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>> Hello and welcome to
the International Space Station.
My name is Shane Kimbrough,
and I'm an astronaut
living and working here
215 miles above the Earth.
Today we're going to be learning
about what a simple machine is
and exploring the different ways
we're using simple machines
up here in low Earth orbit.
A simple machine is an object
that helps us to easily
accomplish a task
by changing the direction
or amount of a force.
There are six different types
of simple machines:
a screw, inclined plane,
wedge, lever, wheel and axle,
and pulley.
When we combine
two or more of these
simple machines together,
they are called
compound machines.
Let's dive into the purpose
of each of these devices
and how we are using them
up here on the station.
A screw is a simple machine
that helps to fasten
two objects together.
Up here we use
a variety of screws
in order to keep
our station intact,
especially as we deal with
microgravity causing objects
to drift around.
Here's an example of a screw
that we may use on a spacewalk.
And inclined planes
are a broad range
of simple machines
that use an angled plane
to accomplish different tasks.
Down on Earth,
you used inclined planes
to move things easily.
But here in microgravity,
we don't need inclined planes
to help us move objects.
If you look closely
at a screw,
you will see that it is made up
of a rod with an inclined plane
that spirals around it.
this inclined plane
helps the screw
to fasten to another object.
Another simple machine
using inclined planes
to accomplish something
is a wedge.
A wedge consists
of two inclined planes
combined to split
or separate objects.
We often use wedges
to cut objects here on
the International Space Station.
The wheel and axle
is exactly what it sounds like.
A wheel is attached to an axle,
helping it to rotate
and move easily
without friction.
we sometimes use wheels
to help move items that
we need to be able to travel
without floating away.
An example of this would be
the wheels on our crew equipment
and translation aid cart.
It is attached to a track
using wheel and axles
for movement.
So we are able to use it
on our spacewalks
without the possibility
of it drifting off.
I mentioned
compound machines before,
and our advanced resistive
exercise device, or ARED,
is a great example of that.
It combines the simple machines,
levers and pulleys,
to help us maintain muscle
and bone density in micro G.
Levers use a surface
situated on a fulcrum,
or pivoting point,
to move an object.
Pulleys are simple machines
that use a wheel and axle
to change the direction
of an object.
The pulleys inside ARED
allow us to set the level
of resistance for our workouts.
Thank you for learning about
simple machines with me today.
Now I'm gonna send you
back to Earth to design
a compound machine you think
we could use up here on
the International Space Station.
See you next time.
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