Building underground habitats where
you get radiation shielding.
You could build an entire city underground.
Hey this is Warren Redlich. I wanted to talk to you today about
How SpaceX and The Boring Company will build colonies
on Mars and the Moon
in a way that protects humans
from radiation and the effects of low gravity.
Are you ready? Let's go!
While there are other things to worry about with
humans on Mars or the Moon,
making sure they have breathable air and warm enough.
We can solve those problems.
There's two critical things that we're concerned about
for the long term.
First is radiation.
If they're exposed to too much radiation on the Martian surface,
we know that the amount of radiation hitting the Martain surface is very high,
and is not good for human health.
It's worse than low-earth orbit
for astronauts because the earth's
magnetic field still protects humans in
low earth orbit. But you get them out to
the Martian surface and there's not much
to protect them from cosmic radiation and the Sun.
One thing we can do to protect people
from radiation is to go underground.
Elon Musk has talked about that.
Humans living on Mars or the Moon would probably spend
a large percentage of their time underground.
Getting good at digging tunnels
could be really helpful for Mars.
A lot of ice mining on Mars and mining in general
to get raw materials. Building underground
habitats where
you get radiation shielding.
You could build an entire city underground.
People are still going to want to go to the surface.
You can build a tremendous amount underground.
They would still be able to spend some time on the Martian surface.
You'd want to be careful to limit time
on the surface as necessary.
To minimize that radiation exposure.
The big question is how do you design
life underground on the Moon or on Mars.
I think I've got the answer to that.
The second thing is living with low gravity.
We've seen when astronauts are in low-earth orbit for extended
periods of time that their bodies suffer.
Our bodies adjust to not having gravity and they don't adjust in a
good way. We don't know for sure how
long term exposure to low gravity will affect humans.
There's a good chance that it will be harmful to
be in the 0.38g
gravity on Mars, which is 38% of
Earth's gravity. Or the 0.16g gravity on
the Moon, which is 16% of Earth's gravity.
We're pretty sure that that's
a good chance that will pose substantial risks
to the human condition. A lot of people have talked
about the same issues in space travel, coming
from Earth to go to Mars.
From Earth to go out into the solar system
One of the common proposals that we see
for astronauts traveling in space is some kind of
rotating space station.
That creates centrifugal force.
So your feet ... you're on the outside of a circle.
The circle's moving like this. Your feet are on the outside of the circle.
You can get in an argument about centrifugal vs. centripetal
But the centrifugal force pushes down on you
in the same way that gravity pushes down on you.
When the loop is too small
the gravity you feel at your feet is different (weaker) than the gravity you feel at your head
because your head is closer to the center of the circle
in a significant way. We can apply that
to the Martian colony and the Moon colony
in this way. We can build loops using Boring Company tunnel
boring machines to create big circles.
We would put trains or train cars
or something equivalent, running around in circles.
Traveling at a high enough speed
that it generates enough centrifugal force on the people inside
that they feel the equivalent of Earth gravity.
The way I picture the Mars loop or Moon loop happening
You start with the existing tunnel
boring machine technology that the
Boring Company is using.
A 4 meter diameter tunnel boring machine - they bore tunnels that are
a little bit less than 4 meters (13 feet) actually.
You take that in a loop that has a 200 meter radius or
400 meter diameter. It works out to being about
1250 meters around
or 1.25 km
0.8 miles around.
Goal is to generate enough centrifugal force to
compensate for the less gravity that you have on Mars.
It works out that you need to generate about
0.9g of gravity with the loop plus the 0.38g
of gravity from Mars. When you work out
the math that works about to about 1g.
To attain that 0.9g
you need to go about 2 RPM.
Two times around the circle per minute.
That works out to be about 90 miles per hour.
Interesting side note: It's a lot of volume
that you're going to create. The tunnel volume
works out to be about 15,000 cubic
meters. That's a lot of space.
In the end you're going to use the material
in a way I'll talk about at the end of this video.
You're going to start with one car. That one car will be about
10 meters long, about 3.8 meters
in diameter. And you create a floor
on the car
under which you would use for storage. Above
that you'd have your living space. About 3000 square feet
in one car.
We're talking about the early Mars colony or the early
Moon colony.
If the average person can get by
100 square feet - a 10-foot by 10-foot room (3 meters by 3 meters - 10 m^2).
In total you're able to support
30 people in just one car. The way I picture it
and I think the way Elon (Musk) pictures it
Most people would spend most of their time in this car in motion.
When it's at rest
the car would be resting on the bottom
of your tunnel. Straight up. And you'd have 0.38g
pushing down. Which is light for us humans.
As you get up to speed the car is going to go up
along the outside of the wall to nearly horizontal but not quite.
You'll have a total of
0.9g pushing ... it works out to 1g pushing
down on you at an angle.
You still have your storage space underneath. It simply rides up along the wall.
I don't think you need rails. You would use some kind of low
resistance surface for the tunnel and low resistance tires
or wheels running on the surface of the tunnel.
It just rides up as it speeds up, going from
straight up to up on its side.
90 miles an hour should not be very difficult to do.
The atmosphere inside the tunnel - not inside the car -
the car would be pressurized - but inside the tunnel
the Mars atmosphere is very thin. There's not a lot
of air to push out of the way. You have virtually zero wind resistance.
If you lose low rolling resistance tires and use a
smooth surface on the tunnel you should be able to minimize that.