Activa JavaScript para disfrutar de los vídeos de la Mediateca.
Destination Tomorrow - DT15 - New Materials
Ajuste de pantallaEl ajuste de pantalla se aprecia al ver el vídeo en pantalla completa. Elige la presentación que más te guste:
NASA Destination Tomorrow Segment exploring new materials technology development and how it has revolutionized the world of science and technology.
Researchers at NASA have a long and significant history of materials technology development.
00:00:00
With an impressive list of new lubricants, lightweight alloys, and composites,
00:00:05
these materials have revolutionized our world.
00:00:09
Since the 1960s, the process of creating new materials has rapidly advanced.
00:00:12
Today, NASA scientists are continuing to develop new materials
00:00:17
that are hundreds of times stronger than steel at a fraction of the weight.
00:00:21
These advanced materials are becoming so strong and lightweight,
00:00:25
they can stop bullets and even keep debris from puncturing space vehicles.
00:00:28
But how are these materials made and what else can they be used for?
00:00:33
Our own Johnny Alonzo finds out how it works.
00:00:36
Specialized protective clothing has been around for thousands of years.
00:00:45
From ancient warriors to medieval knights,
00:00:48
protective garments were worn to help prevent injuries and save lives.
00:00:50
The materials that were used to make these types of clothing, like metal and leather,
00:00:54
worked well in those early days.
00:00:57
But as weapons became more sophisticated,
00:00:59
the usual materials began offering less protection.
00:01:01
The types of materials that were used to make protective clothing
00:01:04
remained relatively unchanged until about the mid-1960s
00:01:07
when a research scientist named Stephanie Qualic
00:01:10
introduced a revolutionary new material called Kevlar.
00:01:12
This material was not only lightweight and durable,
00:01:15
but was about five times stronger ounce for ounce than steel.
00:01:17
With this development, the world of protective materials changed forever.
00:01:21
Today, stronger, lighter synthetic structures have opened up new and exciting avenues
00:01:25
in the development of protective materials.
00:01:29
These materials are being used in everything,
00:01:31
from sporting goods to space applications.
00:01:33
To help shed some light on how these materials have changed our lives,
00:01:36
I spoke with Dr. Jeffrey Hinckley at NASA Langley Research Center
00:01:38
to find out how it works.
00:01:41
If you look at the history of materials in humankind,
00:01:44
you see the Stone Age, the Bronze Age,
00:01:46
and then the Age of Steel, which is sort of the Industrial Revolution.
00:01:49
We're in the course of another revolution now,
00:01:53
of high-performance materials that combine the strength,
00:01:55
the stiffness of steel with other properties,
00:01:58
electrical conductivity, the ability to be formed plastically,
00:02:00
and to even stop bullets.
00:02:05
Another example is Kevlar, which is used in armor protection for our troops.
00:02:08
And, of course, glass fiber is familiar to some people,
00:02:12
and glass fiber boats, and so on.
00:02:15
So we've talked about Kevlar.
00:02:17
How does a thin material like that stop bullets?
00:02:19
You have here the flexibility of a fine fiber,
00:02:22
a very tough, resilient material,
00:02:25
and twice as strong as steel at a fifth the weight.
00:02:27
And Kevlar is also a good material for penetration resistance, cut resistance.
00:02:30
Because of the way it's fabricated, actually,
00:02:37
the molecules that make up the polymer are stretched and aligned
00:02:39
such that in order to break this material,
00:02:44
you actually have to break the molecules.
00:02:46
To understand how a flexible material like Kevlar can stop bullets,
00:02:48
just think of a net on a soccer goal.
00:02:51
The net strands are interlaced together,
00:02:53
which are in turn attached to the frame of the goal.
00:02:55
When the ball is kicked into the goal,
00:02:57
each tether extends from one side of the frame to the other,
00:02:59
dispersing the energy from the point of impact over a wide area.
00:03:01
This forces the ball to stop.
00:03:05
The same basic principle applies to bulletproof vests.
00:03:07
The vest is made up of layers of fabric containing incredibly strong fibers.
00:03:10
When a bullet hits this material, the energy is dissipated,
00:03:14
forcing it to stop before it can penetrate the vest.
00:03:17
Why is NASA interested in using these materials?
00:03:20
Kevlar, as a bulletproof vest material,
00:03:23
is essential to protecting the astronauts and the equipment,
00:03:26
for example, on the space station.
00:03:29
Space is a very hostile environment.
00:03:31
Extreme temperatures, radiation, and small meteorites
00:03:34
can make working there very dangerous.
00:03:37
For example, the International Space Station
00:03:39
is orbiting the Earth at close to 18,000 miles per hour.
00:03:41
At these speeds, even a piece of debris the size of a grain of sand
00:03:44
can damage the station.
00:03:47
To help decrease the chance of an object penetrating the outer skin,
00:03:49
the space station wears a type of bulletproof vest.
00:03:52
Layers of aluminum, ceramic fabrics, and Kevlar
00:03:55
form a blanket around each module's aluminum shell.
00:03:58
If an object strikes the station,
00:04:01
this blanket of protective materials helps to dissipate the energy of the object,
00:04:03
helping to keep the crew safe inside.
00:04:07
I know that composite materials are still relatively new.
00:04:09
How do you think they will change in the future?
00:04:12
Maybe one of the most exciting examples is carbon nanotubes.
00:04:15
These are pure carbon and unbelievably small,
00:04:19
but they're in the form of a fiber.
00:04:24
This is a material that was discovered in the 1990s
00:04:27
and is probably stronger than anything we've known up till now.
00:04:30
It's perhaps stronger than diamond.
00:04:35
The trick is to figure out how to make something useful
00:04:38
out of these tiny, tiny tubes.
00:04:41
This is 10,000 times smaller than the human hair.
00:04:43
And so the trick is to use this material,
00:04:47
which even under a microscope just looks like soot,
00:04:50
into a strong, lightweight composite material.
00:04:54
And so our chemists are working on that.
00:04:59
An idea that's really on the drawing boards
00:05:02
is the idea of a self-healing material.
00:05:05
You can imagine a spacecraft that's going to be in orbit for 20 years.
00:05:07
It would be nice not to have to service it.
00:05:10
So we conceived the idea of a material
00:05:12
that would heal itself after it was damaged.
00:05:16
And I have an example here.
00:05:19
This is sort of a conventional plastic material
00:05:22
that was struck by a 9-millimeter bullet.
00:05:25
And as you can see, it shattered and left a hole
00:05:29
that's just a little over 9 millimeters in diameter.
00:05:32
Here's a new material that was invented here at NASA.
00:05:36
And this also was struck by a 9-millimeter bullet.
00:05:39
The bullet went right through.
00:05:43
The bullet was not stopped.
00:05:45
But there's no hole.
00:05:47
We can imagine that self-healing materials
00:05:49
would be useful on aircraft, too.
00:05:51
Right now, when an aircraft is brought in for service,
00:05:53
they look all around it for cracks.
00:05:56
And they're looking for a critical crack,
00:05:58
which on some commercial jets
00:06:00
might be as much as 4 inches long.
00:06:02
When they get to the critical crack size, they repair it.
00:06:04
We can imagine a composite material
00:06:07
made with self-healing matrix, self-healing plastic,
00:06:09
that could heal itself, and the cracks would never grow.
00:06:12
The exciting thing about working for NASA
00:06:16
is that it is always something new.
00:06:18
And we get to sometimes see the results of our work
00:06:20
coming into commercial use.
00:06:23
So the next time you hear about somebody
00:06:25
getting their life saved by a bulletproof vest,
00:06:27
you know how it works.
00:06:29
I wonder if these things work well with paintballs.
00:06:31
- Valoración:
- Eres el primero. Inicia sesión para valorar el vídeo.
- 1
- 2
- 3
- 4
- 5
- Idioma/s:
- Niveles educativos:
- ▼ Mostrar / ocultar niveles
- Nivel Intermedio
- Autor/es:
- NASA LaRC Office of Education
- Subido por:
- EducaMadrid
- Licencia:
- Reconocimiento - No comercial - Sin obra derivada
- Visualizaciones:
- 555
- Fecha:
- 28 de mayo de 2007 - 17:05
- Visibilidad:
- Público
- Enlace Relacionado:
- NASAs center for distance learning
- Duración:
- 06′ 33″
- Relación de aspecto:
- 4:3 Hasta 2009 fue el estándar utilizado en la televisión PAL; muchas pantallas de ordenador y televisores usan este estándar, erróneamente llamado cuadrado, cuando en la realidad es rectangular o wide.
- Resolución:
- 480x360 píxeles
- Tamaño:
- 38.17 MBytes