and to activate the engines, but also to control his body
0:17:56 > 0:17:59to make sure that the forces on it don't make him black out.
0:18:14 > 0:18:18Wing Commander Andy Green is the man who will be driving Bloodhound
0:18:18 > 0:18:21and he'll need to draw on all of his experiences
0:18:21 > 0:18:23of travelling at supersonic speeds
0:18:23 > 0:18:25if he's going to drive Bloodhound to success.
0:18:25 > 0:18:29Fighter pilots like Andy Green need to be able to constantly monitor
0:18:29 > 0:18:31loads of stuff that's going on around them
0:18:31 > 0:18:35and still react almost immediately to anything that happens.
0:18:35 > 0:18:38Oh! When you are going at 1,000 miles an hour in Bloodhound,
0:18:38 > 0:18:41that can be a matter of life and death.
0:18:41 > 0:18:44Here at New Invention Junior School in the West Midlands
0:18:44 > 0:18:46we are going to find out just how hard that can be.
0:18:46 > 0:18:49OK, so are you ready to test your reaction times?
0:18:49 > 0:18:51What you are going to do is measure it
0:18:51 > 0:18:53by something called the ruler drop test.
0:18:53 > 0:18:55That involves dropping a ruler
0:18:55 > 0:18:57and seeing if you can catch it as quickly as possible.
0:18:57 > 0:19:00What I want you to do is hold out your thumb and finger like that.
0:19:00 > 0:19:03I'm going to drop this ruler. I'm not going to tell you when,
0:19:03 > 0:19:06and you've got to catch it as soon as you see it move.
0:19:07 > 0:19:09Shall we try another one?
0:19:11 > 0:19:13Oh, that's not too bad. Just there, OK?
0:19:13 > 0:19:16Now, was that reasonably easy?
0:19:16 > 0:19:20OK and now I'm going to do it and distract you at the same time.
0:19:20 > 0:19:22So I've got a sum here and I'd like you to think...
0:19:22 > 0:19:25I'll show you it and you have to try and calculate it
0:19:25 > 0:19:28whilst doing this at the same time. OK?
0:19:28 > 0:19:30So... Ready? OK?
0:19:30 > 0:19:3447 - 35 is...? Oh!
0:19:34 > 0:19:36HE LAUGHS
0:19:36 > 0:19:38- That's hard!- Pretty hard, isn't it?
0:19:38 > 0:19:42Let's see if anyone can even catch the ruler while trying to do a sum.
0:19:44 > 0:19:48'Spilt into groups of three, one person to catch the ruler -
0:19:48 > 0:19:51'or not, as the case may be - one person to drop it
0:19:51 > 0:19:53'and the other to record the results.
0:19:53 > 0:19:56'Make sure you repeat each drop three times
0:19:56 > 0:19:58'so you can calculate an average.
0:20:01 > 0:20:03'Right, let's see how sharp you are!
0:20:03 > 0:20:07'Once you've all had a go, introduce the distractions.
0:20:07 > 0:20:10'This could be a mathematical sum to work out...'
0:20:10 > 0:20:1174 + 26?
0:20:13 > 0:20:15100.
0:20:15 > 0:20:18'..or a sequence of random letters
0:20:18 > 0:20:21'or different shapes and colours to remember.
0:20:21 > 0:20:23'Some of them are getting quite good at this,
0:20:23 > 0:20:27'so let's try and make it harder and introduce a second distraction.'
0:20:31 > 0:20:35Hm, green rectangle and 20.
0:20:35 > 0:20:3619.
0:20:36 > 0:20:39What seems to be going on here is that the children are getting
0:20:39 > 0:20:42better and better at doing it. The things with the distractions
0:20:42 > 0:20:44which have happened after practice,
0:20:44 > 0:20:47they're getting quite good at. One thing we can do is try
0:20:47 > 0:20:50and introduce some really difficult distractions.
0:20:50 > 0:20:52OK, right, whenever you fancy.
0:20:59 > 0:21:02So you found that pretty difficult, right?
0:21:02 > 0:21:05You see how difficult it is when you are being distracted
0:21:05 > 0:21:06by loads of different stuff.
0:21:06 > 0:21:09And that's just what it's like driving Bloodhound.
0:21:09 > 0:21:12There are all these things going on at the same time
0:21:12 > 0:21:16that are taking your attention and you still have to be able to react.
0:21:16 > 0:21:18Really difficult thing to do.
0:21:20 > 0:21:23Whether you're flying a plane or cycling a bike,
0:21:23 > 0:21:25there's always a limit to how fast you can go.
0:21:25 > 0:21:29The same is true for Bloodhound. But why is that?
0:21:29 > 0:21:32Have you any idea why it's so hard to go so fast?
0:21:32 > 0:21:34Is it because Bloodhound's really heavy?
0:21:34 > 0:21:37Is it because the engine isn't powerful enough?
0:21:37 > 0:21:39Those are both good reasons but I think what you really need
0:21:39 > 0:21:43to be looking into is what's stopping it, what's holding it back.
0:21:43 > 0:21:45And so I'd like you to look into that. OK?
0:21:50 > 0:21:53- We've come to Manchester. - Home of indoor skydiving.
0:21:53 > 0:21:55BOTH: Let's go.
0:21:57 > 0:22:00Skydivers know what it's like to travel through the air fast,
0:22:00 > 0:22:03so maybe they can give us some clues about why it will be difficult
0:22:03 > 0:22:05for Bloodhound to travel so fast.
0:22:05 > 0:22:08We've come to meet Bloodhound engineer Sarah Covel.
0:22:08 > 0:22:11She's in charge of Bloodhound's mission control,
0:22:11 > 0:22:14the nerve centre of the land speed record attempt.
0:22:15 > 0:22:19I guess you're wondering why we're here at an indoor skydiving centre.
0:22:19 > 0:22:21This is Ben. He's an international skydiver
0:22:21 > 0:22:25and he's basically going to be simulating how difficult it is
0:22:25 > 0:22:28for things like Bloodhound to move through air at high speed.
0:22:28 > 0:22:31He's travelling in wind speed of about 150 miles an hour.
0:22:31 > 0:22:34If you can imagine, Bloodhound's going to be in a wind speed
0:22:34 > 0:22:37of 1,000 miles an hour. So he's going to show us
0:22:37 > 0:22:40how difficult it is for Bloodhound to move.
0:22:40 > 0:22:44- So what do you reckon, do you want to go and have a go now?- BOTH: Yeah.
0:22:44 > 0:22:46Come on, let's go.
0:22:46 > 0:22:47- That's yours.- Oh, thank you.
0:23:00 > 0:23:03It was really difficult for them to keep still
0:23:03 > 0:23:06in the hurricane-force wind but Ben knew how to carry Nathan
0:23:06 > 0:23:08right to the top.
0:23:10 > 0:23:12So, then, boys, how did that feel?
0:23:12 > 0:23:14Well good.
0:23:14 > 0:23:16Can you imagine that ten times faster?
0:23:16 > 0:23:18No. Too fast!
0:23:19 > 0:23:22So you can imagine how difficult it's going to be,
0:23:22 > 0:23:26you trying to keep your body still in there, how hard it's going
0:23:26 > 0:23:29to be for Bloodhound to keep stable and go fast at ten times that speed.
0:23:29 > 0:23:32Andy Green's going to have a nightmare.
0:23:32 > 0:23:34If we turn the camera on its side,
0:23:34 > 0:23:39Ben looks like he's travelling horizontally, just like Bloodhound.
0:23:39 > 0:23:42And we can see how important it is to be the right shape.
0:23:43 > 0:23:47So what Ben is doing now is he's adjusting his body shape.
0:23:47 > 0:23:49So if he keeps streamlined,
0:23:49 > 0:23:51he's not got very much of a surface area.
0:23:51 > 0:23:54As he moves his body out and moves his arms out,
0:23:54 > 0:23:55his surface area increases.
0:23:55 > 0:24:00So as his surface area increases, more of the wind hits his body.
0:24:00 > 0:24:03That's how he can fly so high up. That's what we have to look at.
0:24:03 > 0:24:06With Bloodhound we need to be as streamlined as possible
0:24:06 > 0:24:09so we don't create any drag or any lift.
0:24:09 > 0:24:11As we can see, Ben's got his body quite tight in.
0:24:11 > 0:24:14As he starts to move one side of his body out further,
0:24:14 > 0:24:17he creates more lift and more drag on the side of his body,
0:24:17 > 0:24:18creating him to spin,
0:24:18 > 0:24:21because he's got more force acting on one side of his body.
0:24:21 > 0:24:25With Bloodhound we need to try and keep the car completely symmetrical
0:24:25 > 0:24:29so that when we're running along at high speed, there's no spin.
0:24:34 > 0:24:36Like Bloodhound and the skydivers,
0:24:36 > 0:24:40aeroplanes have to be the right shape to push through the air
0:24:40 > 0:24:43at high speed, which is why Nathan and James have come
0:24:43 > 0:24:45to Manchester's City Airport
0:24:45 > 0:24:48to find out how planes manage to keep stable.
0:24:48 > 0:24:52Sarah's brought them to meet pilot Mark to show them
0:24:52 > 0:24:53his microlight aircraft.
0:24:53 > 0:24:57It's a very lightweight plane, a bit like a hang glider,
0:24:57 > 0:25:02with an engine attached, which makes it easy to see how planes can fly.
0:25:02 > 0:25:04So what's this got to do with Bloodhound?
0:25:04 > 0:25:07With Bloodhound, we've got to be really careful
0:25:07 > 0:25:09not to generate any downforce or any lift,
0:25:09 > 0:25:12and, as Mark's about to show you, the smallest amount of movement
0:25:12 > 0:25:15in the wings can create a lot of lift and a lot of downforce.
0:25:15 > 0:25:18I'll pass you over to Mark and he'll explain the controls to you.
0:25:18 > 0:25:21If we push the bar forwards a tiny little bit,
0:25:21 > 0:25:24the first thing that happens is that the nose will pitch up
0:25:24 > 0:25:26and then the speed will start to drop off
0:25:26 > 0:25:28because we're producing more drag.
0:25:28 > 0:25:31We're producing more lift but we're also producing more drag.
0:25:31 > 0:25:35If we pull the bar back a tiny little bit, the nose will lower.
0:25:35 > 0:25:38We'll start to speed up but we'll also start to descend as well.
0:25:38 > 0:25:40And if we move the bar sideways from left to right,
0:25:40 > 0:25:43if we pull the left wing down, it will turn to the left.
0:25:43 > 0:25:47If we pull the right wing down, it will turn to the right.
0:25:47 > 0:25:50You can imagine tiny movements at these speeds,
0:25:50 > 0:25:53these slower speeds, make a massive difference.
0:25:53 > 0:25:56At 1,000 miles an hour, it's going to make a huge difference.
0:25:56 > 0:25:59So we really need to watch our lift and our downforce.
0:25:59 > 0:26:03What would happen if Bloodhound did create lift or downforce?
0:26:03 > 0:26:06If Bloodhound created downforce,
0:26:06 > 0:26:09the wheels are going to be forced in and we'd lose speed.
0:26:09 > 0:26:12If we created lift, there's a danger that the car could lift
0:26:12 > 0:26:14and flip back over if we created too much lift.
0:26:14 > 0:26:17So we need to watch the forces very carefully
0:26:17 > 0:26:20and we've got winglets on the side of the car,
0:26:20 > 0:26:22like the wing of this microlight,
0:26:22 > 0:26:25that adjust constantly to stop that from happening.
0:26:25 > 0:26:26OK, let's go!
0:26:26 > 0:26:29Now it's James's turn to fly in the microlight
0:26:29 > 0:26:32and, amazingly, after reaching just 40 miles an hour,
0:26:32 > 0:26:35pushing the bar forward is enough to get airborne.
0:26:35 > 0:26:38Woah!
0:26:38 > 0:26:40Woo-hoo!
0:26:40 > 0:26:44And just tiny movements on the bar is enough to make the microlight
0:26:44 > 0:26:46turn sharply through the air. Watch out!
0:26:50 > 0:26:54That's cool but it's scary at the same time.
0:27:01 > 0:27:03Touchdown!
0:27:03 > 0:27:05Bouncy, bouncy.
0:27:08 > 0:27:12So once the steering has been taken care of,
0:27:12 > 0:27:15and with the power of a fighter jet engine on board,
0:27:15 > 0:27:17you'd think Bloodhound would have no problem breaking
0:27:17 > 0:27:21the land speed record but it's not as simple as that.
0:27:21 > 0:27:24Right, guys, the reason we're down at the pool today is to try
0:27:24 > 0:27:28and help us demonstrate how Bloodhound needs to work really hard
0:27:28 > 0:27:29to cut through the air.
0:27:29 > 0:27:31So, James, I want you to be a fast jet plane
0:27:31 > 0:27:34trying to fly along at ground level.
0:27:34 > 0:27:36Nathan, I want you to be a jet plane trying to fly along
0:27:36 > 0:27:39at high altitude, so 40,000 feet.
0:27:39 > 0:27:43When I tell you to I want you to race to the other end of the pool.
0:27:43 > 0:27:48So on your marks...get set, go!
0:27:52 > 0:27:53Come on, James.
0:27:53 > 0:27:57You might not think it but there are similarities between air and water,
0:27:57 > 0:27:59but of course water is much denser.
0:27:59 > 0:28:04When you move through them, both air and water have to flow past you.
0:28:04 > 0:28:06For James, pushing through water
0:28:06 > 0:28:08is what it's like for a jet plane at ground level
0:28:08 > 0:28:12because the air is so much thicker and it slows you down.
0:28:12 > 0:28:15At high altitude, the air is much thinner
0:28:15 > 0:28:20and easier to push through so you can travel a lot faster.
0:28:20 > 0:28:22Winner! Come on, James. Come on
0:28:22 > 0:28:25Come on, James!
0:28:25 > 0:28:27You took 12 seconds.
0:28:27 > 0:28:29You took 44 seconds.
0:28:29 > 0:28:31There's a big difference there, yeah?
0:28:31 > 0:28:34So what the pool is showing us is that, actually, air density
0:28:34 > 0:28:37at ground level is a lot higher, the air's a lot thicker
0:28:37 > 0:28:40and there's more resistance so you've got to work harder.
0:28:40 > 0:28:43Nathan, it was a lot easier for you - the air's a lot thinner.
0:28:43 > 0:28:45Ultimately it shows us
0:28:45 > 0:28:48Bloodhound has to work extremely hard to cut through the air.
0:28:48 > 0:28:52So what have you learnt about the problems of travelling really fast?
0:28:52 > 0:28:54You've been doing some really cool stuff.
0:28:54 > 0:28:59Yeah, we've been indoor skydiving and we've also been in a microlight.
0:28:59 > 0:29:01When you're travelling at a high speed,
0:29:01 > 0:29:05it's quite hard to push through the air resistance.
0:29:05 > 0:29:08Right. And so air resistance is a massive problem with this.
0:29:08 > 0:29:11And have you come across anything else?
0:29:11 > 0:29:14When we were in the microlight, the man made a little adjustment
0:29:14 > 0:29:17and it just swerved and you think you're going to fall out.
0:29:17 > 0:29:20But you're not and it's just dead scary.
0:29:20 > 0:29:23What's happening here is these little winglets on Bloodhound,
0:29:23 > 0:29:25they can be adjusted a tiny amount
0:29:25 > 0:29:28and that changes how the air flows over the body.
0:29:28 > 0:29:31But it's really difficult to get the engineering right
0:29:31 > 0:29:33so that the whole thing stays on the ground.
0:29:33 > 0:29:36If you do get it right, you can be a world record breaker.
0:29:53 > 0:29:56Fighter jets can travel really fast
0:29:56 > 0:29:59but even a fighter jet can't get to 1,000 miles an hour
0:29:59 > 0:30:01if it's at ground level,
0:30:01 > 0:30:04which is the speed Bloodhound is designed to go at.
0:30:04 > 0:30:07That's because at ground level there's much more air
0:30:07 > 0:30:09and it becomes really difficult
0:30:09 > 0:30:13when you go fast to push all that air out of the way in time.
0:30:13 > 0:30:16And here at Links Primary School in South London
0:30:16 > 0:30:18we're going to investigate
0:30:18 > 0:30:21how Bloodhound is designed to deal with that.
0:30:21 > 0:30:23So you probably don't think of air
0:30:23 > 0:30:26anything like water over there, do you?
0:30:26 > 0:30:27ALL: No.
0:30:27 > 0:30:30No, but they are both quite similar, actually.
0:30:30 > 0:30:33They both flow around things, they are both fluids.
0:30:33 > 0:30:36It's just that air is quite light and water is quite dense,
0:30:36 > 0:30:39it's quite hard to push out of the way.
0:30:39 > 0:30:40We'll be messing around with water
0:30:40 > 0:30:43to show you how to design things that go really fast.
0:30:43 > 0:30:47Here, we're going to drop two pieces of modelling clay into water
0:30:47 > 0:30:51to show that increasing the power alone isn't enough to travel
0:30:51 > 0:30:53through water quickly. I'm going to drop mine
0:30:53 > 0:30:56and my volunteer is going to throw hers in as hard as she can.
0:30:56 > 0:30:59And everyone else can look and see if they hit...
0:30:59 > 0:31:01which one hits first, OK?
0:31:01 > 0:31:04And I'll do three, two, and one and then we'll throw, yeah, OK?
0:31:04 > 0:31:06Three, two, one. Go!
0:31:06 > 0:31:09It's about the same! It's really hard.
0:31:09 > 0:31:12If you are going really fast,
0:31:12 > 0:31:15things slow down so quickly that basically it makes no difference.
0:31:15 > 0:31:19But we're going to show the big difference it makes
0:31:19 > 0:31:21if you just change the shape of the Plasticine.
0:31:21 > 0:31:24You'll need two large drinks bottles with the tops cut off.
0:31:24 > 0:31:27Fill them with equal amounts of water
0:31:27 > 0:31:30and then you'll need two pieces of modelling clay,
0:31:30 > 0:31:32which must be the same size.
0:31:32 > 0:31:36With one piece, mould a flat shape like the one I've just used,
0:31:36 > 0:31:39and with the other, experiment making different shapes to see how
0:31:39 > 0:31:42quickly they travel through the water.
0:31:42 > 0:31:44Make sure you drop them at the same time,
0:31:44 > 0:31:48so you can compare the two accurately.
0:31:48 > 0:31:51So when you are trying to make things go fast through water,
0:31:51 > 0:31:54think of shapes of things that you know go really fast.
0:31:56 > 0:32:00OK, so have a go yourselves and see which shapes are the fastest.
0:32:01 > 0:32:05Our two best performers are the green ball and the red dart
0:32:05 > 0:32:08so let's put them head to head and test them in the big tank
0:32:08 > 0:32:10to see which one is the quickest.
0:32:10 > 0:32:13Yes! Ooohh!
0:32:16 > 0:32:18Did you notice what happened?
0:32:18 > 0:32:22As soon as these ones move sideways, they slow down.
0:32:22 > 0:32:25So if they go straight all the way through the water they are fine,
0:32:25 > 0:32:28but as soon as they turn side on, they are no good!
0:32:28 > 0:32:31What do you think we could do about that? Go on.
0:32:31 > 0:32:32Put fins on it?
0:32:32 > 0:32:35Yeah, you could put something at the end, like a fin,
0:32:35 > 0:32:38that makes sure it carries going straight all the way through.
0:32:38 > 0:32:39Let's try it with this one.
0:32:39 > 0:32:42The fins need to be really thin, though.
0:32:42 > 0:32:45Could try something like that, I guess.
0:32:47 > 0:32:49Three, two, one...
0:32:52 > 0:32:56This action replay clearly shows that the streamline shape
0:32:56 > 0:33:01of the red dart with fins for added stability makes it a clear winner.
0:33:01 > 0:33:03So this fast shape...
0:33:03 > 0:33:06Well, it's a bit like Bloodhound, really, isn't it?
0:33:06 > 0:33:10A pointy front and fins at the back
0:33:10 > 0:33:14keeps it going straight. That's how to go really fast.
0:33:23 > 0:33:27It's one thing going fast, 1,000 miles an hour, but how do you stop?
0:33:27 > 0:33:30Anyone, any ideas about how you slow this thing down?
0:33:30 > 0:33:31Maybe some brakes?
0:33:31 > 0:33:34Maybe a rocket in the other direction?
0:33:34 > 0:33:36Those are both good ideas but there's a lot more
0:33:36 > 0:33:40to slowing down than you might think, so see what you can discover.
0:33:44 > 0:33:47We've come to Santa Pod in Northamptonshire.
0:33:47 > 0:33:50- Home of the fastest motor sport on earth.- Let's go!
0:34:06 > 0:34:10We've come to meet Bloodhound engineer Annie Berrisford.
0:34:10 > 0:34:12And away from the track we found a car that looks
0:34:12 > 0:34:15a bit like Bloodhound - it's long and thin.
0:34:15 > 0:34:18So we asked Annie how this car compares to Bloodhound.
0:34:18 > 0:34:21OK, guys, so this is the Split Second car.
0:34:21 > 0:34:22It's a jet-powered drag car,
0:34:22 > 0:34:25so that means it's powered by this jet engine
0:34:25 > 0:34:28and it goes in a straight line, just like Bloodhound does.
0:34:28 > 0:34:30So Bloodhound also has a jet engine
0:34:30 > 0:34:33and is designed to go only in a straight line.
0:34:33 > 0:34:35This is Julian, who is the driver,
0:34:35 > 0:34:38who's the mad guy sitting in the small cockpit there.
0:34:38 > 0:34:40How fast do think this car can go?
0:34:40 > 0:34:42Top speed, about 360 miles an hour.
0:34:42 > 0:34:46So if it's going that fast, how do you think we slow this car down?
0:34:46 > 0:34:48- BOTH: Parachutes. - Parachutes, that's right.
0:34:48 > 0:34:51We've got two parachutes sitting at the back of the car.
0:34:51 > 0:34:54Every time, we use one parachute, there's a second parachute.
0:34:54 > 0:34:57If that goes wrong, we've got the second just in case.
0:34:57 > 0:35:01It's nice to know you're not going to go off the end of the track.
0:35:01 > 0:35:04We asked Annie if there are any other types of brakes on the car.
0:35:04 > 0:35:07OK, so not only has this car got parachutes at the back
0:35:07 > 0:35:10of the car, it's actually got wheel brakes as well on the front
0:35:10 > 0:35:12of the car and on the rear wheels.
0:35:12 > 0:35:15So why do these have to have brakes?
0:35:15 > 0:35:18This has brakes purely to stop it at very low speeds
0:35:18 > 0:35:20and to hold it on the start line.
0:35:20 > 0:35:23If you were to use these when the car was going as fast as it does,
0:35:23 > 0:35:24it would burn out the brakes.
0:35:24 > 0:35:27So you need the parachutes for the high-speed running
0:35:27 > 0:35:29and wheel brakes for the low-speed running.
0:35:29 > 0:35:33- Will Bloodhound have brakes? - Yeah, Bloodhound also has brakes.
0:35:33 > 0:35:35But exactly the same as on this car, we'll use them
0:35:35 > 0:35:37to hold the car on the start line
0:35:37 > 0:35:40and then also to just slow it down at lower speeds,
0:35:40 > 0:35:41so below 100 miles an hour.
0:35:44 > 0:35:47Back on the track, it's time to take the car for a run.
0:35:47 > 0:35:52Julian uses his wheel brakes to line up on the starting line.
0:35:59 > 0:36:02And after a mega fast run reaching just under 230 miles an hour,
0:36:02 > 0:36:07it's the parachutes that slow him down, just like Bloodhound will do.
0:36:07 > 0:36:10The difference is that Bloodhound will go four times as fast,
0:36:10 > 0:36:14which is faster than a bullet fired from a gun.
0:36:14 > 0:36:17You don't have to be a grown-up to join in the fun.
0:36:17 > 0:36:20Some children as young as eight do this sport.
0:36:20 > 0:36:25Meet 13-year-old Paige Wheeler and her little sister Belle.
0:36:27 > 0:36:29Paige started the sport when she was just ten
0:36:29 > 0:36:32but her eight-year-old sister is officially
0:36:32 > 0:36:34the world's youngest dragster racer.
0:36:34 > 0:36:36Well, this is my car.
0:36:38 > 0:36:41I have a parachute here. Then I have the big tyres.
0:36:41 > 0:36:44They're mainly that big so that,
0:36:44 > 0:36:46you know, I can get a lot of traction on the track
0:36:46 > 0:36:48so I can go faster.
0:36:48 > 0:36:50This is my engine.
0:36:50 > 0:36:53And then my car's really skinny at the front and big at the back
0:36:53 > 0:36:58because it needs to be aerodynamic so it can go faster.
0:36:58 > 0:37:00What's it like to drive your car?
0:37:00 > 0:37:03When I first put my foot down, my head goes right back into the seat.
0:37:03 > 0:37:05It actually really hurts.
0:37:05 > 0:37:06How fast do you go?
0:37:06 > 0:37:09My top speed is 86 miles per hour,
0:37:09 > 0:37:12but we're restricted to 85.
0:37:12 > 0:37:15Although her car is a lot smaller than Bloodhound,
0:37:15 > 0:37:18Paige has to consider all the same things -
0:37:18 > 0:37:22how to accelerate as quickly as possible with her engine
0:37:22 > 0:37:24and then how to slow down with her brakes
0:37:24 > 0:37:27before running off the end of the track - all in a matter of seconds.
0:37:32 > 0:37:34This is what it's like for her
0:37:34 > 0:37:36travelling at up to 80 miles an hour.
0:37:36 > 0:37:40Imagine what it will be like for Bloodhound's driver,
0:37:40 > 0:37:44Andy Green, travelling over 12 times faster at 1,000 miles an hour.
0:37:46 > 0:37:48So we know how Bloodhound will slow down
0:37:48 > 0:37:51but just how quickly will it slow down?
0:37:52 > 0:37:56Back at the racing track, we asked Bloodhound team-mate Conor
0:37:56 > 0:37:59to help us find out how quickly brakes can stop a car.
0:38:01 > 0:38:04You guys are going to put these boxes where you think is best,
0:38:04 > 0:38:07in the middle of the road.
0:38:07 > 0:38:09OK, guys, so look over to the side of the track.
0:38:09 > 0:38:12The end of those green barriers there, that's where Simon,
0:38:12 > 0:38:15our friendly racing driver, is going to start braking.
0:38:15 > 0:38:17He's in a family car, the surface is quite grippy.
0:38:17 > 0:38:21Nice, grippy tyres, racing driver - he will be good at the brakes.
0:38:21 > 0:38:24Have a think. It's your guess how far it will take him to stop.
0:38:24 > 0:38:25Don't want to hit the boxes
0:38:25 > 0:38:28but we want to get it close. 60 miles an hour.
0:38:28 > 0:38:32So that's almost like motorway speed in your mum and dad's cars.
0:38:32 > 0:38:35You think? So that's starting from here.
0:38:35 > 0:38:38You think that's enough?
0:38:40 > 0:38:42Further. 60 miles an hour.
0:38:43 > 0:38:4460.
0:38:45 > 0:38:47- There.- There?- Yeah.
0:38:47 > 0:38:49- Do you think we should get out the way, then?- Yep.
0:38:49 > 0:38:52I think we probably should, come this side.
0:38:52 > 0:38:54You pretty much chose around the same distance.
0:38:54 > 0:38:58You're both putting the boxes down round the same point.
0:38:58 > 0:39:01- How far do you think that is? Five metres? Ten metres?- Um...
0:39:01 > 0:39:03Yeah, about nine.
0:39:03 > 0:39:04Maybe nine metres?
0:39:04 > 0:39:06Seven.
0:39:06 > 0:39:09'When racing driver Simon gets to the end of the green barrier,
0:39:09 > 0:39:12'he'll slam on the brakes.
0:39:12 > 0:39:14'Let's see what happens.'
0:39:17 > 0:39:18What do you think, guys?
0:39:18 > 0:39:20- Were you expecting that? - BOTH: No.
0:39:20 > 0:39:22- It took longer that you thought. - Yeah.
0:39:22 > 0:39:25And that's with the really grippy tyres with a racing driver
0:39:25 > 0:39:27on a really clean grippy circuit.
0:39:27 > 0:39:32So, stopping - more of a challenge than you thought, yeah?
0:39:32 > 0:39:35- How far off do you think you were? - About half.- About half.
0:39:35 > 0:39:39Do you think Simon started braking early as well? I think he did.
0:39:39 > 0:39:42I think he was worried about hitting the boxes in his car.
0:39:42 > 0:39:44Braking, slowing something down,
0:39:44 > 0:39:47is a huge challenge and almost as difficult as getting it to go fast.
0:39:47 > 0:39:49Really important to do it safely.
0:39:52 > 0:39:56So what have you learnt about how Bloodhound is going to slow down?
0:39:56 > 0:39:59It's going to need a lot of space to slow down.
0:39:59 > 0:40:03The car will be going too fast for normal brakes, so it will overheat.
0:40:03 > 0:40:05I think it'll use a parachute.
0:40:05 > 0:40:08Yeah, it's also going to use these things on the side here,
0:40:08 > 0:40:12which are called air brakes. They pop out and as the air hits them,
0:40:12 > 0:40:14it slows down, it creates something called drag
0:40:14 > 0:40:17and that's what the parachute does as well.
0:40:17 > 0:40:20When the parachutes pop out, the air gets caught in them, causes drag
0:40:20 > 0:40:22and that's how this slows down.
0:40:22 > 0:40:26It's going to be quite an experience for Andy Green to slow down so fast.
0:40:48 > 0:40:53Bloodhound is travelling so fast that brakes alone
0:40:53 > 0:40:55aren't enough to stop it,
0:40:55 > 0:40:58so it uses a couple of different ways of stopping
0:40:58 > 0:41:00and one of those is a parachute.
0:41:00 > 0:41:02I'm at Links Primary School
0:41:02 > 0:41:05to investigate what makes a good parachute.
0:41:05 > 0:41:08- Have any of you made a parachute before?- No!
0:41:08 > 0:41:13If I have a tissue like this and I just drop it... Whoa.
0:41:13 > 0:41:15Yeah?
0:41:15 > 0:41:18But if I just squish it up like that and then drop it,
0:41:18 > 0:41:20what's going to happen?
0:41:20 > 0:41:21So why does that happen?
0:41:23 > 0:41:27Because in a parachute, it has to be flat
0:41:27 > 0:41:30but when you put it in a ball,
0:41:30 > 0:41:32no air can push it up, so it goes directly down.
0:41:32 > 0:41:36Exactly, so it needs a big, what's called a surface area,
0:41:36 > 0:41:39it needs a big area to catch all that air as it comes down
0:41:39 > 0:41:41and that's really what makes a good parachute.
0:41:41 > 0:41:45So we've got cloths, string, Sellotape, card
0:41:45 > 0:41:49and you are going to have to work out how to make your own parachute
0:41:49 > 0:41:52and stop an egg from breaking. OK?
0:41:52 > 0:41:54Let's get cracking!
0:41:54 > 0:41:57Why don't you try making your own parachute?
0:41:57 > 0:42:00Think about other materials that you could use.
0:42:04 > 0:42:09We've decided to make a hot air balloon design, so it will catch it
0:42:09 > 0:42:12and we're going to put the egg in that cup there,
0:42:12 > 0:42:16and the cup will sort of be a cushion.
0:42:22 > 0:42:26OK, it's time to put some of these designs to the test.
0:42:26 > 0:42:28Three, two, one...
0:42:31 > 0:42:33Yeah, fine!
0:42:35 > 0:42:38Right, I think this ground is too soft.
0:42:38 > 0:42:40None of the eggs are breaking, it's just far too easy.
0:42:40 > 0:42:43I'm going to have to make this a bit more challenging!
0:42:43 > 0:42:47Let's go over here and I'll climb up on the roof!
0:42:48 > 0:42:50- Hiya!- Yeah!
0:42:51 > 0:42:55- So shall I try them one by one, yeah?- Yeah!
0:42:55 > 0:42:57OK, ready?
0:42:58 > 0:43:00- Arrgh! - LAUGHTER
0:43:03 > 0:43:06Not bad.
0:43:06 > 0:43:07Did it survive?
0:43:07 > 0:43:09A tiny bit, just a tiny bit.
0:43:09 > 0:43:12So who just Sellotaped an egg to a plastic bag?!
0:43:18 > 0:43:20Well and truly scrambled!
0:43:22 > 0:43:25< Three, two, one!
0:43:27 > 0:43:31It survived! It survived, yeah!
0:43:33 > 0:43:37- So did you see what happened there? - Yeah.- Quite a lot of them broke,
0:43:37 > 0:43:40but the best ones were the ones that floated down really slowly,
0:43:40 > 0:43:44that caught lots of air and also had some cushioning on the bottom.
0:43:44 > 0:43:48So Bloodhound uses a parachute, amongst other things, to slow down.
0:43:48 > 0:43:51It's very effective when you catch lots of air.
0:43:54 > 0:43:57We're on a mission to find out what's needed to build
0:43:57 > 0:43:59the world's fastest car.
0:43:59 > 0:44:02Now, just like a normal car, Bloodhound has wheels.
0:44:02 > 0:44:05But there's something very different about them. Have you noticed what?
0:44:05 > 0:44:09Well, maybe my willing investigators have found something out.
0:44:09 > 0:44:12So like any normal car, Bloodhound has four wheels.
0:44:12 > 0:44:16But what's different about them? Have you noticed anything?
0:44:16 > 0:44:18It doesn't have any tyres.
0:44:18 > 0:44:21Yes, it doesn't have any tyres. And there's a very good reason for that.
0:44:21 > 0:44:24And what I'd like you to do is find out why.
0:44:28 > 0:44:33Unlike a normal car, Bloodhound only has to go in a straight line
0:44:33 > 0:44:38to break the land speed record, but surely it still needs tyres?
0:44:38 > 0:44:41We've come to Mallory Park racing track in Leicestershire.
0:44:41 > 0:44:43And we're going to burn some rubber!
0:44:46 > 0:44:51Hundreds of different types of cars use this track every day,
0:44:51 > 0:44:53from racing cars to motorbikes.
0:44:53 > 0:44:56So where better to try to find out why tyres are normally
0:44:56 > 0:44:58so important for driving?
0:44:58 > 0:45:01At the track today is Bloodhound team mate Conor
0:45:01 > 0:45:03and racing driver Simon.
0:45:03 > 0:45:06They've put a swingometer device on top of the car,
0:45:06 > 0:45:08so what on earth is that all about?
0:45:08 > 0:45:12And more importantly, what's it got to do with Bloodhound?
0:45:13 > 0:45:16We're going to go on the track this time with Simon in this car.
0:45:16 > 0:45:20We're going to use this arrow to show what's going on with this car
0:45:20 > 0:45:22as the tyres grip as we go through the bends.
0:45:22 > 0:45:26When we're in the car and feel our bodies being thrown left and right,
0:45:26 > 0:45:30we'll chat and try and figure out which way we think the arrow's going
0:45:30 > 0:45:33and which way the forces are acting on us in the car
0:45:33 > 0:45:35- as it goes round the bends. OK?- Yep.
0:45:37 > 0:45:40We wouldn't be able to drive along like this if we didn't have tyres.
0:45:40 > 0:45:42Simon would put his foot on the throttle
0:45:42 > 0:45:45and probably the wheels would just spin and spin and spin.
0:45:45 > 0:45:47Feel the grip. Feel the tyre gripping,
0:45:47 > 0:45:49pushing you right over that side.
0:45:49 > 0:45:52Which way did you feel yourselves going?
0:45:52 > 0:45:53Left then right.
0:45:53 > 0:45:57Get ready for another change, another change. Well done.
0:45:57 > 0:46:00When you go into the corner, the car rolls one way.
0:46:00 > 0:46:05You change direction and the car rolls the other way.
0:46:05 > 0:46:07And if there were no tyres on these wheels,
0:46:07 > 0:46:09we'd just slip straight off the track,
0:46:09 > 0:46:12because there is very little grip without having the rubber.
0:46:12 > 0:46:17- Feel the forces and when we go left, which way does your body go?- Right.
0:46:17 > 0:46:19- And when we go right, which way does your body go?- Left.
0:46:19 > 0:46:22Which way do you think the arrow on the roof went? Same as you?
0:46:22 > 0:46:26Same as you. Is that how your mum and dad drive?
0:46:26 > 0:46:28- No.- My dad does. He's a maniac.
0:46:32 > 0:46:36But having tyres doesn't always mean your car will stay on the road.
0:46:36 > 0:46:39We wanted to know why these cars were spinning even with tyres.
0:46:39 > 0:46:42So we asked Bloodhound team-mate Annie Beresford.
0:46:42 > 0:46:48OK, guys, what we've got here is cars doing drifting.
0:46:48 > 0:46:51So they've got normal road tyres on,
0:46:51 > 0:46:54exactly like what you've got on your car that you came in today,
0:46:54 > 0:46:57but I bet you weren't driving like this.
0:46:57 > 0:47:00Now, your tyres are normally giving you the grip
0:47:00 > 0:47:04that you need to stay on the road and drive sensibly round corners.
0:47:04 > 0:47:07These guys are actually spinning their wheels so fast
0:47:07 > 0:47:11that they're losing that grip and enabling them to slide.
0:47:11 > 0:47:13We're really lucky with Bloodhound
0:47:13 > 0:47:15in that we're going in a straight line only
0:47:15 > 0:47:18so we don't actually have to go round any corners.
0:47:18 > 0:47:21Bloodhound's wheels will need to travel so fast,
0:47:21 > 0:47:26they'd also lose grip. Tyres would get so hot, they'd explode.
0:47:26 > 0:47:30If Bloodhound had tyres, the grip would actually slow the car down.
0:47:30 > 0:47:33But not having any tyres comes at a price.
0:47:33 > 0:47:37You saw how important tyres are in that car whizzing round the track.
0:47:37 > 0:47:40Have a play on these bikes and see how important tyres are on a bike
0:47:40 > 0:47:43- and see whether you can spot a difference, OK?- Yep.
0:47:43 > 0:47:46So jump on, go for a ride around, then we'll have a chat.
0:47:46 > 0:47:47Ready, guys? Off you go.
0:47:54 > 0:47:57There's something very strange about Anton's bike
0:47:57 > 0:48:01that's making it very difficult to steer and so bumpy.
0:48:02 > 0:48:04How was that?
0:48:04 > 0:48:05- Bumpy.- Slippy?- Yeah.
0:48:05 > 0:48:08Did you feel like you were going to fall off at all? Wobbly?
0:48:08 > 0:48:11Yeah, when I was turning back round, I felt like I was going to slip.
0:48:11 > 0:48:15We saw your back wheel was all over the place because there's no tyre.
0:48:15 > 0:48:19You were fine because you had lovely squashy tyres, nice and grippy.
0:48:19 > 0:48:22- Could you do that every day or was that a one-off?- One-off.- One-off.
0:48:22 > 0:48:26So on the road, on bikes, tyres are a great thing.
0:48:26 > 0:48:29But for Bloodhound, we're too fast for tyres.
0:48:29 > 0:48:33The fastest tyres in the world, 450 miles an hour, we're going 1,000,
0:48:33 > 0:48:35so Bloodhound has solid wheels.
0:48:35 > 0:48:38Just like you, we're running on the rims, no tyres.
0:48:38 > 0:48:40So we have to design that into the car.
0:48:40 > 0:48:43Bloodhound's wheels are also really thin for such a big car
0:48:43 > 0:48:45and we wanted to know why.
0:48:45 > 0:48:47It's time to get our skates on.
0:48:56 > 0:49:00- How did you find that? Was it good? - Yeah, slippy.- Slippery.
0:49:00 > 0:49:03Really slippy? Why do you think that was so slippy?
0:49:03 > 0:49:05Is it because our blades on our shoes are really thin?
0:49:05 > 0:49:07Yeah, your blades are really thin
0:49:07 > 0:49:10and you're on a really, really slippy surface
0:49:10 > 0:49:12and there's very little friction between the two.
0:49:12 > 0:49:16Whereas if you were to step onto the Tarmac, it's really grippy
0:49:16 > 0:49:19and you wouldn't slide anywhere - like Bloodhound.
0:49:19 > 0:49:23We've actually got very thin wheels so we can cut through the ground
0:49:23 > 0:49:27very, very easily and there's not a lot of friction on those wheels.
0:49:27 > 0:49:30It also means stopping and slowing down is harder for us.
0:49:30 > 0:49:34We can't use wheel brakes because the wheels will slide quite easily.
0:49:38 > 0:49:41So what have you learnt about Bloodhound's wheels?
0:49:41 > 0:49:44The wheels are made out of aluminium and if they were proper tyres,
0:49:44 > 0:49:47- at high speed they would explode. - Right, OK, anything else?
0:49:47 > 0:49:49Yes, the Bloodhound car did not have any tyres
0:49:49 > 0:49:53because the tyres would grip to the ground and make it go slower.
0:49:53 > 0:49:57OK, but if it doesn't have tyres, it must be really bumpy, yeah?
0:49:57 > 0:50:02A normal car would have tyres to go round the bend, but the Bloodhound
0:50:02 > 0:50:06does not need tyres because it is going in a straight line.
0:50:06 > 0:50:08Well, glad I'm not riding it!
0:50:24 > 0:50:27Bloodhound is designed to go at 1,000 miles an hour,
0:50:27 > 0:50:30and that's going to make it the fastest car in the world.
0:50:30 > 0:50:33But although, like a normal car,
0:50:33 > 0:50:36it's got wheels, it doesn't have any tyres.
0:50:36 > 0:50:39We're here at Links Primary School in South London
0:50:39 > 0:50:41to try and find out why that is.
0:50:41 > 0:50:45So do you know why a normal car has tyres? Go on, then.
0:50:45 > 0:50:49- To grip onto the road?- Yeah, and that grip is called friction.
0:50:49 > 0:50:52Here's a really quick demo to show how powerful friction is.
0:50:52 > 0:50:55Interlace the pages of two paperback books
0:50:55 > 0:50:59and see if you can pull them apart.
0:50:59 > 0:51:02Arrgghh. It's pretty strong.
0:51:02 > 0:51:06All that's holding those together is the friction between the pages.
0:51:06 > 0:51:10The harder you pull, the more they push together
0:51:10 > 0:51:11and the more friction there is.
0:51:11 > 0:51:13Do you want to have a go?
0:51:16 > 0:51:19But Bloodhound isn't using the tyres to power it,
0:51:19 > 0:51:21it's using a jet engine and a rocket,
0:51:21 > 0:51:24and so it doesn't need to grip the road like that.
0:51:24 > 0:51:26And, besides, it's not even going round corners,
0:51:26 > 0:51:29so it doesn't need the tyres to grip when going around corners.
0:51:29 > 0:51:33Even if it did have tyres, the tyres might be in a bit of trouble.
0:51:33 > 0:51:35I'll show you why, but it's going to get messy!
0:51:38 > 0:51:41For this bit, all you're going to need is a turntable,
0:51:41 > 0:51:46or something similar that spins round, and some jelly.
0:51:46 > 0:51:49We'll put that in the middle, yeah?
0:51:49 > 0:51:51Eww, it looks like bogey!
0:51:55 > 0:51:57Do you want to try spinning it?
0:51:57 > 0:51:59Bit faster.
0:51:59 > 0:52:02- Can you see what's happening to it? - I think...
0:52:10 > 0:52:14- So did you see what was happening there to the jelly?- Yeah.
0:52:14 > 0:52:18- So what was happening? - It was spreading around
0:52:18 > 0:52:22and then the force was taking it in different directions.
0:52:22 > 0:52:26Absolutely, the forces on it were just throwing it in all directions.
0:52:26 > 0:52:29- It just went splurrtt, didn't it? - It's like an explosion.
0:52:29 > 0:52:33That's what would happen to tyres if they went that fast on Bloodhound.
0:52:40 > 0:52:42If you're doing this at home
0:52:42 > 0:52:45or if you don't have a turntable, try raiding the kitchen cupboards
0:52:45 > 0:52:48and see if you can find a salad spinner.
0:52:48 > 0:52:50Right, let's spin it up!
0:52:56 > 0:52:59- Let's take the lid off! - Where's it all gone?!
0:52:59 > 0:53:00That really has disintegrated.
0:53:00 > 0:53:04- Look, it's all coming out of the bottom as well!- Ugh!
0:53:04 > 0:53:08So this is what would happen to car tyres going at that sort of speed.
0:53:08 > 0:53:11They would just completely disintegrate! Look at that!
0:53:18 > 0:53:19All cars need an engine,
0:53:19 > 0:53:23but where do you get one that gets you to 1,000 miles an hour?
0:53:23 > 0:53:27Well, that's the challenge for our team of investigators to find out.
0:53:27 > 0:53:28So it's a big car.
0:53:28 > 0:53:32Have you spotted anything that would propel it forward?
0:53:32 > 0:53:36- It seems to have two enormous exhausts.- Well spotted.
0:53:36 > 0:53:39What do you think is going to go in there, and in there?
0:53:39 > 0:53:40That's for you to find out.
0:53:58 > 0:54:04We're here at a secret rocket testing centre in Buckinghamshire.
0:54:04 > 0:54:05Shhhh, this way.
0:54:15 > 0:54:19Hello there. Welcome to the Bloodhound rocket test site.
0:54:19 > 0:54:22My name's Daniel Jubb. I'm the rocket scientist on Bloodhound SSC.
0:54:22 > 0:54:25- Would you like to find out more about how rockets work?- Yes!
0:54:25 > 0:54:28Excellent, let's go and do some experiments.
0:54:38 > 0:54:41So what has tug-of-war got to do with rockets and Bloodhound?
0:54:41 > 0:54:45To understand how rockets work and what makes Bloodhound move,
0:54:45 > 0:54:48you have to understand about forces.
0:54:48 > 0:54:51You're both exerting a force on this rope, but it's not moving,
0:54:51 > 0:54:54so the forces are balanced. But if you introduce a larger force,
0:54:54 > 0:54:57like the thrust from a rocket or a jet engine,
0:54:57 > 0:54:59we can start things moving.
0:54:59 > 0:55:01Stop!
0:55:04 > 0:55:07But to accelerate to 1,000 miles an hour,
0:55:07 > 0:55:11Bloodhound is going to need a huge force to push it along.
0:55:11 > 0:55:15Although it will have a fighter jet engine, that won't be enough.
0:55:15 > 0:55:16It's going to need a rocket.
0:55:19 > 0:55:22This is the kind of rocket you may be familiar with - a firework.
0:55:22 > 0:55:25It works on the same principle we're going to use
0:55:25 > 0:55:28to propel Bloodhound across the desert at 1,000 miles an hour.
0:55:28 > 0:55:30We have gunpowder inside this rocket.
0:55:30 > 0:55:35Now, that's a mixture of a fuel and an oxidizer in solid form.
0:55:35 > 0:55:38When we ignite that, it generates a huge volume of hot gas.
0:55:38 > 0:55:41We expand those hot gasses through a nozzle
0:55:41 > 0:55:44and accelerate them rearward at very high speed.
0:55:44 > 0:55:46That produces a force - thrust -
0:55:46 > 0:55:49acting on the rocket to propel it forwards.
0:55:59 > 0:56:01- Wow!- That's amazing!
0:56:08 > 0:56:11So to generate that enormous volume of hot gas in a rocket,
0:56:11 > 0:56:12you need to burn a fuel.
0:56:14 > 0:56:17Daniel showed us just how powerful some solid fuels can be.
0:56:17 > 0:56:20The secret is they contain their own oxygen,
0:56:20 > 0:56:22which everything needs to burn well.
0:56:22 > 0:56:24But Bloodhound's going to need
0:56:24 > 0:56:26something more advanced than a fireworks rocket.
0:56:26 > 0:56:29Cool!
0:56:29 > 0:56:33Instead, it's going to use a mixture of solid fuel
0:56:33 > 0:56:37and this special liquid called HTP, high-test peroxide,
0:56:37 > 0:56:39which is so reactive, it instantly burns the fuel.
0:56:39 > 0:56:42It doesn't even need a match to light it.
0:56:42 > 0:56:44This really is rocket science!!
0:56:44 > 0:56:45Now, in Bloodhound,
0:56:45 > 0:56:49we're using a very large quantity of high-test peroxide
0:56:49 > 0:56:51to burn a rubber fuel in our hybrid rocket.
0:56:51 > 0:56:54Should have brought some marshmallows!
0:57:00 > 0:57:03So what's this contraption?
0:57:03 > 0:57:04This is the six-inch hybrid rocket
0:57:04 > 0:57:07that we've been developing for Bloodhound.
0:57:07 > 0:57:10It's not the full-size one that's going to go on the car.
0:57:10 > 0:57:14The full-size one will be three times the diameter and twice as long,
0:57:14 > 0:57:17but it will actually produce about ten times as much thrust.
0:57:17 > 0:57:21In this combustion chamber, we've got our solid fuel
0:57:21 > 0:57:26and in this big tank behind us, we've got our hydrogen peroxide, HTP.
0:57:26 > 0:57:28Which way will the car move?
0:57:28 > 0:57:32The car moves forwards and the rocket exhaust is firing out the door.
0:57:32 > 0:57:34So the gasses are being pushed in that direction
0:57:34 > 0:57:38and that's exerting a force in this direction against the stand.
0:57:38 > 0:57:40Would you like to see the control room
0:57:40 > 0:57:43- and watch a video of the rocket firing?- Yes!- Let's go!
0:57:43 > 0:57:48Five...four...three...two...one...
0:57:48 > 0:57:51ignition.
0:57:54 > 0:57:57Wow! I wouldn't like to have that
0:57:57 > 0:58:00going off in the back of my mum and dad's car!
0:58:02 > 0:58:07So what have you learnt about how Bloodhound's going to go forwards?
0:58:07 > 0:58:09Bloodhound needs a huge rocket to propel it forwards.
0:58:09 > 0:58:12Yeah, that's right! In fact, it's got two engines.
0:58:12 > 0:58:13It's got a jet engine here
0:58:13 > 0:58:15and that's going to take it to 300 miles an hour
0:58:15 > 0:58:18and then they're going to fire off the rocket down here
0:58:18 > 0:58:20which will take it to the full 1,000.
0:58:20 > 0:58:23- What do you think it's going to be like when that goes off?- Very noisy.
0:58:23 > 0:58:26- Very noisy.- Scary.- Yeah.
0:58:26 > 0:58:28But it'll only last for ten seconds,
0:58:28 > 0:58:31because once they've reached the land speed record,
0:58:31 > 0:58:34the rocket's going to cut out and it'll be time to slow down again.
0:58:56 > 0:59:00Subtitles by Red Bee Media Ltd