The rocket equation.
It's a beautiful thing.
No astronaut launches
for space
with their fingers crossed.
That's not how we
deal with risk.
What I learned from 21
years as an astronaut
is that the more you
know, the less you fear.
The reason I wanted to
do this MasterClass
is to share the hidden
depths of purpose that
are behind space exploration.
When the clock hits zero,
start focusing and thinking
of nothing else but the
moment that you're in.
Study every system on
a spaceship and then
boil it down to what
I call a one pager.
You've got to be able to solve
your problems in one breath.
You have to push
your lungs forward
through the drag
of the atmosphere.
Crushed into your chair – 
you're like a leaf
in a hurricane.
The reason is one
half rho v squared s.
Sixteen times the speed of
sound. As you accelerate
harder and harder, that
light blue Florida sky
starts to get darker and darker.
And then suddenly, black–
and the engines shut off
and you're weightless.
Turn the handle
and open the hatch.
You pull yourself
out into the universe
and now suddenly, when
you move your knees,
you can feel the searing
heat of the sun on one side
and the incredibly
cold emptiness of space
on the other.
When you're no
longer earthlings,
how do you navigate?
You can use the stars.
You can actually see how that
place where you were raised
fits into the overall
complexity and reality
of the solar system.
You start to unavoidably
wonder, are we
alone in the universe or not?
Our technology is
just good enough now
that some of you taking
this MasterClass
are going to fly in space.
Reusable rocket
ships give us access
to explore like we've
never had before.
It will be a great moment of
introspection for humanity
if you're the person who
finds that one little
fossilized flower on Mars.
I'm Chris Hadfield, and
this is my MasterClass.
