The challenges of an interplanetary architect | Xavier De Kestelier | TEDxLeuven

The stars have always spoken to our imagination. The Moon and Mars are just two of the destinations that make many of us look up and dream. Some even want to move there permanently... In this fascinating talk, Xavier De Kestelier - a lunar and Mars base architect - explores how we can build structures that can withstand the extreme conditions of other planets and can still provide a home to our astronauts.

Xavier De Kestelier, architect and visiting Professor at Ghent University and Adjunct Professor at Syracuse University is joint head of Foster+ Partners’ Specialist Modelling Group (SMG), the architecture practice’s multi-disciplinary research and development group. His team has been exploring the possibilities of large scale 3D printing to construct lunar habitations.
Addressing the challenges of transporting materials to the moon, he studies the use of lunar soil, known as regolith, as building matter.

This talk was given at a TEDx event using the TED conference format but independently organized by a local community. Learn more at http://ted.com/tedx

I must have been about twelve years old

when my dad took me
to an exhibition on space,

not far from here, in Brussels.

The year was about - I think it was 1988,
so it was the end of the Cold War.

There was a bit of an upmanship going on
between the Americans and the Russians

bringing bits to that exhibition.

NASA brought a big blown-up space shuttle,

but the Russians, they brought
a MIR space station.

It was actually the training module,
you could go inside and check it all out.

It was the real thing,

where the buttons and the wires were,

where the astronauts were eating,
where they were working.

And when I came home, first thing I did,
I started drawing spaceships.

These weren't science fiction spaceships.

No,

they were actually technical drawings,

they were cutaway sections
of what a structure would be made out of,

where the wires were,
where the screws were.

So, fortunately,

I didn't become a space engineer,
but I did become an architect.

So, these are some of the projects
I have been involved with

over the last decade and a half.

All these projects are quite different,
quite different shapes,

and it is because they are built
in different environments

they have different constraints.

And I think, design
becomes really interesting

when you get really harsh constraints.

Now, these projects have been
all over the world, right?

A few years ago, this map
wasn't good enough, it was too small.

We had to add this one
because we were going to do

a project on the Moon
for the European Space Agency.

They asked us to design a Moon habitat,

and one on Mars with NASA -

the competition to look at
a habitation on Mars.

Whenever you go
to another place as an architect

and try to design something,

you look at the local architecture,
the precedents that are there.

On the Moon, that is
kind of difficult, of course,

because there is only this,
there is only the Apollo missions.

The last time we went there,
I wasn't even born yet.

And we only spent about three days there.

For me, that is kind of a long
camping trip, isn't it,

but a rather expensive one.

The tricky thing,

when you are going to build
on another planet or on the Moon,

is how to get it there.

First of all, to get a kilogram,

for example, to the Moon surface,

it will cost about 200,000 dollars.

Very expensive.

So, you want to keep it very light.

Second: space. Space is limited.

This is the Ariane 5 rocket.

The space you have there is about
four and a half meters by seven meters,

not that much.

So, it needs to be an architectural system

that is both compact,
or compactible, and light.

I think I've got one right here.

It is very compact and it is very light.

And actually, this is one I made earlier.

There's one problem with it,

that inflatables are quite fragile,

they need to be protected,

specifically when you go
to a very harsh environment like the Moon.

Look at it like this.

The temperature difference on a Moon base
could be anything up to 200 degrees.

On one side of the base
it could be a 100 degrees Celsius,

and on the other side
it could be minus 100 degrees.

You need to protect yourself from that.

The Moon also does not have
any magnetic fields,

which means that any radiation -

solar radiation, cosmic radiation -
will hit the surface.

We need to protect ourselves
from that as well,

protect the astronauts from that.

And then third,
but definitely not last,

the Moon doesn't have any atmosphere,

which means any meteorites coming into it

will not get burned up
and will hit the surface.

That's why the Moon is full of craters.

Again, we need to protect
the astronauts from that.

So what kind of structure do we need?

The best thing is really a cave,
because a cave has a lot of mass.

And we need mass, we need mass
to protect ourselves from temperatures,

from radiation, and from meteorites.

So, this is how we solved it.

We have indeed the blue part,
as you can see,

that is an inflatable for a Moon base.

It gives a lot of living space
and a lot of lab space.

And attached to it, you have a cylinder,

and that has all
the support structures in it,

all the life support and also the airlock.

And on the top of that,
we have a structure -

that domed structure, that protects
ourselves, has a lot of mass in it.

Where do we get this material from?

Are we going to bring concrete
and cement from Earth to the Moon?

Well, of course not, because it is
way too heavy, it's too expensive.

We are going to use local materials.

Local materials is something
we do on Earth as well.

Wherever we build,
in whatever country we build,

we always look at:
what are the local materials here?

The problem with the Moon is:
what are the local materials?

Well, there is not that many,
we actually have one.

It is moon dust,

or, fancy or scientific name,
"regolith," Moon regolith.

Great thing is it is everywhere, right?

The surface is covered with it -

there's about 20 centimeters
up to a few meters everywhere.

But how are we going to build with it?

Well, we are going to use a 3D printer.

Whenever I ask any of you
what a 3D printer is,

you probably think
of something about this size,

and it would print things
that are about this size.

Of course, we won't bring
a massive 3D printer to the Moon

to print a Moon base.

I am going to use a much smaller device,
something like this one here.

This is a small device, a small
robot rover that has a little scoop,

and it brings the regolith to the dome,

and then it lays down
a thin layer of regolith.

And then you will have the robot
solidify it layer by layer

until it creates,
after a few months, the full base.

You might have noticed

that it is quite a particular
structure that we are printing.

I have got a little example here.

We call this a closed-cell foam structure.

Looks quite natural.

The reason we are using this
as a part of that shell structure

is that we only need
to solidify certain parts,

which means we have to bring
less binder from Earth,

and it becomes much lighter.

This is really not just,

let's say, paper architecture, right?

We wanted to go and test this out,
so we went to Italy with this company,

and we tried out to print
a mock-up, the real size.

We are also using, well, not moon dust,
because that would be --

first of all, there's not a lot
of moon dust to do this with.

We used a moon dust simulant.

This is dust that has chemically
the same consistency as moon dust.

And we printed it layer by layer.

But you might notice
that the block we printed here

is about one and a half tons heavy

and has a much thicker structure
than the one I have here.

Well, this is because this one
I designed for the Moon,

which has one sixth
of the gravity of Earth.

And this one here, of course,
is printed on Earth.

So it is much thicker.

That approach of designing
something and then covering it

with a protective dome,
we also did for our Mars project.

You see here three domes,
and you see the printers

printing these dome structures.

Now, there is a big difference
between Mars and Moon.

Let me explain it.

This diagram shows you, to scale,
the size of Earth and the Moon

and the real distance,
about 400 thousand kilometers.

If we then go to Mars -

The distance from Mars to Earth,
and this picture here is taken

by the rover on Mars, Curiosity,
looking back at Earth.

You can see the little
speckle there - that is the Earth,

400 million kilometers away.

The problem with that distance is

that it is a thousand times the distance
Earth-Moon, pretty far away,

but there is no direct radio contact

with, for example, the Curiosity rover.

So I cannot teleoperate it from Earth.

I can't say, "Mars rover, go left!"

because that signal will take
twenty minutes to get to Mars,

then the rover might go left,

and then it will take another 20 minutes

before it can tell me,
"Oh, yeah, I went left."

So, stuff, rovers and robots

are going to have to work autonomously.

The other issue with it is that
missions to Mars are highly risky.

We have only seen it a few weeks ago.

What if half of the mission
doesn't arrive at Mars, what do we do?

Instead of building just one
or two rovers, like we did on the Moon,

we're going to build hundreds of them.

It's a bit like a termites mount,

I would take half of the colony
of the termites away,

they would still be able
to build the mount.

It might take a little bit longer.

The same here: if half of our rovers
or robots don't arrive,

well, it will take a bit longer,
but we'll still be able to do it.

Here we even have three different robots.

In the back, you see the digger,
it is really good at digging regolith.

Then, we have the transporter,

great at taking regolith
and bringing it to the structure.

And the last ones -

the little ones with little legs-

what they do is
they sit on a layer of regolith,

microwave it together,

and layer by layer
create that dome structure.

We also wanted to try that out,

so we went out on a workshop,
and we created

our own swarm of robots.

Here we go.

We built ten of those -
it's a small swarm -

and we took six tons of sand,
and we tried out how these little robots

would actually be able to move
sand around - Earth sand in this case.

They were not teleoperated, right?

Nobody was telling them
to go left, go right,

or giving them a pre-described path.

No, they were given a task:
move sand from this area to that area.

And if they came
across an obstacle, like a rock,

they had to sort it out themselves,
or they came across another robot

that'd be able to make decisions.

Or even if half of them fell out,
the batteries died,

they still had to be able
to finish that task.

Now, I talked about redundancy.

But that was not only with the robots,
it was also with the habitat.

On the Mars project,
we decided to do three domes.

Because if one didn't arrive,
the other two could still form a base.

And that was mainly
because each of the domes

actually has a life support system
built in the floor,

so they can work independently.

It was also in this project that we
started to think a little bit more:

"How is it for an astronaut
or cosmonaut to live in a base?"

Again, look at precedence.

Here is the International Space Station.

I don't know about you,
but I wouldn't really want to live

in that space for six months or a year.

It is really living inside a machine.

Well, maybe science fiction gives us
better clues, right, in the movie "Moon."

Often in science fiction you'll see
very sleek clinical spaces

and also loads of corridors,

in science fiction,
loads of corridors, all the time.

And knowing what we know now,

what we don't have in space is space.

So, it may be not
such a good example either.

But I think this is a good example.

This is Halley VI,
the British Antarctic Survey,

it is the British base in the Antarctic.

What is interesting here is that
the base is in a very harsh climate,

especially in winter.

On top of that, it is very isolated.

It is actually not possible
to get evacuated from Halley VI

during winter months.

It's easier to get evacuated from the ISS,
International Space Station,

than it is from Halley VI.

So, we went and spoke to people there -

well, not there, the ones
that were in London,

who stayed there earlier -

and had long conversations
about it with them.

A lot of things came up, and one
of the things they mentioned a lot was:

"Well, you know, imagine,
we live and also work there.

So, we live and work in the same place;
it's like living in your own office."

How does that work?

And they said, they really
missed tactile things.

Tactile, what does that mean?

"Look at what we did," they said.

"We put up, we took some crates,

some packaging crates
that we had laying around,

some plywoods, put it on the wall,

put some rope around,
and we kind of built this thing.

So, it felt a little bit more homey,
a bit more tactile."

And tactile was the word
they not only used for the wood surfaces,

they also said, "Oh, we're also
growing our own lettuce now,

because all the food we have is great,
it is frozen or is in tins,

but what we miss is just
something crunchy, something tactile."

So, we took these ideas into the interior
of our base and, you know,

why not have a wooden floor
in a Mars base?

This might not be a plank of wood,

this might be a thin layer of veneer
on a top of some carbon fiber boards.

And why not grow some vegetables?

These Mars bases wouldn't be able
to sustain themselves with food,

but one could grow some things
to get some crunchy lettuce now and then.

Windows, very important.

This is a Cupola, the most popular place
in the International Space Station,

designed in 1987, installed in 2010.

Took 23 years, why?

It was not because
it was technically so difficult, no.

It was mainly because from a pure
technical engineering point of view,

it's not necessary.

But from a human perspective,
it is the best place in the space station.

So, we very much took that idea
and implemented it in our Moon base,

and had skylights
bringing in natural daylight.

And take it also into the Mars base
and here in the lab space.

Why not have some natural
Mars daylight coming in?

In a way you might think,
well, this is pretty crazy.

Why would you as an architect
get involved in space,

because it's such a technical field?

Well, I am actually really convinced

that from a creative view
or a design view,

you are able to solve really hard
and really constrained problems,

and I really feel that there is a place
for design and architecture

in projects like
interplanetary habitation.

Thank you.

(Applause)