Original subtitles

How do you construct a building for humans

to live in 140 million miles away

on Mars?

Space is a really hostile environment

and humans were not made to live in space.

What happens when Seoul's city hall

is modernized with a giant wave of glass?

I didn't hear too much positive reaction,

some people say it's like a tsunami.

And how do you balance

an enormous concrete box on legs

that want to splay open under its weight?

They're very complicated to build,

it's nerve wracking.

Welcome to a world where anything is possible.

The space where innovation and creativity collide.

Part building, part transformer.

It's incredible.

Where the only limit is human imagination.

Dr. Mabry: This is mind-blowing

when you think about it.

We're talking about actually living on another planet.

Unpacking the miracles

and mysteries of construction.

This was engineering

on a scale the world had never seen.

To ask,

How Did They Build That?

NASA has its sights set on the next giant leap,

human survival on Mars.

So to prepare astronauts

for the possibility of living on The Red Planet,

they built the Mars Dune Alpha,

a 1,700-square-foot sealed habitat

where astronauts live, work,

and endure the realities of another planet

without ever leaving Earth

because getting to Mars is only the beginning.

Staying there?

That's the real test.

Space, the great unknown.

For as long as humankind has looked to the stars,

understanding its mysteries has pushed pioneers

like Copernicus and Galileo

to reshape how we see the universe.

Three. Two. One. Zero.

All engines running.

In 1969, that understanding reached

a defining moment,

as Apollo 11's lunar module makes history

with the Moon landing.

That's one small step for man,

one giant leap for mankind.

By 1976,

NASA turned its ambitions to Mars,

and the Viking 1 Orbiter sends back

the first close-up images

of The Red Planet.

Today, NASA has an even more audacious dream.

Dr. Whiting: I think it's an inevitability that humans

are going to be permanently working

and operating away from Earth,

and, really, the Moon is a stepping stone to Mars.

The question is, once you've gotten there,

how do you go about living on The Red Planet?

In 2014, NASA's CHAPEA program

begins figuring it out.

So CHAPEA stands for the Crew Health

and Performance Exploration Analog.

Dr. Mabry: An analogue mission

is a field test on Earth

that simulates the living conditions

of a real space mission to Mars.

Astronauts will get to experience

the isolation and the pressures.

This research is really important

because it's the first step in going to Mars.

So, in 2020, NASA launches a competition

to design and build the world's

first fully habitable research lab

to simulate life on Mars.

It's won by ICON,

a construction technology company from Texas.

We're the construction technology company

using robots and AI software systems

to try to, like, reimagine the way that we build.

We're sort of most known for our giant

construction-scale 3D printers.

NASA's plan is to build a structure suitable

for a year-long test mission on Earth,

based at the Johnson Space Centre in Texas.

They wanted to replicate the conditions

in living and building on Mars,

and the impacts on human health and performance

for long-duration space living.

To help design the unit,

NASA reached out to BIG,

the architects behind

the world-renowned CopenHill

waste-to-energy plant in Denmark,

and Holland's Sluishuis.

Many of us, as kids, were dreaming

about being astronauts and flying into space.

And really, as an architect,

now being able to deal with the challenges

of designing something for another human being

on another planet is perhaps the ultimate dream.

But building a habitat

where humans can live and work

140 million miles away

would mean overcoming problems

that are out of this world.

Doing this would mean coming up with a way

of transporting the construction equipment

so it has to be light enough to be carried

on the seven-month journey to the surface of Mars.

Then they'll need to devise a viable

off-planet building method that can cope

with the extreme atmospheric conditions,

including finding an entirely new material to build with

because concrete doesn't cure on The Red Planet.

Whatever they build also needs to be robust enough

to protect the crew from planetary radiation

and potential meteor strikes.

All that, and then it would need to offer

its inhabitants enough home comforts

to keep them happy and alive.

So if you think building on Earth can get tricky,

you ain't seen nothing yet.

Space is a really hostile environment

and humans were not made to live in space.

One of the biggest challenges for living on Mars

will be figuring out how to ship construction materials

and equipment up there.

I don't know the latest calculations for Mars,

but for the Moon,

it's something on the order

of between $100,000

and $200,000 per pound

to bring it to the lunar surface.

And so it's not going to be sustainable

to bring everything with us.

Back down on Earth, work gets underway

designing NASA's Mars Dune Alpha project

where scientists will live for a year.

So they didn't just want to, like, create

like an International Space Station module

and, like, live in there because they had a feeling,

that the way that we would deliver habitats

and shelter on Mars would be different.

With traditional construction methods

out of the question,

they need to think outside the box.

There's only really one logic answer.

3D printing is by far the most efficient building technology

when compared to other traditional methods.

With printing, what we can do

is we can send a robot

and have the robot build the habitat for us

before we even get there.

It's a great idea,

but now needs to be turned into a reality.

In June 2021, back on Planet Earth,

the team starts creating a structure

to simulate how we might live on Mars,

using a special device called a gantry printer.

So if you imagine two towers

and they sit on a set of rails.

And then very much like a desktop printer,

the printer goes back and forth and it prints out material,

um, and it prints out the structure layer by layer.

The material that we print with

is very much like concrete,

you want that material to remain pumpable, flowable

right up to the point when it comes out of the nozzle.

Then as soon as it comes out of the nozzle,

you want it to start curing.

Called Formcrete,

it's an ingenious evolution

of traditional concrete.

The hardening of cement relies

on a chemical reaction with water,

but it's not quick

and it's really affected by the surrounding environment.

The team here is experimenting with different mixes,

adjusting the size of aggregates,

and the different additives they put in it

to make sure it's perfect for 3D construction.

It's more predictable, more controllable,

and it's quicker.

All goes to plan printing

Mars Dune Alpha unit's walls.

But printing the roof takes a lot of thought.

We had a height limit in our printer,

and we could not print above 12 feet.

But they really needed the whole enclosure

to be 3D printed because there's not going to be

roofing crews on Mars.

If they can't do it down here on Earth,

what hope have they got of ever printing

an entire building in space?

At the Johnson Space Centre in Houston

a team of scientists, architects, and engineers

face a major challenge

with 3D-printing NASA's livable research lab,

built to inspire future habitats on Mars.

When I first saw the ambitions

for, like, the printed roof,

that was sort of like, "How the heck

are we going to pull this off?"

The whole thing has to be delivered robotically,

as close as possible to the way we would do it, on Mars.

The problem is the roof is higher

than the printer's upper limit.

We couldn't print the roof directly

on top of the walls.

You see pictures of the building.

It's basically like these arched vaults

that, um, were very unique shapes.

Um, and they actually

are different sizes and different heights.

The team, though, has a eureka moment.

We printed the arches on their sides.

We had to be able to pick that arch up, rotate it,

and then it was a very, like, careful operation

of flipping them and placing them

over the length of the building.

With the test unit close to completion,

NASA's crew prepares for their year-long simulation

of life on Mars.

The team though are already considering the problems

of trying to do this for real

on the surface of The Red Planet.

On Earth, you would use cement

but on Mars you cannot do this

because there is no pressure,

which means that the water

in the cement mixture

would evaporate instantly,

which makes this technique impossible.

Even if, like, all the other physics

would allow you to do it,

water is just, like, far too precious,

um, when you are in outer space, right?

Like, you need it for fuel,

you need it for the humans.

It wouldn't be practical

to use it as a building block, as a material.

As the team considers alternative

building materials on Mars,

inspiration comes from one of Earth's oldest cultures.

Eskimos will go somewhere

and they will build with whatever they find.

So that is what people call ISRU

or in situ resource utilization.

You'd want to go straight

from the Martian soil

to an engineered built material.

And we think that the best way to do that

is with, like, lasers, and so, melting material

and then cooling it in such a way

that creates the strength and performance properties

that you want.

Right now though, it's June 2023

and the first CHAPEA mission

begins a full year simulating living life on Mars

in the Johnson Space Centre.

Please join me

as we wish our crew well

and they enter the habitat.

Four scientists enter Mars Dune Alpha

for 378 days.

Once you step inside, it hits for you

that, "Oh, this is built for a purpose,

this is built for a mission."

This is home for a long period of time.

The first time I walked in the completed structure,

I just sat on the ground alone inside

and imagined, like,

this is the closest thing that exists

to what it might be like to live on Mars.

And I've kind of just sat in there and had a moment.

It was a really wild experience.

You do get, like, this real sense

of, like, this is a moment in time

where you are working on something

that is, uh, truly unique

and, uh, will be part of Space history.

A piece of history, which is now well

within touching distance.

We're currently around two years away

from sending the first 3D printer

to the lunar surface

that will start establishing

our capabilities for building permanent structures

for permanent, uh, inhabitation to be possible.

NASA is moving with haste

and it is really a, uh, a second, uh, space race.

As far as we've come, we sort of have an infinite sky

in front of us to continue exploring.

Seoul is a city that moves forward.

But its original city hall?

That was a different story.

Some saw it as a relic worth preserving.

Others saw an opportunity to start over.

A classic standoff between protecting the past

and building the future.

In the end, they managed to do both.

At the start of the 21st century,

the South Korean capital is reinventing itself

in steel and glass.

Buildings like Rafael Vinoly's Jongno Tower

and the high-tech Teheran Valley

all speak to the city's future-facing confidence.

Dr. Cosgrave: This isn't just about building

striking new towers,

Seoul is deliberately using architecture

and technology to reshape its identity

as a high-tech, green capital.

In other cities around the world,

it's just individual corporate skyscrapers

that are doing this, but here,

they're using this sustainable approach

across the entire civic fabric.

As part of this, in 2006,

the authorities want to replace the old city hall

with a bigger, newer, shinier one.

It's too small.

And the condition of the building was so poor.

Years of wear and tear

have taken their toll on the building,

but demolishing it is simply not an option.

The old city hall was built in 1926,

back when Korea was under Japanese rule.

And while most of the city was blitzed

during the Korean War in the 1950s,

this resilient building survived.

And as it stood as a rare,

authentic piece of this history,

it was designated as a historic property

that had to be partially preserved.

So it's decided that rather

than start from scratch,

the new city hall somehow needs

to incorporate the old one.

And that makes it a lot more complicated.

In February 2008,

after two years of deliberations,

respected local architect Kerl Yoo

is selected for the job.

He arrives with big plans.

I like openness and transparency

and bright light

and big space.

That's what I like.

Kerl Yoo's extraordinary vision

is for a wave-like wall of glass

that will loom over the old city hall.

To achieve it will take multiple engineering miracles.

Not least, making sure the old building

doesn't fall down during its massive reimagining.

The offices themselves

will be nothing out of the ordinary,

but Yoo's love of bright light spaces

will start to show

as they're encased in a vast glass atrium

that will resemble a giant wave.

Then, they'll need to figure out

how to float bubble-like public spaces,

called blobs, within the wave,

designed to glow from the inside

before somehow supporting

the world's biggest living-wall

and creating a huge curved glass curtain

that reflects the heat of the summer

but insulates against the cold of winter.

It's a very bold vision,

even by Seoul's very bold standards.

In fact, perhaps it's all a little too bold.

I didn't hear too much positive reaction.

Some people say it's like a tsunami.

I like that.

Spring, 2008.

Work begins,

and already there's a problem.

It turns out the columns and beams

that hold the old city hall up

are fine doing the job they're currently doing.

But the construction will put them

at serious risk of collapse.

In Seoul, South Korea,

the team building the new city hall

has a big job on its hands.

Before any real work can start,

the old town hall needs some serious intervention

to stop it from falling down.

Dr. Cosgrave: This wasn't enough on its own, though.

They also had to create a forest of piles

going down nearly 90 feet

under the old building to support it.

In total, 137 piles are installed

before the team can turn its attention

to the huge new build,

which will not only go up 175 feet.

It will also go down.

Normally, you'd start by excavating

the five-storey basement.

But that will cause a lot of disturbance

which won't be great for the old town hall.

So they opt for top-down construction.

Dr. Kwami: What that means, that you start

by building floor minus one first.

Then you create minus two underneath and so on.

It's complex, but the real advantage here

is that you create less disturbance

to the ground and the surrounding buildings,

namely the delicate old city hall.

It also means they can construct the levels

of the new city hall above ground

at the same time.

It's all pretty straight forward work

till they get to the three separate public spaces

called blobs.

Achieving Yoo's vision of each

being a huge floating bubble

is something of a challenge.

For inspiration,

they look 5,700 miles away,

to the English countryside.

The Eden Project is home

to the world's biggest indoor rainforest,

made possible by the extraordinary domes.

It's covered in this amazing plastic

called ETFE,

ethylene tetrafluoroethylene,

which is incredibly light and very tough.

But here's the clever bit.

You can fill it with air and then it becomes

an incredible transparent insulator.

We could make any form and size.

It has flexibility.

Unable to support itself,

the ETFE will be wrapped

around a giant, twisting steel skeleton.

Their challenge is to bring

all these custom-made steel

and ETFE pieces together,

mid-air, and hope they actually fit.

The high-wire engineering pays off.

Every single custom component slots into place

on the first try.

By August 2012,

Yoo's floating blobs are officially complete.

Now to cover the facade of the building

in the 13-storey glass wave

that overlooks the public square,

and the team have slightly different reasons

for loving it.

I want to make the building very connected

with the plaza.

Yoo's glass wall

will eventually lean out over the plaza,

but that means it naturally wants

to fall over.

So until it's finished,

the whole thing will be supported

on a network of safety cables.

Finally, the frame reaches the roof

where it's anchored into the main building.

Now locked into place, the temporary cables

can be removed.

Next, 7,000 special glass panels

arrive from the United States

ready to be fitted into the frame.

The glazing costs millions of dollars.

And weighing roughly 300 pounds each,

it's a puzzle of different shapes and sizes.

And fitting 7,000 of them to a building

of this size and this shape is going to push the team

to its limit.

In Seoul, South Korea,

the team modernizing the old city hall

as a giant glass wave faces a huge challenge.

Fitting the 13-storey structure with 7,000

specially-made glass panels, some over 13 feet in length

and all of different shapes and sizes.

Not only must they all be fitted in precisely

the right order and position,

but the trickiest bit

will be installing almost 1,600 of them

to the underside of the giant wave itself.

At the time, glazing something

of that size and that shape had never been done before.

Because they were using flat panels

on a curved surface, every joint was different.

Amazingly, within 10 months,

the huge wave is all but complete,

and the glass itself does much, much more

than just look good.

Dr. Cosgrave: Here, the glass has been coated

in microscopic layers of silver

and has argon gas between each of the panes.

Now, what that means in practice is that

it allows the light in but blocks the heat

from the UV and infrared light in the summer

and insulates the building in the winter.

Although thoroughly modern,

the building also takes inspiration

from centuries of Korean architecture,

like its large overhanging eaves.

The finishing touch

is a record-breaking

16,000 square foot green wall

along the entire length

of the internal offices.

On August 31st, 2012,

construction is complete

and soon after in October,

a grand opening ceremony takes place...

...welcoming this spectacular

glass tsunami to the heart of the city.

When you come there first,

you look up.

Most people do that.

I like that.

The old building is now home

to the city library and connects seamlessly

to the new city hall via a glass walkway.

There, a stunning seven-storey vertical garden

allows the city to take a cooling break

surrounded by nature.

This is something so different.

They play with light and with movement,

with the green and with the balloon.

It's great.

Behind the green wall

are the government offices,

while the balloon-like blobs

contain a cafe and a concert hall.

It's a triumphant end to a long

and controversial journey.

Most of the time

when people see something new,

they reject it.

It's human nature.

Negative or positive,

showing interest is better

than no interest.

Dallas had a vision, to create a modern home

for Asian art in the heart of the city.

But there was a problem.

The architects wanted the museum to float,

barely touching the ground,

which meant that building it

out of 8,000 tons of concrete

was what you and I would call a terrible idea.

Or what architects call a fun challenge.

From the Guggenheim in Bilbao,

to the Twist in Norway,

and LA's Getty Centre, some of the world's

most exciting architecture

is born of families

gifting their extensive art collections

to the public.

At the turn of the 21st century,

Texas has its own family of charitable art lovers,

pioneering real estate magnates, the Crows.

Trammell and Margaret Crow

were longtime residents of Dallas

and international leaders in business,

and they loved Asian art.

They accumulated an incredible collection.

By 1998,

the Crows decide to donate nearly 600

of their best pieces to the city

and build a museum to house it in.

The Crows passed away

about 15 years later.

The family looked at of what could happen

if the collection was given away.

In 2019,

the family gifts the rest of the collection

to the University of Texas at Dallas,

along with $23 million for a museum.

This will be the first stage of an ambitious

arts and design complex.

Their hope was for a gathering place

for the students,

a commonsthat would bring together

culture and history

in unprecedented ways on this campus.

And we wanted, um, innovation.

California based architects

Morphosis, led by Arne Emerson,

takes on the challenge of leading the project.

Bringing together music, art, knowledge,

student daily life was really important

and that was the genesis of the idea

that drove all the decisions from the beginning.

The first building to be constructed

and that will set the tone

for this bold transformation of the campus

will be the 68,000 square foot

Crow Museum of Asian Art.

To create space for students to mingle in the shade,

they will need to find a way of balancing

the two gallery spaces made of concrete and steel

more than 20 feet above the ground

on a series of V-shaped columns.

Next, the team must join both galleries

through a complex curved atrium,

overcoming a geometrical puzzle

of winding glass that joins with curved steel

and concrete to form the main lobby entrance.

Finally, they'll have to clad the whole building

in a series of bespoke pre-cast panels,

each of which is individually designed

and hung vertically from just two points.

It may look like a thoroughly modern piece of architecture,

but some of it was inspired by medieval Italy.

I had been travelling back and forth to Bologna,

and the idea of colonnades

are incredibly important there.

You have these covered exterior walkways

that shields you from the elements,

for people to really hang out all year round.

To recreate these covered spaces here,

all they need is figure out

how to keep an entire art museum

20 feet off the ground.

Building a volume that looks like it floats in space

is incredibly complicated.

The sheer forces that you have to fight are unbelievable.

In May 2022,

the team breaks ground on the 12-acre site.

Their first challenge, creating foundations

that will hold up the huge gallery spaces

which measure some 68,000 square feet,

but will only be supported at nine points

where the columns meet the ground.

The entire idea of a foundation

is to transfer forces created by the building

down to the ground in a more distributed manner.

The problem here is that these forces

were being concentrated

where these columns meet the ground.

We call it point loading and it requires

a special sort of foundation.

The foundations for the column

consist of five 48-inch piers.

And those piers go

all the way down to bedrock.

And that gives it the support.

With the foundations dug,

the team turns its attention

to the nine pairs of sloping concrete columns.

These have to hold the building,

so they need to be pretty special.

The V columns, they're not just going up,

they're actually curving.

They're very complicated to build

because of the complex geometry of them.

To ensure they're strong enough

to hold the enormous weight

of the building on top,

they need a special concrete mix

which is double the normal strength.

The concrete that was poured

was very specific for these columns.

Eight thousand PSI, which is a very hot,

very strong concrete.

We also had to take into consideration

the temperatures.

So once you pour concrete,

the concrete will spike in temperature.

But we could not allow the temperature

to spike over 160 degrees.

And that can cause micro-cracking

deep within the concrete.

In Dallas, Texas,

the team building a huge concrete box gallery

that floats on a handful of V-shaped legs

must find a way to stop the super strength concrete

from getting too hot.

The problem with high-strength concrete

is that it has a much higher cement content,

and that creates a lot more thermal energy as it cures.

Now, if those temperatures go above 160 degrees,

you get internal expansion

and micro-cracking deep within the concrete.

Kristin and the team

monitor every load.

The temperature of the concrete

when it showed up to site was critical.

If concrete showed up above 70 degrees,

we had to turn it away.

But ultimately, we coordinated and got everything correctly.

With the columns cast

the team's next problem

is how to stop them splitting apart.

With a V-shaped structure, weight on top

makes the columns want to splay outwards.

The solution is a tie beam, which, as the name suggests,

ties the two columns together to stop them splaying.

With the foundations

and columns set,

the team starts on the concrete floor plates

for both galleries,

while the massive steel framework skeletons

that will contain them are fabricated off site

at a specialist steel manufacturer.

Dr. Cosgrave: The gallery frames

have to be incredibly strong.

They will support over 640,000 pounds

of concrete panelling on the outside,

plus they have to be safe enough

to house priceless exhibits,

some of which weigh 30,000 pounds.

The steel frame consists of approximately 500 tons

of structural steel,

including multiple steel trusses,

a couple of them over 200 feet in length.

Once completed, the component parts

are brought to site

where they need to be attached precisely

to the base plates, and welded.

We had to make sure

everything lined up and that the concrete

and the embeds in the concrete were placed correctly

so that then you could tie the steel into that.

And if anything was off, it wouldn't work.

When you have a structure that's complex

as this one, it's very easy

for it to get overwhelming very quick.

Slowly but surely,

the huge steel exoskeletons come together.

Finally, they're complete.

It was a proud moment,

very much felt like, um, a sense of accomplishment.

Work can now begin on the 167 panels

that will make up the museum's facade.

The Museum is clad

in precast concrete panels.

Precast meaning they were poured off site

and then brought to site.

These precast panels are very unique.

Some are curving in two directions,

and that's where the challenge came in.

To speed up the production process,

Emerson designs an ingenious mould

that allows the elements to be reconfigured

and aligned into any shape.

Each one of these panels

are comprised of white concrete

and has these pieces that are pushed in

and pieces that pulled out.

And what that starts to create is this really kind of textile,

three-dimensional textured pattern

that starts react to the overall Texas sun.

With all 167 made,

640,000 pounds of panelling is brought to site.

These panels are hung vertically

and they're attached to all the structural steel back behind.

Which is a lot easier said than done.

They're installed slanted

so gravity and the weight of those panels

are going to cause them to kind of pull,

so extra engineering has to be done

to ensure that those are correct.

Each panel is loaded by two points.

If you tried to load them from the bottom,

they would want to buckle.

If you can imagine a piece of paper,

you can hang a piece a paper,

you can't load a piece of paper from the bottom,

it wants to buckle.

So when we're hanging panels from the top,

we do fasten them with anchors at the bottom

to kind of prevent that.

As the panels are fitted,

they turn to the final

and most challenging job,

uniting the two galleries

via a vast curving central lobby.

We identified the atrium as one area

of this building that is the most complex.

One challenge for engineers

is dealing with places

where several materials come together.

This is because they all behave differently.

Above the atrium, we have steel,

glass, and concrete

all coming together at different angles

in a small, condensed area.

So the steel frame, which is holding

all of this together,

suddenly becomes impossibly complex

as it tries to deal

with all of these merging materials.

The curvature adds a complexity

because you had to do three different major components

of the building coming together in one spot

with a very complex geometry.

To overcome the problem,

the team designs a spine built of 17

individually shaped steel pipes.

Our detailers actually dubbed them

as the steel noodles.

Ultimately, what they're doing

is they're creating the backbone

that everything else then builds off of.

The next challenge

will be getting them all to fit.

The steel noodles comprised of 17 individual

uniquely rolled steel pipes.

The complexity of these was unique

because you'd picture a regular rolled material

as kind of straight going in one direction curving.

These were constantly going in and out,

up and down, and almost eclipsing on itself.

So the team won't know

if they've been designed correctly

until they're all in place,

ready to be connected.

It was so complex because each individual piece

is unique in its radius or curve.

Getting that set exactly in the right spot

from a three-dimensional standpoint

proved to be very, very challenging.

Slowly but surely,

the noodles are fitted into place,

connecting the central curving atrium

to both wings of the gallery.

It's exciting, but it was also nerve-wracking.

The structural steel fabricator did a great job.

In September 2024,

just two years after work began,

the museum opens its doors for the first time.

The end result is really something

that's quite beautiful,

that glimmers in the Texas sun.

And when you get up close to it,

you can really start to see how the sun

and the light and the textures start to animate throughout.

I feel like we got the museum

that we wished for and dreamed for.

The gallery buildings

rest on impossibly small footprints,

creating 11,000 square feet

of covered colonnades

where the university students

can gather, whatever the weather.

It's special.

Once you stand next to it and understand,

wow, these columns are holding up

this entire building.

It's kind of surreal.

It's a very challenging project,

but also very rewarding.

It just is a beautiful building,

and I'm happy to say I was a part of it.

Inside, an extensive

and rotating selection of historic

and contemporary Asian art

is on display for all to enjoy.

The Crow Museum is one of the most

complete projects I've ever worked on.

It's about wonder and community

coming together into one building.

In a world where imagination,

innovation, and creativity

define the spaces that surround us,

How Did They Build That shows again and again

that humankind will overcome the seemingly impossible.