Hey there, Squeaks.
What are you working on?
Oh, I see.
You're looking up all the things you can think of that can fly.
Airplanes, helicopters.
Wow, there sure are a lot of them.
Oh, great question.
Squeaks wants to know just how all these things can stay up in the air.
Well, let's start with the first thing on your list, airplanes.
Here's how airplanes can fly.
Air.
And.
Oh, hey there!
Squeaks and I were just packing for our trip.
We're going to a museum together!
It's going to be Squeaks' first time ever on an airplane, but he's a little nervous.
You remember what to expect, buddy?
We'll put our things away, buckle our seatbelts, and then we'll take off!
You're right, the airplane isn't going to flap its wings like a bird.
But the airplane does need its wings to fly.
When an airplane is ready to take off, the pilot turns on the engines.
The engines push the airplane forward along the ground on little wheels, going faster and faster and faster.
The push, or force, from the engines is called thrust.
Thrust is what will help to move the airplane forward on the ground, and eventually into the air.
The thrust force is also going to be really important for creating another special push or force that will push the plane up into the air.
You see, the wings do something amazing as they move through the air.
Air doesn't seem like very much to us.
We can't see it, and most of the time, we don't really feel it.
But air can push on things.
It pushes down on us all the time.
That's called air pressure.
But air pressure doesn't only push down.
The shape of an airplane wing can make air push it up instead.
Here, let's check out a picture of an airplane to help show you.
Here are the wings.
And these big round things are the engines.
You can see the wheels that the plane uses on the ground, too.
But let's look at the wings of this airplane.
What do you notice about their shape?
Oh yes, great observation!
This airplane's wings are kind of flat on the underside, but the top is a little bit rounded and curved.
Because of an airplane wing's unique shape, air moves differently above and below it.
As the airplane moves forward from thrust,
The air has to move from the front of the wing to the back as the airplane moves forward.
But in order to get over the rounded top edge of the wings, the air has to move faster than it does to go underneath the flat bottom of the wing.
Because the air underneath the wing isn't having to go as fast, it is able to put more of a push on the wings than the air above the wing.
This pressure pushes on the airplane wings and it pushes more up from the bottom, making the plane go.
You're right!
Up!
The push from the slower air under the wings is another force called lift.
Lift does exactly what it sounds like.
It lifts the airplane wings up into the air, bringing the whole airplane up up.
The airplane won't be lifted up forever Squeaks.
Pilots control how high up the airplane is lifted and whether it turns left, right or back down toward the ground using the engines and special panels on the wings and tail of the airplane.
Those panels can change the way air moves around the wings, so they change the way it pushes on them too.
Depending on where you sit in the airplane, you might even be able to see some of these special wing panels move as we take off and fly.
I'm so glad that you're excited to watch the airplane work, Squeaks!
And I'm glad that this is making you feel better about your first airplane ride.
You know, sometimes just understanding something can make it a lot less scary.
Now that you know how the shape of the wings and the thrust from the engines help an airplane to take off and fly, this trip isn't going to be just about traveling.
It's now a great way to observe science and engineering in action!
Yep, airplanes have to go really fast to stay in the air, but not everything flies the same way.
How about a really fun way to spend a summer afternoon, like in a hot air balloon?
While you're looking up some pictures, let's learn how hot air balloons fly.
Sometimes on a nice, clear day, we can see something special in the sky.
A hot air balloon.
Have you ever seen one?
Have you ever wondered how a hot air balloon works?
How does it get up there?
And how does it stay up there?
Well, it's all about the air.
There's nothing special inside the balloon that makes it float.
It's just the same air that we're breathing right now.
So how does that keep the balloon up there?
Well, even though you can't see it, Air isn't nothing.
It's something.
Air is made of matter.
Anything that you can touch or feel, or that takes up space, is made of matter.
So air is made of matter, just like water is made of matter.
And so are the clothes you're wearing and the food you eat.
Even your body is made of matter.
So what kind of stuff is matter?
Made of tiny things called molecules that are way too small to see, but they're there.
So both inside and outside the balloon, there are many molecules of air moving around and taking up space.
But you know what's fun about molecules?
When they heat up, they start to move differently.
That's right.
When something gets warm, the molecules that it's made of start to move around faster, bouncing around and spreading out.
And that's the important part.
They spread out.
So let's think about how that would happen in a hot air balloon.
When the balloon is on the ground and ready to go, it has some air inside it.
And that air is the same temperature as the air outside of the balloon.
So the air molecules are all moving around at the same speed and are just as far apart from each other, both inside and outside of the balloon.
But then, the balloon pilot makes the air inside the hot air balloon hotter!
You see, these balloons don't have engines like airplanes do.
They have big heaters that send flames up into the balloon.
So when the pilot turns on the flames, it heats up the air inside it.
That makes the molecules of air start bouncing around inside and they start to get further and further apart from each other.
As these molecules spread out, they start to fill up the balloon even more.
And when those molecules of air inside the balloon start to take up more space, we say that the air becomes less dense.
Soon, the air inside the balloon becomes less dense than the air outside.
Now, maybe you remember when we talked about why some things float and other things sink.
We learned that things that are less dense than water will float to the top, while things that are more dense will sink.
And the same is true with our balloon.
The hot air inside the balloon is less dense than the cool air outside, so the balloon can float up.
In fact, warm air always floats up.
Have you ever noticed that in the winter, when you have the heater on, the downstairs of your house is usually a lot cooler than the upstairs?
That's because the warm air in your house is rising to the top.
So in a hot air balloon, the hot, less dense air inside the balloon rises up on top of the cooler, denser air outside.
And that makes the balloon… rise.
Now, how does the balloon get back down?
Well, the pilot opens a flap at the top of the balloon that lets the hot air out.
As the balloon fills with cooler, denser air, it begins to sink gently back down to the ground.
It may be hard to believe that something so big can be carried by little molecules we can't even see, but that's what makes hot air balloons and science so amazing.
Squeak says he'd love to try a hot air balloon someday. if he could get over his fear of heights.
Let's see, what's the next flying machine you were looking at?
Ooh, helicopters.
I know about one especially cool helicopter, one that flew on another planet, the planet Mars.
Let's ask Mr. Brown to help us learn about that one.
Hi there!
Squeaks and I are so excited!
We've been learning about Ingenuity, a special machine that scientists at NASA put on Mars.
NASA has put a few different machines, called rovers, on Mars before.
A rover is a kind of vehicle that's made to drive on a different world.
And the ones on Mars have been driving all over the ground to explore, take pictures and send information back to Earth.
But Ingenuity works a bit differently, because it doesn't drive.
It's the first machine built to fly around the surface of Mars!
You're right, Squeaks!
Flying gives scientists a totally different way of looking at the planet.
And since ingenuity works so well, space engineers will probably build more flying machines to explore Mars.
Oh, of course!
I'd be happy to answer your question about ingenuity.
Great question!
A lot of the flying machines we have on Earth are airplanes.
But Ingenuity isn't a plane.
It's a helicopter!
Helicopters fly a bit differently than planes, or even birds.
Exactly!
Both birds and planes use their wings to fly.
But helicopters do something different.
They have spinning blades on top, which act kind of like a giant fan to push the air and fly.
A helicopter's blades are angled up just a bit, so as they spin they push the air down, which lets the helicopter go up.
Now, that all works great here on Earth.
But there's a big problem with flying anything around Mars. there isn't much air to push against.
The surface of Mars has way less air than the surface of Earth.
Other planets are all really different from Earth.
Earth is the only one that we know about that has lots of great air for us to breathe and for planes and helicopters to fly.
But Mars has other cool things like huge dust, storms and mountains that are bigger than any mountain on Earth.
So engineers at NASA's Jet Propulsion Laboratory had to work really hard to design a helicopter that could fly on a planet that is so different from Earth.
They tried out lots of different designs.
That's because problems can have lots of different solutions.
And engineers like to test different solutions to see which ones work best.
Like, which helicopter design flies best or is easiest to send all the way to Mars?
And they came up with ingenuity.
One thing that makes it different from helicopters on Earth is that it's super lightweight, so there's less to lift up in the first place.
And it has really long blades that spin really really fast to push what little air there is, as much as possible.
It does sound like a fun project, doesn't it?
Now that you mention it, I have a fun challenge that can help us work and think like space engineers.
We can build a model helicopter.
We use models to help us understand or explain something about the world.
So a model helicopter could be a simple version that shows us something about how real ones work.
You can build one, too!
All you'll need are scissors paper, a printed PDF template from NASA, which we've linked in the description, a stopwatch or clock to time your copter and a grown-up helper.
First, we'll cut along the dotted lines on this template.
Then, we'll fold along the bolded lines here to make our own paper helicopter model.
Because it's a model, it should work similarly to how a real helicopter works.
Now a real helicopter, like Ingenuity, has an engine to spin its blades really really fast, so the helicopter can stay in the air.
Our model doesn't have an engine, but the paper blades will spin like real helicopter blades if we drop our model from up high.
Like if a grown-up drops it from up on top of a stepladder or chair.
The spinning blades should push the air under the model and help slow down our model's fall.
I want to make sure that this works, so let's compare it to the same cutout, but with all of the blades pointing up, so they can't push the air as well.
Alright, Squeaks.
Let's drop these from up high and see if the blades help our model to stay in the air longer than the comparison cutout.
Okay, here we go.
First one.
And second one.
Whoa!
That worked pretty well.
What did you notice about our model squeaks.
The model with the blades stretched out spun better and took longer to reach the ground.
This is a pretty good first design, but I wonder if there's something we could do to make our model stay up longer.
The engineers who built Ingenuity had to try many different designs before they found the best one, so we can do the same with our model.
What ideas do you have, Squeaks?
Oh, we could try making a model with longer blades, like the long blades Ingenuity has.
Maybe that would help our model to push more air.
We can even use our clock to help us time how long each design we try is able to stay in the air.
We can test lots of changes to our design this way.
What other things could we try?
Ooh, good idea!
Ingenuity is lighter than other helicopters, so maybe we can try a thinner kind of paper like tissue paper.
And we could try heavier paper, too!
I was thinking we could try different angles for the blades to see which one catches the air the best.
You're right, Squeaks!
As good engineers, we'll need to try lots of different designs to find the best one.
It does sound like a fun afternoon.
Let's get testing.
Oh, interesting question.
Squeaks wants to know if the helicopter flew all the way to Mars.
It flew all the way there, but not by itself.
Instead, it was carried most of the way there by a rocket.
Hey, that's one of the pictures of flying machines you're looking at too.
Rockets are some of the biggest, most amazing flying machines ever.
Let's learn a little bit more about what they can do.
Wow, look at all that smoke.
Yeah, that fiery tail is amazing!
Oh, hey there!
Squeaks and I were just rewatching a video of the Atlas V rocket that took the Perseverance rover to Mars.
A rover is a vehicle that's designed to explore another world, and Perseverance is the fifth one to go to Mars.
We've been thinking a lot about Perseverance and Mars in general ever since we watched the rover land on the planet earlier this year.
That was so exciting!
But launches are exciting, too!
The countdown, the burst of flame, and liftoff!
I never, ever get tired of watching them!
And the rocket itself is so cool!
I think they sort of look like pencils, mostly round on the bottom and pointy at the top.
That's a great question, Squeaks!
Squeaks was wondering where in the rocket the rover was.
It was towards the top, in a part called the spacecraft.
So it was safely tucked away from all the fire and smoke that came out of the engines at the bottom of the rocket.
It's sometimes hard to appreciate on a faraway video, but rockets are huge!
And it's not surprising to hear that something that big weighs a lot.
It tipped the scales at more than 530,000 kilograms.
That's like a hundred elephants!
That's another great question, Squeaks!
He wants to know, how does something so big and heavy get off the ground and all the way into space?
Well, essentially, they push off.
That's what all of the fire and smoke is.
Beneath the rocket is the launch pad.
It's made of concrete and is super strong.
When it's time for launch, the rocket engines mix and heat up two things called hydrogen and oxygen.
They're both all around us in the air all the time, even though we can't see them.
Ooh, good thinking, Squeaks!
We do use oxygen in a special way.
We breathe it.
But when oxygen and hydrogen mix together and they get really hot, they combine and form this really huge cloud that rushes out the end of the engine super fast.
And it pushes against the launch pad hard.
Really hard.
Do you remember what we call something that pushes or pulls?
A force, you're right!
This huge push is a huge force.
And what happens because of the force or the effect of the force, is that the rocket lifts off the ground.
Forces are all around us, and we see and feel their effects all the time.
For example, a force called gravity keeps you, me, and everything around us on the ground.
If gravity didn't exist, there'd be nothing to keep us on the ground.
So even a tiny hop could send us off into space.
So thankfully, Earth's gravity is always pulling on us.
Oh, that's fair enough.
We usually don't feel like we're being pulled on by the force of gravity, but that's just because we're used to it.
And there's a simple way to feel the force of gravity.
All we have to do is jump.
Ready?
Jump!
When we jump, we make a force because we're pushing down on the ground with our feet and that makes us go up.
But we didn't keep going up, did we?
That's because once our feet left the ground, gravity took over and pulled us back to Earth.
A rocket is basically the same idea as us jumping into the air, but on a much bigger scale.
Good question, it did look like the rocket broke in midair, huh?
Well, it turns out, a hundred elephants' worth of rocket is actually too much to push all the way to Mars.
So as the Atlas rocket moved away from the ground, it broke apart into a few big pieces called stages.
Each stage has its own engine and its own fuel.
And when a stage uses up all its fuel, it drops its empty compartments to keep the rocket light and easy to fly.
Eventually, all the stages fall away, leaving just the spacecraft.
The other thing that you need to know is that the farther away the rocket gets from Earth, the weaker the pull of Earth's gravity gets.
So once the rocket gets the spacecraft far enough away, it can use much smaller engines to finish the trip.
Not all rocket engines work exactly this way, but they all make a force to help the rocket leave Earth and get into space.
OK, let's find another rocket launch to watch.
What do you say?
Yeah, rockets sure are cool.
But I can think of one other flying thing that's even more amazing.
And you haven't looked up any pictures of that yet.
Well, you have lots of amazing machines made by humans on your list.
But I can think of something else.
Living things that can fly.
Things like birds, insects, and me.
Yeah, it is pretty cool that I can fly.
It's all because of my amazing wings.
Here's how they work.
Hey there, everyone!
Squeaks was just telling me about the big trip he's planning with Jesse.
It'll be his first time flying on an airplane.
He's pretty nervous.
It's natural to be anxious before a big event, but we've been helping Squeaks find ways to feel less scared.
I think it's great that you're learning all about how planes and flying work to help you feel less nervous about your first plane ride.
But there are a lot more things on planet Earth that fly than just airplanes.
Can you think of some?
Huh.
Sam the Bat?
Dino?
Bill and Webb?
We do actually have a lot of friends with wings, don't we?
Different kinds of animals like bugs, birds, and bats all have wings.
And have you ever watched all those different kinds of animals fly?
They all look a little different when they fly, don't they?
Let's check out some of the different ways animals use flight to get their bodies from one place to another.
This is a really big bird called an albatross.
They spend a lot of time soaring above the ocean.
What do you notice about its wings, Squeaks?
I think they look very long and skinny.
A little like airplane wings, don't you think?
Those big wings help them fly long distances to find the food they need.
A little bit like the jet plane you're going to fly on.
These birds use their wings to move their bodies long distances.
They travel a long way and for a long time because they're looking for food.
Their favorite foods, like squid and animals called krill, might be far apart on the surface of the ocean.
So the albatross has to move its body a long way to find the best food.
In fact, one kind of albatross can fly around the whole world in just six weeks!
What other kinds of flying things can you think of?
Oh, yes, great idea!
Bees have wings too, although they're very different from an albatross's wings.
What do you notice about the shape or structure of a bee's wings?
Yes, the wings of a bee are more short and stubby.
And let's watch it fly.
The albatross flies a long way, while the bee makes lots of stops, jumping from flower to flower.
The pollen and nectar in the flower are the bee's main food, and it has to visit lots of flowers.
So rather than traveling a long way, it might visit many flowers that are close together.
If the albatross flies a long way like a jumbo jet, the bee is like a city bus making lots of stops.
They have to move their bodies in different ways to get food, so they have different kinds of wings to help them do that.
And what about penguin squeaks?
Have you ever seen one fly?
I haven't either, but they are a bird, and they do have wings.
They just don't use their wings to fly in the air.
Penguins use their wings to move themselves through the water.
Scientists think it's a lot like other birds flying through the air, since the penguins use their wings in a similar way.
Let's look at a penguin's wings.
See how their wings are flat, almost like the paddle of a boat?
That shape, or structure, is good at moving the penguin through the water.
It flaps its wings to swim and that moves the penguin through the water, just like other birds flap their wings to move through the air.
Why do you think penguins need to fly in the water instead of air, Squeaks?
Yes!
The penguin's food is fish, so the penguins have to move their bodies underwater to catch their food.
Wow, Squeaks.
There sure are a lot of different creatures that use their wings to move their bodies where they need to go, aren't there?
Oh, you want to know what it feels like to fly?
Well, it feels incredible.
Maybe we can look into building you a pair of wings.
Well, let's work on getting you into the hot air balloon first.
How about that?
What do you think it would feel like if you could fly?
And remember, if you want to keep on learning with me, Squeaks and all of our friends, be sure to subscribe and we'll see you next time here at the fort.
Bye.
