the realm of spirits.

Modern science has linked these polar light shows, called auroras, to vast waves of electrified

gas hurled in our direction by the sun.

Today, researchers from a whole new generation see this dynamic substance, plasma, as an

energy source that may one day fuel humanity’s expansion into space.

What can we learn, and how far can we go, by tapping into the strange and elusive fourth

state of matter?

A

small cadre of scientists has come to Fairbanks, Alaska… to realize what may seem an impossible

dream… to revolutionize space travel.

Dr. Ben Longmier and his team from the University of Michigan have designed a whole new type

of rocket engine that promises a faster and more efficient way to get around in space.

They are here to test components of this rocket by sending them aboard helium balloons to

an altitude of 30 kilometers… into the harsh environment of space.

Above the north and south poles, conditions are about as harsh as you can get. Our planet

is bombarded with a steady steam of charged particles from the Sun.

Earth’s magnetic field accelerates and channels them, turning the night into a spectacle of

color.

While most astronauts train to live and work in zero gravity, or to move around in bulky

space suits, these would-be space explorers are preparing to negotiate some of Earth’s

harshest environments.

Once they launch their payload, it will rise slowly into the upper atmosphere.

After drifting through the night, above 99% of Earth’s atmosphere, the payload will

detach from the balloon and parachute down to the ground.

Where it goes and finally lands will depend on highly variable wind conditions. The team

must be prepared to retrieve it across a large stretch of Alaska’s snowy wilderness.

To understand the revolutionary nature of the idea they are pursuing, we go back to

the dawn of rocketry.

In over a hundred years, the technology of a rocket has hardly changed.

Fill a cylinder with volatile chemicals, then ignite them in a controlled explosion.

The force of the blast is what pushes the rocket up.

Nowadays, chemical rockets are the only ones with enough thrust to overcome Earth’s gravity

and carry a payload into orbit. But they are not very efficient.

The heavier the payload, the more fuel a rocket needs to lift it into space. But the more

fuel a rocket carries, the more fuel it needs.

One of the fabled Saturn V rockets of the Apollo era, for example, weighed in at 177,000

kilograms. Filled up with fuel, it weighed almost 16 times that.

The space shuttle, with maximum payload, weighed about 100 thousand kilos. Add tanks and fuel,

and it lifted off at 2 million kilograms.

Regardless of weight, for a spacecraft to escape Earth’s gravity and go into orbit,

it must reach a minimum speed of 40,000 kilometers per hour.

The energy needed to do that meant there wasn’t enough fuel for a sustained acceleration to

more distant planetary shores.

Most missions beyond Earth have relied instead on their initial launch speed to coast to

their destination.

The twin spacecraft of Voyager, for example, did not have enough speed to reach its current

position at the edge of the solar system.

To give them a boost, flight planners sent them into Jupiter’s gravitational field,

using its pull to sling shot them out to Saturn.

Voyager 2 got further assists from Saturn and Uranus. Voyager 1 used Saturn to accelerate

to almost 63,000 kilometers per hour.

Ben’s rockets promise far greater gas mileage than traditional chemical rockets, but with

enough power to reach distant targets more quickly.

The idea is that once in space, his rockets use electricity to create a weak force, which

over time can accelerate them to very high speeds.

They run on the same fuel that nature uses, literally, to power the cosmos.

Not long after its explosive beginnings, the universe was awash in vast stores of hydrogen

gas.

But even as the universe continued to expand, gravity drew clumps of matter into ever-denser

concentrations. The earliest stars took shape, immense balls of hydrogen gas, hundreds of

times the mass of our sun.

As they contracted inward, they heated up and ignited.

Intense radiation now began to flow through the voids. That had the effect, all through

the universe, of stripping electrons away from the primordial gas.

The universe became filled, not with solids, liquid, or gas, but with a fourth state of

matter: plasma.

On our planet, plasma occurs only in rare circumstances: in a hot flame, a bolt of lightning,

or in a blown electrical transformer.

Made up of negatively charged electrons and positively charged ions, plasma is in most

cases electrically neutral since the charges balance each other out.

That led the physicist Irving Langmuir in the 1920s to compare it to the clear liquid,

plasma, that carries blood cells through our bodies.

The development of radio led to the discovery, high above the Earth, of a natural plasma

ceiling, the ionosphere. It hovers above us, reflecting some radio frequencies and absorbing

others.

Its importance became clear when engineers noticed that radio waves could, under some

conditions, travel beyond our line of sight.

They discovered that signals could be bounced deliberately off this conducting layer, in

what’s called “skywave propagation.”

In World War 2, a whole new age of global communications came of age when radio was

used to execute complex worldwide logistics of troop and ship movements.

The presence of the ionosphere is due to a steady stream of charged particles, or plasma,

that comes from the sun.

A spacecraft with complex computer components must be able to survive constant exposure

to these particles.

As part of their design process, Ben and team want to test some of the specialized components

of their rockets in the plasma-fill environment of our upper atmosphere.

Those components will be mounted on a simple frame attached by rope to a high-altitude

balloon. The frame is also outfitted with an array of novel sensors to take independent

readings. One holds a colony of bacteria.

The idea is that the bacteria itself can detect radiation. So it mutates in a certain way

or in a very known way so that if you send it into an environment with a lot of cosmic

rays and perhaps a lot of x-rays from the aurora itself, it mutates. And so we’ll

detect sort of the level of radiation it’s exposed to by looking at these mutations after

we’ve recovered the baceria after flying them to the edge of space in one of these

balloon capsules.

Another is a series of tiny GoPro cameras converted to record the intensity of infrared

and ultraviolet light normally hidden to the human eye.

The team uses Argon gas to insulate instruments against the cold, with chemical packets added

for warmth.

They stabilize the frame with tiny gyroscopes, and outfit it with GPS devices for tracking.

This team is doing much more than just designing instruments to survive a rain of charged particles.

Their goal is to design spacecraft that actually harness the explosive properties of plasma.

Unlike most matter on Earth, plasma conducts electricity and responds to magnetic fields.

In space, these properties influence the formation of structures like galaxies and nebulae.

And they play a role in some of the most violent processes in the universe, such as the formation

of a black hole.

It forms in the wake of a giant star’s death, when matter collapses into its core. It swirls

in along what’s known as an accretion disk.

Magnetic fields take shape on the disk, rising and twisting around the polar regions. They

draw huge volumes of plasma up, then shoot it out at high speeds.

These plasma jets can extend far beyond the largest black holes. You can see them blasting

continuously from the centers of galaxies, reaching thousands of light years into space.

Studies of one giant nearby ball of plasma show what a complex and volatile substance

it can be.

In the core of our sun, high heat and crushing pressures cause hydrogen atoms to crash together.

That sets off a nuclear reaction in which hydrogen atoms fuse into heavier ones like

helium and carbon, generating heat.

This heat slowly rises to the surface of the sun in vast plumes of plasma.

You can see evidence of this process, called convection, in a pattern of ever-evolving

blobs known as granules. They are like the tops of thunderstorms.

Even as energy builds within, the sun's gravity and density can stifle its escape.

What carries it out are magnetic fields. They twist and wrap around, channeling energy to

the surface.

The fields can power immense loops of hot gas, about 60,000 degrees Celsius, then rise

up from the solar surface and fall back.

The largest eruptions, called coronal mass ejections, can reach up to 6 million miles

per hour as they hurtle out across the solar system.

They can literally slam into Earth’s own magnetic field.

Because solar particles are charged, a portion follows the orientation of Earth’s magnetic

field lines.

Finding an opening at the poles, these particles race down into the atmosphere.

You know this is happening when you see the beautiful lights of the aurora borealis in

the far north, or the aurora australis in the south.

They appear when charged solar particles collide with oxygen molecules in the upper atmosphere,

causing them to glow blue, red, and green depending on altitude.

Flying 350 kilometers above the earth, astronauts in the international space station watch in

awe as the aurora shimmers, framed by the glow of stars and cities at night.

Back in Michigan, Ben and his team have set up a lab to harness this strange substance

in a whole new generation of rocket engines.

The lab recalls an earlier period of space exploration.

It features a giant vacuum chamber, built in the 1960s in hopes of winning a contract

to test Apollo moon rovers.

The chamber has given this small university team the ability to accelerate their research

into the physics of plasma and rocket engine design.

They are actually part of an larger community of plasma rocket scientists… within NASA…

and within private companies like Ad Astra of Houston, Texas.

Because plasma does not occur naturally on Earth, the challenge is to create it, then

harness it.

The teams inject a gas, commonly argon, into a chamber. They bombard it with radio waves,

which strip electrons from the gas and turn it into a plasma.

The soup of electrons and ions accelerates as it moves through a magnetic field generated

by superconducting magnets. A second radio blast heats it up to a million degrees Celsius.

That’s enough to blast it out and propel a spacecraft.

The idea of using plasma to power rockets is not a new one.

The Polish physicist Stanislav Ulam is said to have been inspired by atom bomb tests in the

1940s. He speculated that waves of plasma from small nuclear detonations could propel

a spacecraft to extreme speeds.

In the 1950s, that idea animated dreams of exploring the solar system in spacecraft like

this 360-ton Mars-bound vehicle.

The idea gained funding in the Orion project, with the idea of driving a spacecraft with

nuclear pulses and landing on Mars in only a month. Concerns about radioactive exhaust

helped doom the project.

Plasma rockets, energized by nuclear reactions, were revived in the Daedalus and Nerva projects

of the 1960s, and again at the beginning of this century as part of a proposed journey

to Jupiter’s moon Europa. Rising costs killed that mission.

Newer plasma rocket concepts have switched to solar energy to power their engines.

Among the most ambitious, the DAWN mission was sent into orbit aboard a Delta 2 rocket

in the year 2007. It then headed out on a ten year mission to the asteroid belt.

It uses only about 10 ounces of xenon gas fuel per day. With engines designed to fire

for over 2000 days, over time it is expected to gain an additional 38,000 kilometers per

hour.

After a gravity assist from Mars, Dawn arrived at the asteroid Vesta in 2011.

It spent a year mapping its surface and seeking clues to its interior structure.

Now headed for Ceres, a dwarf planet located within the asteroid belt, Dawn will be the

first probe ever visit.

Made up of rock and ice, Ceres may well have an internal ocean of water and ice. It takes

us back to the formation of the solar system, when objects like this grew and developed

into planets.

Long range missions like Dawn are just one of many uses for plasma rockets.

So nasa launches spacecraft with ion engines and hall thrusters on board. Almost every

new geostationary satellite that a company will invest in and put up in orbit will have

some sort of electric propulsion device on board to do station keeping, to do little

changes in attitude and maneuvers to keep it in its geostationary orbit.

NASA is planning to use a plasma rocket to do some even heavier lifting, as early as

2016.

Flying at an altitude of three hundred fifty kilometers, the International Space Station

whips around the Earth every one and a half hours.

To stay aloft, it must maintain a speed of 28,000 kilometers per hour. But its solar

panels and crew modules smack into so many tiny molecules in the upper atmosphere that

it gradually slows down and loses altitude.

To stay aloft, the station uses up around 4,000 kilograms of fuel per year. That fuel

must be flown up from Earth, which in turn reduces the amount of food, water, people,

and equipment that a resupply mission can deliver.

The idea is to use a plasma rocket to help boost the station to a higher altitude, powered

by electricity generated by solar panels aboard the station.