[♪ INTRO]
Wow!
Look at all that smoke.
Yeah, that fiery tail is amazing.
Oh, hey there!
Squeaks and I were just re-watching 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 5th 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.
Oh, 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 far away video, but rockets are huge.
And it’s not surprising to hear that something that big weighs a lot!
It tipped the scale at more than 530,000 kilograms, that’s like 100 elephants.
Oh, 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 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 of 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.
Aw, 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?
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.
Ooo, yeah, good question!
It did look like the rocket broke in mid-air, huh?
Well, it turns out 100 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 you need to know is that the farther away
the rocket gets from Earth, the weaker the pull of its 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.
Let’s find another rocket launch to watch, Squeaks, what do you say?
Thanks for joining us!
If you want to keep learning and having fun with me, Squeaks, Mister Brown,
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and we'll see you next time here at The Fort!