"Three. Two. One. Pull up."

- I'm experiencing 1.8gs right now, which means I weigh

about 1.8 times what I normally would.

I've been instructed to keep my head front and centre to avoid nausea.

But all this is about to change

because this is the European Space Agency's zero-g flight.

Those are students doing research.

This is Neil, who's here for my safety.

And we're about to go into freefall.

Whoa!

Whoa!

And here's the confusing thing.

We are still going up right now.

That camera is stabilised to the actual horizon,

and it's not until 10 seconds into our 20 second parabola,

into our manoeuvre, that we clip the apex and start heading

back down towards the ground.

And here we go, 1.8gs.

- In this special aircraft, we divide the three axes.

There is pitch, roll and thrust,

and each pilot flies one axis.

In every other aircraft, one pilot flies the three axes and

the other one manages the systems, talks on the radio, and so on.

To fly parabolas, we need to fly only one axis by one pilot.

We try to avoid any turbulence.

Any turbulence is a nightmare for us.

- The two control sticks, just like any plane,

are completely locked together, so they always move at the same time.

So one of the pilots is using

effectively elastic bands on either side of his stick

so that he doesn't affect the axis of the other pilot.

One of them does the pitch, the other one does the roll

whilst trying not to upset the pitch.

- In 1971, the Apollo 15 astronauts tested something on the moon:

The idea that all objects, no matter their weight,

fall at the same speed if there's no air.

They used a hammer and a feather, and they landed at the same time.

ASTRONAUT: "How about that?"

- But the weirdest thing is that if that astronaut had thrown that hammer,

it still would have been in free fall

from the moment it left his glove to the moment it hit the ground.

The only pull on it is from the gravity of the moon.

The maths work out the same

no matter what speed or direction it's going relative to us.

That's what we just did here.

If it sounds weird, sure, but we just proved it.

And we're about to prove it again.

- Every five parabolas or ten parabolas, we change

to maintain the best accuracy of the parabolas, especially

on the pitch axis because it's the most demanding flying technique.

So after five or ten parabolas, you are so tired and you

have to go on to another less demanding axis.

PILOT: "3, 2, 1, pull up."

- This parabolic manoeuvre isn't the normal kind of thing

that you do in an Airbus, and the software in this plane

hasn't been modified because to do so would be a huge effort to re-qualify it.

With the normal software, you have the normal alarm

saying, "This doesn't seem like a very good idea, guys,"

and one of the pilots that isn't too busy on the other two axes

is turning off the alarms that we don't need to worry about

and keeping track of the ones we might need to worry about.

PILOT: "Injection."

- So those pilots are keeping us on the exact path

that an object would take if you hurled it into the sky

at hundreds of kilometres per hour and there was no air.

They're giving us this little protective bubble of zero-g to fly around in.

There is no terminal velocity here, only the design limitations of the plane.

And we're going to hit those pretty soon, along with something else.

Because when you're descending this fast towards the ground,

the Earth approaches pretty quickly.

Thank you, Neil!

If you're a Masters or PhD student from an ESA member state,

and you want to be one of the people back there,

then have a look at the Fly Your Thesis program.

The link is in the description.

Thank you, Neil!

I got it, I got it, we're good.

And down.

Oooph.