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How Humans Will Colonize Mars

Mars: the red planet. It's been stoking the fires of our interplanetary imagination for generations yet we still haven't managed to visit our neighbor in person, let alone set up any long envisioned permanent colonies. Astrophysicist Paul Sutter explains the barriers complicating humanity's efforts to put roots down on Mars, how we might overcome them, and what it would look like to expand our footprint across the solar system.

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Released on 2/10/2022

Credits

Starring: Paul Sutter

Transcript

00:01
Mars is teasing us.
00:04
Humanity has been dreaming of landing
00:06
on the Red Planet for over a century.
00:08
And with the advent of space flight and moon landings,
00:11
it seems like it should be just right around the corner.
00:14
And these missions wouldn't just be
00:16
for scientific exploration, which would be super awesome,
00:19
'cause we would learn about the origins of life
00:22
and the formation of the solar system.
00:23
They would serve to set up a permanent human presence
00:27
on Mars, a colony on another world.
00:30
If only we could figure out how to do it.
00:33
[dramatic music]
00:36
Before we launch on our first mission to Mars,
00:39
let's look at the pros and cons
00:41
of living on the Red Planet.
00:45
Let's start with the cons, and frankly,
00:47
there are a lot of cons.
00:49
Mars has no air.
00:51
It has less than 1% of the air pressure of the Earth,
00:54
and what air there is, it's almost entirely carbon dioxide.
00:59
Mars has no liquid water.
01:01
There is water there, but it's locked up as ice,
01:04
either underneath the surface or in the polar ice caps.
01:07
We need liquid water to survive,
01:09
and this makes it just so much more challenging.
01:12
Next, Mars is constantly suffering bombardment
01:16
of solar radiation and cosmic rays.
01:18
These are high-energy particles that can break apart cells
01:22
and even snip DNA itself.
01:24
Without a thick atmosphere and without a magnetic field,
01:27
Mars is just exposed to this deadly radiation
01:31
and can increase cancer rates for any Martian colonists.
01:36
Mars is far from the Earth,
01:38
hundreds of millions of miles away.
01:41
It would be the most distant mission we've ever sent,
01:45
and it's also socially distant.
01:47
Martian colonists would be the furthest human beings
01:50
from Earth in, well, the entire solar system.
01:54
Mars has less gravity than the Earth does.
01:57
We don't know fully how to live and work
02:00
and maintain our health and fitness
02:02
in low-gravity environments.
02:03
Our hearts shrink, our muscles degrade,
02:05
our bones wither away.
02:07
We don't even know if fetuses in the womb
02:10
can grow straight spines without Earth's gravity.
02:14
To go along with that, Mars has about half
02:17
of the sunlight that Earth does.
02:19
And so anything that requires solar energy,
02:22
like solar power or photosynthesis,
02:24
is going to be so much less efficient.
02:27
Mars occasionally experiences global dust storms.
02:31
The dust on Mars has been blowing for billions of years,
02:34
and it's not like dust or sand you might find in a desert.
02:37
It's more like a fine talcum powder that gets everywhere
02:41
and occasionally coats the entire planet,
02:44
blocking out the sun for months on end.
02:47
Mars is also cold, really, really cold.
02:50
The average temperature
02:51
on Mars is negative 81 degrees Fahrenheit,
02:54
and it gets as low as negative 220 degrees Fahrenheit.
02:58
It's just a cold place.
03:00
It's colder than the coldest places on Earth.
03:02
And if that weren't enough, the soil on Mars is full
03:07
of toxic chemicals that have to be filtered out
03:10
before you can use it as soil to grow crops
03:13
or to breathe in or to just exist in.
03:16
These are all the cons.
03:17
What are some of the pros of going to Mars?
03:20
Why would we wanna do that?
03:21
Well, who doesn't like an adventure?
03:24
No, I'm serious, I'm serious.
03:26
Adventure and exploration has been a part of humanity.
03:30
It's in our DNA.
03:31
It's something that defines our species.
03:33
And going to Mars is simply the next step
03:35
in a journey that we've been on for tens
03:38
if not hundreds of thousands of years.
03:40
And hey, Mars can offer another home.
03:43
If something catastrophic were to happen to the Earth,
03:45
we'd have a plan B, a planet B, if you will.
03:48
And hey, going along with that,
03:50
Mars has lots of empty space free for the taking.
03:53
No one has a claim on Mars.
03:55
No one is already living there.
03:57
So it gives us a chance to colonize, to explore,
04:01
to build new cities and new civilizations
04:03
without eliminating existing ones.
04:06
And there's tons of science to be done on Mars.
04:10
Not just the history of the Red Planet,
04:12
but the origins of life.
04:14
Mars was once a potential home for life
04:16
with liquid water and a thick atmosphere,
04:18
but something stopped.
04:20
Understanding what happened on Mars
04:21
can help us understand the origins of life on the Earth.
04:24
And lastly, my favorite reason to go to Mars,
04:27
lots and lots of red.
04:30
If you're a fan of the color red,
04:31
well then, this planet is for you.
04:36
That was very satisfying.
04:37
Anyway, if Mars is so terrible,
04:41
why should we even bother going there?
04:43
Why don't we go to the moon?
04:45
The moon, it's literally next door.
04:47
It's only days away instead of months away.
04:50
There are some advantages to Mars over the moon.
04:54
For one, it's bigger, so it does have more gravity,
04:57
and it does have water.
04:59
It's frozen, but it still exists and is accessible.
05:03
Among all the worlds in the solar system,
05:06
Mars is the closest thing we have to Earth.
05:10
So to design our mission to Mars,
05:12
let's go to the chalkboard.
05:16
Let's take a look at what a single mission
05:18
to Mars would look like.
05:20
This is our solar system.
05:22
Well kind of, it's not exactly to scale.
05:25
But here in the center we have our happy little sun,
05:28
and here we have the orbit of the Earth
05:29
and the orbit of Mars.
05:31
If we want to get from Earth to Mars,
05:35
we have to do some very complicated orbital dynamics.
05:39
We need to rely on Newton.
05:41
Isaac, Isaac?
05:44
Okay, maybe he'll show up later.
05:45
Actually figuring out and plotting these missions is
05:49
incredibly difficult, and that's because the Earth
05:52
in its orbit, it's constantly moving, and so is Mars
05:55
at a different distance and a different speed.
05:57
So the most efficient way to get to Mars is
06:00
to wait for conjunctions, when our planets align.
06:04
To sketch out a mission here,
06:06
let's say we're on the Earth
06:09
and we wanna send a mission to Mars.
06:11
But when we're in conjunction,
06:13
by the time the mission actually gets to Mars,
06:15
it's not gonna be here, it's gonna be way up here.
06:19
So Mars is gonna be here in its orbit.
06:23
So our trajectory from Earth to Mars will look like this.
06:30
And with chemical rockets, that'll take about 180 days
06:33
in a weightless environment just to get to Mars.
06:37
Now, you get on Mars, you land, you poke around,
06:40
you scare all the Martians,
06:41
you do your normal Martian business there,
06:43
and you wanna get back to Earth.
06:45
Well, guess what?
06:46
You're not in conjunction anymore.
06:49
You have to wait.
06:50
You have to wait for the planets to align again.
06:54
So you have to wait on Mars as it continues its year
07:00
before everything lines up again.
07:04
And only then can you return to the Earth, and guess what?
07:08
It's another long trip.
07:09
When you launch from Mars here,
07:13
the Earth is not gonna be in conjunction anymore.
07:16
You have to travel another 180 days to intersect
07:21
and safely return to Earth.
07:25
This is one of the most energy-efficient missions to Mars,
07:29
and the entire mission duration is two years.
07:33
That's longer than any mission
07:36
we have ever had in space before.
07:38
And that's just a single mission.
07:40
To build a colony of permanent human presence,
07:43
we need tens, hundreds, thousands
07:45
of missions to the Red Planet.
07:47
We're gonna have to bring a lot of stuff.
07:50
I mean, oh boy, think about all the things
07:55
that you surround yourself with in your daily life.
07:58
Like air, we're gonna have to bring our own air to Mars
08:02
or figure out how to make it there.
08:04
We're gonna need communications gear
08:06
so we can talk to each other and call back to home.
08:09
We're gonna need a mode of transportation,
08:11
not just to get to Mars,
08:12
but to move around on Mars, to explore.
08:15
We're gonna need storage, we need like grain silos.
08:18
Is there grain on Mars?
08:19
No, there's not grain on Mars,
08:21
but we're gonna need silos for something eventually.
08:23
We need food, we're gonna have to either bring food
08:27
from Earth or figure out how to grow it on Martian soil.
08:30
We're gonna have to figure out how
08:31
to extract resources from Mars.
08:34
We need to turn that Martian regolith into walls
08:38
and ceilings and toilets and stuff, all sorts of stuff.
08:41
We need utilities, we need plumbing and electrical conduits.
08:45
We need ethernet cables and cell phone transmitters.
08:48
We need fuel to power everything.
08:51
We need water, and yeah, there's plenty of water,
08:54
but it's frozen, so we need to heat it up first.
08:57
We need habitats, we need a place to live.
09:00
We need a room and a dining room and maybe even a foyer.
09:04
But we need all this stuff.
09:06
We've begun to solve some of these challenges.
09:09
We've started thinking about how
09:11
to knock some of these items off the list
09:13
so that we can build up a permanent human presence.
09:16
And one very interesting idea relies on
09:19
something called the Sabatier process,
09:21
named after a French chemist.
09:23
Did I say the Newton process?
09:28
No, I didn't.
09:28
Isaac, you're late, you were supposed to be
09:30
on the other side, thank you.
09:31
What we're gonna talk later, okay?
09:34
Anyway, the Sabatier process, let me show you.
09:37
It's a very simple chemical reaction where
09:40
if you take carbon dioxide,
09:44
which Mars has plenty of carbon dioxide, that's for sure,
09:49
and you add some hydrogen, which we can take along with us,
09:54
it's a relatively easy to transport fuel,
09:57
put it under a lot of pressure at some high temperatures,
10:02
you get methane, which is a fuel,
10:08
and as a bonus, some water.
10:13
So one chemical reaction can transform something
10:17
that's already present on Mars
10:19
into a source of fuel and water.
10:22
That's not so bad.
10:23
This doesn't solve all the problems,
10:25
but it does start to chip away at them.
10:28
But to dig into the technology that we are developing today
10:31
to build a human colony on Mars,
10:33
we're gonna need to talk to an expert.
10:36
My name is Eric Berger.
10:37
I am the Senior Space Editor at Ars Technica
10:39
and author of a recent book called, Liftoff
10:42
about the origins of SpaceX.
10:43
So what are the next steps that we need in technology,
10:48
in engineering and understanding to enable a Mars mission?
10:51
Could we do it tomorrow if we wanted to?
10:54
You could do it tomorrow if you didn't mind
10:55
that the astronauts died.
10:57
But if you wanted them to live, we could not do it tomorrow.
11:01
When you think about it, really the first step
11:03
toward going to Mars is the transportation system.
11:06
You need a way to get four, six, eight
11:08
or more people off of the planet Earth
11:10
to survive a six-month journey to Mars
11:13
and then to get them safely down to the surface of Mars.
11:15
And then if you wanna bring 'em back,
11:16
you've gotta figure out how to launch a rocket from Mars,
11:18
rendezvous with maybe a spacecraft in Mars orbit
11:21
and then come back to Earth and then land on Earth.
11:23
We've never sent a really large spacecraft to Mars.
11:26
Obviously, the biggest one is about metric ton,
11:28
and we would need to land something in the order
11:30
of 20 to 30 tons on the surface of Mars.
11:32
So you really need
11:34
to solve the transportation system problem first.
11:36
And we don't have that, NASA doesn't have that.
11:39
No one really has that.
11:40
What about landing on Mars?
11:43
We've developed all sorts of interesting contraptions.
11:46
Like there was the giant bouncing ball.
11:49
There are these sky cranes.
11:51
How do we land a, like you said,
11:52
a multi-ton vehicle on the surface of Mars?
11:56
What kind of technology do we need to develop?
11:58
The key technology is propulsive landing.
12:01
We've never really done that on Earth.
12:03
When the space shuttle came back to Earth, it was a glider.
12:06
When our capsules come back to Earth,
12:07
they're under parachutes.
12:09
We launch under propulsion,
12:10
but we don't really land under propulsion.
12:12
Mars has a much thinner atmosphere, obviously.
12:14
And so to slow down such a large, massive spacecraft
12:18
coming to Mars, you need some kind
12:19
of propulsive landing technology,
12:21
and that's probably some kind of thruster.
12:23
But it's very much sort of theoretical
12:25
and not actually real.
12:26
In your estimation, and this is
12:29
just your personal Eric Berger take,
12:31
how long until the first human steps foot on Mars?
12:35
I'm 48 years old, Paul, and I'd love nothing more than
12:37
to see humans walk on Mars in my lifetime.
12:40
It's just a technological leap
12:42
with the existing rocket technology we have.
12:45
It's a half-trillion dollar mission at least.
12:48
And it requires decades sort of work to build up to it.
12:51
Realistically, I think even SpaceX,
12:54
we just talked about sending humans to Mars in the 2020s.
12:57
I don't see that as viable,
12:58
but within 10 to 15 years, maybe.
13:01
All right, all right.
13:03
Let's fast forward a couple decades into the future.
13:06
You're playing with your grandkids, you're watching the TV,
13:09
you're watching this Mars mission play out.
13:12
What does it look like step by step?
13:15
How many launches does it take
13:16
to get the required equipment into orbit and on Mars?
13:20
Just what does that whole scenario look like?
13:23
We went to the moon with the Saturn V rocket,
13:26
and that rocket was just big and burly enough
13:28
to carry everything we needed to set several tons down
13:32
on the surface of the moon
13:33
and get two astronauts there and back.
13:35
A single rocket ain't gonna do it for Mars.
13:37
So even if you have sort of the most powerful rocket
13:40
that NASA's building, which would be the Block 2 variant
13:43
of the SLS rocket, you'd probably need six to eight
13:46
of those launches to not just establish your ship
13:50
that's gonna go to Mars, but to fuel it.
13:52
That's kind of like why when Elon Musk or Jeff Bezos
13:55
or Relativity or these other companies,
13:57
their plans sort of incorporate reuse from the beginning,
14:00
because you're gonna have lots of launches to do this.
14:02
And if you're spending so much money
14:05
launching an expendable rocket,
14:06
you just can't afford to go anywhere.
14:07
Let's fast forward even a few more decades,
14:09
'cause we do wanna push the edge here,
14:11
and look at Mars colonization.
14:14
It's certainly plausible that the first missions
14:18
to Mars will be you'll go and you'll come back.
14:21
What would it take to set up a semi-permanent status
14:25
where there's rotating crews in and out,
14:27
like the International Space Station,
14:29
like our deep Antarctic research stations,
14:32
what kind of infrastructure would it take to get there?
14:35
I actually had an interesting conversation
14:37
with Elon Musk about this.
14:38
The question was, what would it take
14:40
to build a self-sustaining settlement
14:42
on the surface of Mars?
14:44
It would take one million metric tons of stuff,
14:48
propellant, the 3D printers, the stock for the 3D printers,
14:51
food, agriculture, domes, wherever you're gonna live,
14:55
all of it, to get to the point where you could have
14:58
all that on Mars and those people could then survive
15:01
without intervention from Earth.
15:02
So one million metric tons, if you think about that,
15:05
it takes a very large rocket
15:07
and a whole sort of sophisticated spacecraft.
15:10
The Curiosity mission was what,
15:12
a couple billion dollar mission to get to Mars?
15:14
And that Rover was one ton.
15:16
That's the challenge we're talking about,
15:18
sending one million Perseverances
15:20
or Curiosities worth of mass to Mars.
15:23
It's an enormous challenge.
15:24
And how many people would that support?
15:26
I would think that would be dozens or hundreds.
15:29
I mean, it would be like a growing, thriving colony.
15:31
But there are basic questions, right?
15:33
We don't know if humans can procreate in microgravity.
15:36
We don't know if they can procreate
15:37
in the one-third gravity on Mars.
15:39
How would humans evolve if they were living all
15:42
or most or all their lives on Mars?
15:43
These are great unanswered questions.
15:47
I'd love to answer them one day.
15:49
Is there a future for humanity on Mars?
15:53
I'm of the group of people who think
15:55
that the destiny of humans is to get out there
15:58
and live among the stars.
15:59
It's very clear that there are no planets
16:03
in the soar system or moons remotely close
16:05
to Earth in terms of the suitability for humans.
16:08
It is a Garden of Eden, literally.
16:10
And presumably, there are planet like Earth
16:12
or somewhat like Earth around other stars.
16:14
And we'll get there one day.
16:16
But to do that, we've gotta take the first step.
16:18
And I think if you look around the sources of Mars,
16:21
for all of its flaws, and there are many,
16:23
as you well know, offers the best bet.
16:26
Probably most importantly, it's fairly close.
16:29
Six months is a long time to get there, but that's doable.
16:31
It's not three years to a moon around Jupiter
16:34
or something like that, it's closer.
16:36
It's far from perfect, but you gotta start somewhere,
16:39
and that's probably the best place to start.
16:42
This was a delight of a conversation.
16:44
I really appreciate your time.
16:45
Thank you, Paul.
16:48
That's all short-term visits.
16:50
For long-term habitation, we have to face a massive problem.
16:54
How do we turn this into this?
16:59
This is a process called terraforming,
17:02
and it involves beefing up the Martian atmosphere.
17:06
But we need a lot of atmosphere.
17:08
We need at least 10 times the current Martian atmosphere
17:11
for water not to boil at body temperature.
17:14
And we need at least 20 times the pressure
17:16
to make it pleasant to walk around
17:18
on the surface without a suit.
17:20
So we need to bulk up that atmosphere, what do we got?
17:23
The best things we have on Mars are the water
17:25
and carbon dioxide locked up in the soil and at the poles.
17:29
But unfortunately, there isn't enough,
17:31
even if we liberated all of it
17:33
and put it all all into the atmosphere.
17:35
It would only raise the air pressure by like one or two
17:38
or maybe three times its current level, which isn't enough.
17:41
So we have to import an atmosphere from somewhere else.
17:44
We have to crash land comets from the outer solar system
17:47
onto the surface of Mars.
17:49
That kind of process is going to take generations,
17:53
and we have to fight an even bigger battle,
17:55
because Mars doesn't have a magnetic field.
17:58
The Earth's magnetic field protects the atmosphere
18:01
from the bombardment of solar radiation,
18:04
so we have to introduce an artificial magnetic field
18:07
around Mars in order to keep that atmosphere locked in.
18:11
For generations, Martian colonists are going to have
18:14
to live underground like some sort of Martian mole people.
18:18
Oh, and you got the note from my manager, right,
18:20
that I'm not wearing the mole costume?
18:22
Okay, got it.
18:23
That's long term.
18:25
Right now we're focused on stepping one foot on Mars
18:28
and then 10 and then a hundred,
18:29
slowly building up to have a permanent human presence.
18:33
There's no physics reason preventing us
18:36
from inhabiting Mars, it's a matter of technology
18:38
and engineering and patience, and most importantly, money.
18:42
But there's no reason why we can't eventually be on Mars.
18:47
Humanity will have a presence on Mars.
18:51
Well, I'm not going.