♪ ♪ NARRATOR: We live in a built world.

Engineering and technology, built upon innovations and inventions, stretching back thousands of years.

Some of our creations, like machines, boost our bodies' abilities.

Others help us reach outside our comfort zones.

We have left an indelible mark on the planet, and now the time has come to use our skills to make a better world.

Building taller buildings... ...that stay steady in the wind.

DAVID FIELDS: As extreme as this feels, this is nothing compared to what the building's designed for.

NARRATOR: Or submarines that dive deep... PATRICK LAHEY: Imagine a craft that allows you to explore a part of our world that you simply couldn't see any other way.

NARRATOR: ...to give an unprecedented underwater view.

EDIE WIDDER: It's like being in a goldfish bowl, only the fish are on the outside and the people are on the inside.

NARRATOR: Clothes that let us go farther to places we never could before.

Or even a new structure to replace the International Space Station.

SHAWN BUCKLEY: We could put three floors inside this, have up to six people live for months on months.

NARRATOR: "Building Stuff: Reach It!," right now, on "NOVA".

♪ ♪ ANNOUNCER: Major funding for "NOVA" is provided by the following: NARRATOR: Humans.

Unlike a lot of other animals, we're not exactly fit to thrive in the wild.

We lack fur to protect us from cold.

And speed to outrun predators.

(big cat snarling) Exposed to the elements, many of us would struggle to survive.

But luckily, we have other strengths.

ANDREA ARMANI: Engineering is all around us and we often don't recognize it.

One of the things that engineering lets us do is to do things that we can't do with our bodies.

NARRATOR: Ever since our ancestors first evolved, humankind has refused to stay put.

MARIA YANG: Humans are infinitely adaptable.

We live all around the world in different climates and conditions.

Engineering has made that possible.

ALI HAJIMIRI: I think it's in human nature to solve problems.

And solving problems is the basis for engineering.

MAN: Venting tanks.

NARRATOR: We've learned how to compensate for our vulnerabilities.

By building stuff... (explosion) ...and reaching to every imaginable place.

♪ ♪ We've been building skyward for thousands of years.

From raising huge stone monuments, to building massive pyramids, to framing today's mega-tall skyscrapers.

DAVID FIELDS: Million dollar view.

NARRATOR: Each step higher presents new engineering challenges.

Chicago's storied Michigan Avenue, towering over 800 feet, is 1000M-- a 73-story skyscraper under construction along the city's lakefront-- where it will be fully exposed to the city's notorious winds.

LYNDA DOSSEY: You can see some pretty decent wind loads.

So we have some unique conditions here.

♪ ♪ DAVID STEFFENHAGEN: Each building is unique and it's kind of its own recipe that gets put together.

NARRATOR: Chicago is often considered the birthplace of the skyscraper.

The Home Insurance Building, constructed in 1885, is widely considered to be the first skyscraper, though only ten stories tall.

Over the decades, engineers have relied on a blend of art and science to cope with wind.

NEHEMIAH MABRY: Not only are you considering the wind as it is naturally occurring in that space, but you take a city like Chicago in which there are several other tall buildings, you have to design not just for how the wind would naturally occur, but for how the wind would also be altered by the tall buildings around it.

NARRATOR: David Fields is the chief structural engineer at 1000M.

In our modern era, we're seeing buildings get taller and taller and more and more slender.

This is pushing the ragged edge of structural engineering and what can be built and what can be cost effective.

NARRATOR: David is responsible for ensuring the structure's strength and integrity.

And of all the forces that can damage a skyscraper, wind is one of the biggest threats, not only to the structural integrity of a building, but to its very livability as well.

It can make people physically ill with a kind of high-rise sea sickness.

It's a problem that only became apparent as tall buildings evolved from heavy structures like the Empire State Building to today's lighter, steel-framed buildings; like 1000M.

Originally designed by the late architect Helmut Jahn, now overseen by architect Lynda Dossey.

DOSSEY: Architecture is a balance between beauty and function.

We are hired to solve a problem and solve it beautifully.

The ultimate goal is to deliver a feasible, functional building.

Looking at our structural plan... FIELDS (voiceover): I think of structural engineering as designing the bones within a body.

We think about where to put a core, where to put bracing, and that happens very, very early.

And it shapes, fundamentally, almost everything within the building.

DOSSEY: I think you gave us an extra few feet.

(voiceover): Structural engineers and architectural engineers, in some ways, they're cut from the same cloth.

We do push on them a lot to try and achieve our aesthetic goals, but at the same time, we have a responsibility to safety and comfort.

NARRATOR: So why is wind such a problem?

FIELDS: As wind blows on a building at low speeds, it tends to approach a building and wrap around it smoothly.

As the wind blows faster and faster, it starts to eddy on the backside.

As wind blows even faster, those eddies-- we call them vortices-- they peel off.

They peel off the building rhythmically and kind of side to side.

This gets a building rocking and swaying at high wind speeds.

DOSSEY: If you're building a rental building or if you're building a condo building, these are people's homes.

They live in them and you want them to feel as comfortable there as they would anywhere else.

All right, well, here we are.

Top of the building.

NARRATOR: Luckily, there is an ingenious engineering solution under construction here on the top floor.

Two large concrete boxes, called mass dampers.

Both will be filled with water to suppress building sway.

As wind pushes the building in one direction, the water with all its weight sloshes in the opposite direction.

This counterbalancing motion "dampens," or offsets, the sway of the building.

Here we have a demonstration of tuned sloshing dampers.

We have two frames that have effectively the same natural frequency.

Now on top of these, we'll put two identical damper boxes.

We'll fill one with just the right amount of water.

And we'll see both how much less it sways and how much quicker the swaying stops.

NARRATOR: The box with water settles faster than the box without water.

What works here is exactly the same that works here on a much larger scale.

NARRATOR: The two large damper tanks are located north and south of the building's concrete core, to help combat frequent intense winds at high altitude.

The tanks are 40 feet long, ten feet wide, and 15 feet tall and will hold up to 11 feet of water, about 33,000 gallons each.

which is only about 0.2% of the mass of the building itself.

♪ ♪ FIELDS: So this big box, it's basically a swimming pool.

The water pressure will try to push it outward.

That's why we have rebar very densely all throughout these walls.

NARRATOR: Next comes the outer formwork.

When complete, the construction workers will pour concrete between the forms to make the walls.

FIELDS: It's like the guys are working with more urgency now that the forms are going up.

Everybody knows they got to get their part done.

NARRATOR: And although the construction team is very experienced, people can still make mistakes.

FIELDS: Fortunately, we caught an issue just before the form work went up-- at the bottom of the tank, where the water pressure is greatest, we have major piping coming through the wall.

NARRATOR: The builders failed to install critical rebar at the weak point in the tank wall created by the piping.

FIELDS: The guys are solving the issue.

This is happening about five minutes before the formwork closes things up.

This never would have been seen if we weren't here.

NARRATOR: Embedding steel bars reinforces the concrete.

Concrete is very strong in compression, but it's brittle.

Steel is flexible-- so combining the materials creates a structure both strong and resistant to failure.

It's going to have 24 inches of un-reinforced concrete, so we can kind of trim it out.

SEAN TATUM: Having the engineers on site it's critical because they have very in-depth knowledge, obviously, of the structural design.

This way, if there are any issues that arise, those get to be mitigated up front very quickly.

Uh, and it makes everyone's job that much easier.

NARRATOR: With the damper tank mold now fully constructed, it's time to pour the walls.

♪ ♪ (concrete pouring) Then, just as the pour is ending, a storm rolls into Chicago.

(lightning strikes) It's the perfect opportunity to get a benchmark reading of how much the building sways before the dampers are filled with water.

David holds a monitor connected to an electronic motion sensor called an accelerometer.

It's attached to the building, and reports sway measured in fractions of G-- Earth's gravity force.

FIELDS: So we're taking our first frequency measurements of the building; as extreme as this feels, the wind, the rain, the thunder and lightning we're seeing and hearing, this is nothing compared to what the building is designed for.

The building's moving.

We're reading four milli-g right now.

These are our first dynamic measurements.

We'll take these back to the office, decide how much water to put in the tank, and then we're tuned.

NARRATOR: Using water to stabilize sway has roots in the 1800s, when it was discovered that ships can achieve greater stability by pumping water ballast into the hull.

The amount of water can be easily adjusted as it's readily available at sea.

It's very much to an engineers' advantage to think back on how other solutions and other accomplishments and achievements in the past can perhaps serve as starting points, or even informers for what we are trying to do today.

All design is redesign.

So if you think about it, you're taking things that have existed in the past, but you're making them incrementally better.

You've thought about it in a new way, or you're bringing in a new technology that didn't exist before.

NARRATOR: When 1000M is nearly finished, David returns to tune the damper, making a final decision about exactly how much water to put in the tanks.

So today is the culmination of six years of planning and coordination and engineering.

And we'll finally see exactly how much water to tune it and damp it, so it's comfortable for everyone who will live here.

Here we go.

FIELDS: I'll go check the inflow.

The water's flowing in.

DOSSEY: It's very exciting.

It means we're getting close to the end.

It's just a milestone moment.

FIELDS: We're turning on our application.

Right now, we have an accelerometer.

This is very sensitive.

So even on a modestly windy day like today, we know exactly the motions we're getting to micro-g's; these are tiny percentages of the acceleration of gravity.

Last time we took readings, we were seeing roughly four milli-g's.

Today, we're down closer to one half of a milli-G. Part of that's a function of the tanks being filled, part of that's a function of it's a less windy day to begin with.

By tomorrow morning when the tanks are full, we should see the building sway being about half of what it would otherwise be.

DOSSEY: That's one hell of a view.

It is incredible.

♪ ♪ NARRATOR: It's views like this that reveal just how extensively humanity has developed the land, Yet over 80% of the oceans remain unexplored and untouched.

There's a reason for that.

Of all the environments that support life on our planet, the most forbidding and remote are the deep oceans, where the furthest reaches lie more than six miles below the waves.

WIDDER: Our ocean is the basis for life on this rock, and we are impacting it in ways we don't even begin to understand.

And the first step is always exploration.

CAMERON: The more you understand the ocean, the more you love the ocean, the more you're fascinated by it, the more you'll fight to protect it.

NARRATOR: Urgency to combat climate change...

Here we go.

NARRATOR: ...has spurred new efforts to explore ocean depths... TRITON TEAM PILOT: The sub is extremely maneuverable.

LAHEY: Imagine a craft that allows you to explore a part of our world that you simply couldn't see any other way.

NARRATOR: Engineering a safe submarine is extremely challenging, and mistakes can be fatal.

NEWS ANCHOR: Catastrophic implosion.

The unthinkable became all too real... NARRATOR: In 2023, the world was horrified by the implosion of the OceanGate Titan submersible that was on an expedition to explore the Titanic.

The disaster killed five people, including OceanGate's co-founder, Stockton Rush.

I've been safely down to the Titanic wreck site 33 times.

And to me, the idea that, that lives could be claimed by an implosion in this day and age is almost unfathomable.

It was a bad idea.

And they were warned.

NARRATOR: The carbon fiber used in the hull may have been a critical fail point.

The material is prone to buckling under pressure, especially when combined with the elongated pill shape.

But that was the Titan, not to be confused with the Triton submersible, being manufactured in Sebastian, Florida.

Triton's design approach is rigorous.

Here engineers are building subs designed to take non-specialists hundreds and even thousands of feet below the surface, safely.

Patrick Lahey is the co-founder of Triton Submarines.

LAHEY: Safety begins with design.

It carries all the way through to the selection of materials, the formation of those materials into parts, those parts made up into assemblies.

Those assemblies then tested and validated on their own, then incorporated into the complete vehicle, which is then tested again.

ARMANI: If you're an engineer, it is your responsibility to do things in a manner such that the end product is safe.

Because at the end of the day, people are relying on you to make a safe product.

NARRATOR: Altogether, their subs have logged tens of thousands of hours underwater without any incident.

Increasingly, the vehicles are being used for scientific research, filmmaking, and underwater exploration.

LAHEY: So this is our most compact three-person sub.

The pilot sits in the back, two passengers in the front.

They have this incredible, completely unobstructed view from this acrylic pressure boundary.

NARRATOR: The pressure boundary is a perfectly round plastic orb that is transparent.

It's like being in a goldfish bowl, only the fish are on the outside, and the people are on the inside.

And it's invisible.

You really feel like you're a part of the ocean.

NARRATOR: The boundary's main job is to keep occupants safe from the crushing water pressure pushing in from all sides.

A sphere is one of the strongest shapes in nature.

A spherical hull experiences the same amount of pressure at every point on its surface, minimizing the chances of structural failure.

So far, the only subs that have made it to the bottom of the Mariana Trench-- more than six miles below the surface-- carried their passengers in spherical enclosures.

And all were made of metal, like steel or titanium.

Test, test.

We good on audio?

NARRATOR: Film director and ocean explorer James Cameron, who is an investor in Triton, wants more people to experience the deep the way he has.

CAMERON: The goal of Triton Subs is to make the best commercial-- which also means scientific-- subs in the world, and to make them widely available.

NARRATOR: In 2019, a Triton titanium spherical enclosure sub completed one of the most ambitious global expeditions in modern history, taking people-- numerous times-- to the deepest spot in each of Earth's five oceans.

Including the Challenger Deep, in Mariana Trench.

(cheers and applause) The geometry of a sphere limits its usable space.

The designers wanted to increase the number of passengers beyond what a sphere could reasonably hold, so they settled on an elongated shape made from a common, yet deceptively strong material: acrylic.

JOHN RAMSAY: Acrylic is an incredible material.

It's completely transparent.

Unlike glass, where even after six inches, you're starting to see quite significant discoloration.

NARRATOR: Increasing the thickness of the acrylic increases its strength and ability to resist the pressure of the water, while retaining visibility.

It's completely different from anything that's preceded it.

We wanted to be able to put the most people into the smallest volume possible.

NARRATOR: When it's complete, this sub will hold up to nine people, including a pilot.

they call it AVA.

It's designed to safely dive depths of up to 600 feet.

The unusual shape is the work of engineering firm Dark Ocean, and their principal designer, John Ramsay.

RAMSAY: To accommodate nine passengers, it's incredibly difficult to do that in a, in a traditional sphere.

The way the 660/9 AVA works is it just takes that sphere and it optimizes it for the passengers inside by stretching it out and allowing everyone to sit side by side.

NARRATOR (archival): Down into worlds never before seen... NARRATOR: This design draws from decades of research on acrylics.

RAMSAY: There's an 800-page kind of bible of submersible acrylics and you can go through and see every bit of testing that was done.

The material that makes this possible is acrylic plastic.

(knocking) CAMERON: Everything you do in engineering is based on what other engineers before you have done.

If somebody's got a great, elegant solution, why reinvent the wheel?

NARRATOR: At the factory, the team is attempting to attach AVA's pressure hull to its steel chassis.

They've never had to maneuver a shape like this.

Okay, uh, Chris bring yours up a little bit.

(cranking) NARRATOR: One slip, and the acrylic could be damaged or scratched.

One, two, three... Just the corner.

NARRATOR: The team positions the metal chassis beneath the elliptical hull.

It needs to go towards you a little bit, Monroe.

(indistinct chatter) Ready?

(straining) That doesn't look bad.

Let's just keep a little bit of tension on it.

MAN: Yep, it has tension still.

NARRATOR: Despite the best efforts of the engineers...

There we go.

NARRATOR: ...there are still small adjustments to be made.

ARTHUR MUTTOCK: So we are trying to thread in this big pin now.

Some of the bits of machine to within a tenth of a millimeter or less to, to get that nice fit.

STOTT: Come back, Monroe, a little bit.

Whoa, whoa, whoa.

Go...

Hold tension, it's slipping.

Give me a freaking heart attack.

STOTT: I mean it is so freaking close.

It's not going to go anywhere right now.

So just come down on your forks, Monroe.

Okay.

Tilt forward.

Okay.

Backup.

NARRATOR: The acrylic hull is secure for the moment.

But they'll have to stop for the day to tweak the size of the screws.

Does it always go according to plan?

No.

Am I really pleased with how far we've got today?

Oh, yes.

MABRY: When we're solving problems, when we're building things, we're engaged in this process of getting our hands dirty and actually doing some trial and error testing to see if what we've, we've built was effective, if it worked.

NARRATOR: Testing needs to be particularly rigorous when lives are at stake.

HAJIMIRI: You are implicitly relying on the people who designed it and built it to make sure that they've thought about how it can fail, and if they've come up with ways to get around that.

NARRATOR: Today, every new vehicle, be it a car, airplane or submarine, is subjected to thorough testing and review throughout the engineering process.

(crash) The true testament to its reliability ultimately hinges on obtaining certification from an independent third party.

LAHEY: They make sure that your assumptions are not flawed, that you're not doing something that could be dangerous, that it complies with an internationally recognized set of rules.

NARRATOR: The failed Titan submersible was never officially certified.

CAMERON: If you're putting passengers on a sub, you need it to be qualified by some independent body, whose job it is to make sure that that vehicle is safe.

♪ ♪ (indistinct chatter) We are going to try to launch just before noon.

NARRATOR: The AVA sub is now ready for its first dive.

Senior approval engineer Ionel Darie is on-site today for final checks of all the sub's vital systems, making sure the submersible is safe for passenger dives down to 600 feet.

DARIE: Everything went great, we can issue the final certificate for this submersible.

NARRATOR: After getting the green light, The sub is ready to make a shallow dive.

(hydraulics hissing) MAN: Top sides, top sides.

Hatch is closed, life support is on and good.

MAN (on radio): Roger, you have permission to dive.

(splashing) And we're on our way.

♪ ♪ MUTTOCK: Amazing.

I mean, this is the first time I've been down, and it's been two and a half years of work.

This is the result, and it's a magnificent one.

Really loving this.

NARRATOR: If Triton is able to fulfill its mission of building more submersibles, many others will soon be able to have their first ride into the deep ocean.

WIDDER: This is this other universe that is most of our planet, and it's such a magical place.

And to be able to now explore it in comfort is a phenomenal ability that is open to more and more people.

(indistinct radio communication) ♪ ♪ NARRATOR: Our inventions can act as force fields between our bodies and the environment, protecting us from extremes.

You can see them all around us: what we live in, what we move in, and even what we wear.

At a textile research laboratory in North Carolina... ♪ ♪ ...engineers are preparing to set a mannequin on fire.

(igniting) (flames roaring) Their goal: collect data that will help make safer fire-fighting suits.

And researchers are also focused on finding solutions for women firefighters who often struggle to work in suits typically designed for men.

(flames crackling) ROGER BARKER: What we do can be life-saving.

So there are no higher stakes than that.

Textiles are the unsung heroes of the world, period.

(sirens wailing) NARRATOR: As firefighters battle flames and smoke, their clothing and gear is the first line of defense.

But their suits can also contribute to a hidden danger: heat stress, when the body's core temperature and heart rate rise to unsafe levels.

About 40% of work-related firefighter deaths are the result of cardiac incidents due to heat stress.

The big question: how can we keep firefighters safe from flames and keep their body temperatures within the suit from rising to heat stress levels?

For decades, Roger Barker and his team have been building new instruments and test methods to measure both thermal protection and comfort.

An earlier iteration of their mannequin couldn't move.

In a real-life situation, a firefighter would almost never be stationary.

After three years of development, researchers are ready to light up their moving mannequin.

Fire it up, John.

(beep) (flames roaring) NARRATOR: Thermal sensors throughout its body allow them to study how heat is transferred or blocked by the clothing-- and if this motion creates new avenues for hot air to enter and move inside the suit.

BARKER: So now we're seeing the combined effects of the flame and the stresses that are being generated as the dynamic pyroman moves their arms and their legs.

(flames roaring) NARRATOR: With mannequin simulations, they can predict how long it will take for a firefighter to sustain burns.

They also test for seams breaking open, fabric ruptures, and the effects of garment fit and design.

The tough outer shell protects against flame and abrasions.

The middle layer is a moisture barrier that keeps liquids from penetrating the suit.

The innermost layer resists any remaining heat that gets through the first two layers.

This system offers high protection-- up to a point.

(light clicks off) A proper fit and design also play a protective role.

MCQUERRY: Trying to create that optimum balance between protection and comfort for all firefighters is so important.

NARRATOR: And for women in the field in particular, an ill-fitting suit designed for a man can put them at higher risk of injury while on the job.

HILARY DAVIDSON: The fabric on its own isn't going to save you.

It can be the most engineered, up-to-date, advanced composite fabric, but how it's put together, how it's worked around the body, the fit, every kind of material aspect of how that fabric is used that is going to really make it an effective technology.

NARRATOR: Today, there are about 90,000 women in the fire service in the United States.

80% report that their gear does not fit properly.

CASSANDRA KWON: They are doing the exact same actions, the same motions, as their male counterparts.

So, you know, they should have something that actually works for them.

NARRATOR: The goal for this research team is to develop and design a prototype suit made specifically for female firefighters.

MCQUERRY: A large majority of firefighting PPE on the market today is made with a male body in mind, and it's patterned in that way.

There is sizing for women, but that sizing is not always achieved by initially starting from a female pattern.

NARRATOR: Women also vary more in shape than men do.

Males are a little bit more up and down, while females have curves because of the hips and the bust areas.

I've always had an issue with the fit of my jacket needing more space up in the chest area.

NARRATOR: In order to accommodate, women will often be given larger jackets.

DONAHUE: Whenever you go up in sizing for jacket, it makes down here larger as well.

So, you know, you've got the good mobility and fit up here, but then sometimes down here, you're going to have some extra fabric.

MCQUERRY: So a really tailored fit is important.

It's critical for their mobility, for their vision.

It's also critical in terms of heat stress.

NARRATOR: An oversized garment creates thicker air gaps, increasing insulation and potential protection from outside heat, but larger air gaps also restrict the firefighter's ability to lose body heat to the outside environment, trapping heat inside the suit.

KWON: We've had female firefighters say that the collars on their jacket are really tall.

The length of it rising up from the collar bone and how much it takes up your neck.

KWON: If you're a smaller stature female firefighter, that can be problematic, because when you're wearing your SCBA mask, your helmet, you really start limiting mobility.

And if even... (helmet knocking) ...the air pack itself, my helmet really hits it.

So it's hard to look up, so you can see what's going on above you.

Imagine you're in a fire, you have everything sort of caught here at your neck.

You're putting yourself at higher risk for injury because of your minimized range of motion.

NARRATOR: Protecting the body from the elements is a pursuit as old as we are.

♪ ♪ (sewing machine whirring) DAVIDSON: The history of clothing is also a history of the relationship between people and their environments.

Although humans started off taking the skins of other animals and putting them on their skin, once they discovered how you can use plant fibers to make, first of all, string and thread, and then weave that together and make fabric.

Fabrics have always kind of started and then inspired new types of innovations and technologies.

NARRATOR: Like the invention of the eyed needle.

The first ones were made of bone.

And once you have this concept of bringing two things together, a whole lot of engineering possibilities open up to you.

♪ ♪ It gives us seams.

It gives us tight seams, which means you can start to think about having things waterproof or windproof.

NARRATOR: Or even fire-resistant.

Earlier firefighter suits were made of wool, chosen for its natural flame resistance.

Today's suit offers much better protection from fire, but it's not as breathable, meaning body heat can get trapped more easily than it did with wool.

Firefighting is physically demanding work.

KWON: You're working hard, you're entering a hot environment.

You know, you create all these microclimates inside your suit.

BARKER: Working at high levels of exertion, if their body traps too much heat, they may be subject to heat stroke or even worse, cardiac events.

NARRATOR: One of the ways our bodies try to cool down is by sweating.

But that only works if the sweat can evaporate.

A suit's ability to release heat is measured with this female mannequin named Liz.

♪ ♪ She sweats through nearly 100 pores designed to mimic human perspiration.

When clothed in firefighter gear and made to move in a hot environment, sensors can detect where the hot spots are.

Where the clothing is not allowing evaporation to occur or the heat to be released-- shown here in red.

And where heat is escaping more efficiently, cooling the body, shown in blue.

For Liz, her torso, chest, and hips are retaining the most heat.

♪ ♪ NARRATOR: To make protective garments specifically for the female form, the research team will need a whole new set of measurements to make new patterns.

One.

One, two... KWON: We're in the process of collecting anthropometric data on hopefully as many female firefighters as we can.

NARRATOR: Anthropometric data is information about the body's shape and proportions.

You're gonna do a front shot, then it's going to ask you to turn to the side... NARRATOR: The team is using three methods to collect the measurements.

SCANNER: Please move feet slightly further apart.

NARRATOR: First, a remote scanning application.

SCANNER: Well done.

Your body scan is complete.

NARRATOR: Second, a 3D scanner.

Finally, hand measurements for verification.

RESEARCHER: 33.2.

NARRATOR: They will turn the patterns into fire suit mockups.

KWON: Then, the next goal of our research is to develop those into wearable prototypes, which we then plan to pilot.

ADAM STELTZNER: Fabrics are one of the many things that are taken for granted in our modern life.

That this piece of fabric was engineered.

We think of it as a shirt.

Your t-shirt is engineered.

♪ ♪ NARRATOR: One major leap was the transition from natural fibers like silk and cotton to synthetics.

(sewing machine whirring) Before World War II, most parachutes were made of silk.

DAVIDSON: Silk is very light, but it's very strong.

That's why it was used for parachutes.

NARRATOR: But in 1935, a new textile was invented at DuPont, a chemical company.

So they developed this new material called a polyamide, which we now know as nylon.

(clicking) NARRATOR: Nylon, with other synthetics, eventually made it possible for us to walk on the moon.

And all along the way, women were helping us to reach greater and greater heights.

So, Sophia can come out now.

Think maybe some holes in... MCQUERRY: Having a group of women that really understand the female body is so important in the work that we're doing.

We all come at the problem with different perspectives, different backgrounds, different areas of expertise.

KWON: The other thing that really keeps us in it, is the enthusiasm of all the female firefighters.

Wow.

Yeah... KWON (voiceover): Because once they get it, they're like "Oh yes," you know, "Now I can actually speak up.

I can be heard and I can be acknowledged."

This scan looks like it came through really well.

(voiceover): It's an iterative process.

We are constantly going to have to make changes.

As we continue getting that out to the firefighting community, and, you know, and as long as there's some level of acceptance, I mean, we'll slowly be-- I think-- moving in the right direction of sort of implementing, you know, change for the better.

♪ ♪ (zipper sliding) NARRATOR: Woven fabrics can be engineered to protect here on earth.

But what about in one of the most challenging environments of all?

The harsh vacuum of outer space.

When crews first occupied the International Space Station in 2000, it marked the beginning of over 20 years of continual human residence in space.

But NASA plans to retire and de-orbit the station in the 2030s.

The hope is that it will be replaced, and then some.

MALIK THOMPSON: We're going back to space to stay.

We've proven that we can live in space for long periods in the International Space Station, and now we're pushing the envelope again.

♪ ♪ NARRATOR: A variety of companies are eager to join this new phase of space habitation, which holds promise for scientific breakthroughs.

LICAVOLI: It's really Sierra Space's mission to fill that gap, fill that void, have an opportunity to have a platform in space.

NARRATOR: NASA contracted Sierra Space to develop a new generation of inflatable habitats designed and built to allow humans to live and work in space, as well as on the moon, and eventually on Mars.

♪ ♪ The habitat is called LIFE, for Large Integrated Flexible Environment.

Today's engineering challenge is to destroy it.

BUCKLEY: We're at Marshall Space Flight Center.

For today's event, we're doing what's called an ultimate burst test.

We're going to take this article, and we're going to pressurize it until it fails.

Huge explosion, equal to 150 sticks of dynamite.

It's going to be epic.

HARRIS II: They are in the exciting process of watching their program intentionally fail.

(chuckles) They're in that learning mode where, you know, they go out and say, "we're going to blow this thing up."

NARRATOR: One unique feature of the LIFE habitat is that it can be compressed to fit into a single rocket's payload housing.

♪ ♪ And then inflated by a factor of six when deployed in space.

We have these goals of going to the moon, or going to Mars.

A lot of focus is being there.

Not everyone's thinking about actually living there.

And so this is where we start to fill in those gaps.

BUCKLEY: A LIFE article is 300 cubic meters.

We can put three floors inside this, have up to six people live inside this for months on months.

NARRATOR: At the core of the LIFE habitat's technology are what are known as soft goods: flexible, immensely strong materials that can be tightly packed down and then inflated.

(air hissing) The LIFE habitat is made up of four different layers, each with its own purpose, such as holding in air, providing insulation, and repelling dangerous micrometeorites, which can travel at tens of thousands of miles per hour and are common in outer space.

But the most critical layer of the LIFE habitat is the restraint layer, or primary structural shell, which the company is testing here.

The restraint layer is composed of hand-sewn pieces of fabric made of high-strength synthetic space-age material called Vectran.

BUCKLEY: Vectran is a chemically spun material made to be harder than steel.

So it comes in a thread, and then that thread is woven into a strap.

You could hang seven cars on this strap, and that strap would never break.

NARRATOR: Like so many modern technologies, at its core, the habitat and its Vectran webbing depend on age-old knowledge.

In this case, on the art and science of making baskets out of plant fibers.

BUCKLEY: When you're designing structural systems, you don't start from scratch, and basket weaving has been around for thousands of years, but we've applied it so you can use it in space.

NARRATOR: Today's test is crucial for assessing how the LIFE habitat manages the air pressure introduced in space.

At sea level on earth, the average air pressure is around 15 psi-- pounds per square inch.

That's the normal pressure that will fill the habitat.

However, the structure has to withstand significantly higher pressures to prevent any risk of a disastrous explosion.

That's where today's test comes in.

Humans are very... squishy, and they don't play well outside of their own environment, being Earth.

So when a new habitat is developed, a lot of intentionality goes into it, so that the human body is not exposed to things like radiation, extreme temperatures, lack of oxygen, and anything that could be flying around out there in space.

BUCKLEY: The LIFE habitat is following the NASA guidelines for operating pressure safety, which is a times four safety factor.

So we have a 15.2-psi operating pressure.

We times that by four, it gives us a 60.8.

NARRATOR: To reach the desired pressure of 60.8 psi, the habitat will be connected to air pumps regulated by valves controlling the flow of air.

The team will monitor the habitat's inflation from a control room more than a quarter mile away.

BUCKLEY: We have sensors on the top and the bottom of the article, which are going to give us what we call strain data.

All those thousands and thousands of data points, our analysts are going to take and take a look at it, so we can validate on Earth how our modules operate, along with validating it in space.

NARRATOR: Today's test will be the first ever of such a large inflatable structure.

Come on!

(man replies indistinctly) NARRATOR: But the team has already done several smaller burst tests.

BUCKLEY: You want to build articles fast, test, get that data.

(exploding) Prior to this, we did four articles, which gave us that data to catapult us and give us the confidence to go on to our first full-scale burst.

(blasting off) NARRATOR: Central to the habitat concept by NASA and Sierra Space is the vision that multiple structures can be sent into space gradually and linked together, like buildings along a city block.

Modularity is key to this concept.

If you have a modular design that you can configure any way you need to.

BUCKLEY: You're going to have a medical facility, you're going to have exercise, you're going to have a place for people to live, to enjoy themselves in space.

NARRATOR: As the team prepares for the evening's burst test, Beth Licavoli makes her final checks on the LIFE habitat's vast array of wires and sensors.

We're pretty much looking ready for burst.

NARRATOR: Safely watching from the control room, the team monitors the test in front of a dozen screens that will capture the burst.

BUCKLEY: So right now, we're inside the test room and we're taking a look at what is happening on the screens and we're preparing everything for the test.

(rumbling) Main site's been closed down, everything is good to go.

NARRATOR: The habitat sits out under the lights at one psi, but that soon changes.

JONAH BURGIN: We are pressurizing to 15 psi, for a five-minute hold.

LICAVOLI: Oh, you can hear it.

Yeah?

Go time.

Fill rate?

LICAVOLI: Uh, 3.06 psi per minute.

I'd expect... BURGIN: 35 psi, 35 psi.

All right.

All on the way to burst.

BUCKLEY: Here we go, let's do this.

LICAVOLI: All right.

NARRATOR: But about half an hour into the test, something is going wrong.

The flow of air has started to slow.

LICAVOLI: We're slowing down.

NARRATOR: But the team still hopes they can meet their goal.

BUCKLEY: Gotta hit 61.

BURGIN: Then call at 61?

Okay.

BUCKLEY: 61.

This is where it gets dicey.

BUCKLEY: Hear a little movement.

LICAVOLI: Come on, any second now.

61 psi, 61 psi.

(cheers and applause) Well done!

(clapping) Fantastic.

LICAVOLI: Let's keep going, though.

BUCKLEY: That is amazing.

NARRATOR: They've reached NASA's target psi, but the habitat is not filling as fast as expected.

BUCKLEY: Are we fighting it now?

BURGIN: Yeah, yep.

LICAVOLI: Oh my gosh, yeah.

NARRATOR: One potential explanation-- a leak.

That could be disastrous in space.

BUCKLEY: Are we still dropping?

LICAVOLI: Yeah.

NARRATOR: About an hour into the test, they decide to end it-- short of their ultimate goal.

BURGIN: R.O.V.

311 closed.

(team members confirm) TEAM MEMBER (over comms): R.O.V.

311 closed.

BUCKLEY: Close it, let it leak down.

NARRATOR: the lack of an explosion is a major disappointment.

Testing to failure is crucial to understanding the habitat's ability to withstand pressure.

After the habitat is depressurized and safe, the team gathers to determine the source of the leak.

TEAM MEMBER: All those straps want to be aligned with the bottom of the plate.

So there is nothing pushing on that bladder or doing anything like-- I would, I would highly doubt there's a leak right there.

Okay.

BUCKLEY: There's an air of excitement, and then there's air of like, "Aw, I wanted a big burst!"

Yeah, it's... You know, you want to take it to that failure.

LICAVOLI: This valve seems like our culprit.

We over-pressurized it.

NARRATOR: As air pressure built up in the valve, it overcame the force of the spring holding it closed, allowing air to escape.

BUCKLEY: When we found out that it was the valve, a little bit of a sense of relief, you know, knowing that the design of the structure was very viable.

NARRATOR: They decide to shut the problem valve off.

Fortunately, the remaining working valve is still able to inflate the habitat.

The following night, the group is back in the control room.

BURGIN: 25 psi, 25 psi.

BUCKLEY: Got our fill rate?

2922.

2922.

PSI per minute.

Ramp to burst.

TEAM MEMBER: Just keep going.

BURGIN: 55 psi.

Went better than last time.

BURGIN: 55 psi.

63 psi, 63 psi.

(room clapping) NARRATOR: They have reached the same pressure as the failed test the night before.

Keep going.

Going to burst.

NARRATOR: And it keeps rising.

BURGIN: 70 psi.

TEAM MEMBER: 70 psi... BURGIN: 75 psi.

76 psi.

This is insane.

I think I heard a little pop.

This is insane.

(loud burst) Oh!

(cheers and applause) (booming) (shaking) (booming, cheering continues) All right, high-fives, high-fives.

BUCKLEY: Well done, guys.

LICAVOLI: This is the first one that we could really feel the ground shake in this control room, which is incredible.

To see it, to really be here.

It's kind of surreal.

NARRATOR: And now they know the habitat's limit-- 77 psi.

BUCKLEY (voiceover): It was just an amazing moment.

It's one of those things you don't forget in your career, and you always talk about it.

(explosion roaring) NARRATOR: We're constantly on the move.

Expanding our reach upward, outward, and toward new horizons.

MABRY: Engineering is a process.

You take the baton and continue to engineer our world and to build things further, bigger, better, more efficient and more valuable.

The whole human experience, you could say, is an experiment in engineering of a society that's better, and that's why everything that we do is built upon what has been done in the past.

NARRATOR: Throughout history, we've never been content to stay put.

HARRIS II: Engineering is not a modern-day thing.

Engineering is something that expanded way into our past.

And I think it comes from curiosity, It comes from the need for survival.

One, two, three.

NARRATOR: As we continue building on what has come before, who knows what we'll innovate next.

ZILEVU: When we look at our lives, and we look at technology 100 years ago versus now, we couldn't imagine some of the things that we see today.

(booming) NARRATOR: "Building Stuff," to reach beyond.

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