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Star Trek Science: Here comes the Impulse Engine!

Star Trek fans take note: Have a seat before you read the next sentence or prepare to swoon.

University of Alabama-Huntsville (UAH) aerospace engineers working with NASA, Boeing and Oak Ridge National Laboratory are investigating how to build fusion impulse rocket engines for extremely high-speed space travel.

“Star Trek fans love it, especially when we call the concept an impulse drive, which is what it is,” says team member Ross Cortez, an aerospace engineering Ph.D. candidate at UAH’s Aerophysics Research Center.

Stay seated Trekkies, because there’s more.

“The fusion fuel we’re focusing on is deuterium [a stable isotope of hydrogen] and Li6 [a stable isotope of the metal lithium] in a crystal structure. That’s basically dilithium crystals we’re using,” Cortez says, referring to the real-world equivalent of the fictional element used to power Star Trek’s Starship Enterprise.

While this engine, if produced, wouldn’t generate a fraction of the velocity as the faster-than-light warp drives envisioned in the TV shows, books and movies, it could produce speeds that exceed other not-science-fiction-based systems that rocket scientists are investigating.

Their ultimate goal is to develop a nuclear fusion propulsion system by 2030 that can spirit spacecraft from Earth to Mars in around three months—about twice as fast as researchers think they could go with a nuclear fission engine, another scheme that is being investigated but has not yet been built.

Their current design has a spacecraft with the impulse engines being built in low Earth orbit, so the thrusters and ship wouldn’t need to cope with the atmosphere or achieving escape velocity. That doesn’t mean it would be a lightweight when fully assembled, though. Cortez says the craft could tip the scales at almost 500 tons.

Major problems to solve

There’s a big gap between hopes and goals, though. For decades, nuclear fusion researchers have worked to harness the huge amounts of energy generated from slamming atoms together so hard they fuse. Their efforts have led to scientific progress, but the goal of getting more energy out of a fusion reaction than what is required to smash them together at amazingly high speeds has so far proven elusive.

Last week, Sandia National Laboratory investigators said they are getting closer to “break-even,” the holy grail of research that will see the same amount or more energy released from a nuclear fusion reaction than that which was put in.

“We’re interested in deep-space exploration,” says Dr. Jason Cassibry, a UAH engineering professor and the head of the research team. “Right now humans are stuck in low Earth orbit, but we want to explore the solar system. We’re trying to come up with a system that will demonstrate break-even for thermonuclear propulsion.”

To really start getting around the solar system, spacecraft will need to go much faster than they do now.

According to astronomy professor Courtney Seligman, the next date Earth will be closest to Mars after the team’s 2030 objective will be in May 2031, when the two planets will be 51.4 million miles apart. For the team’s fusion-powered spacecraft to reach the red planet in three months at that point, it would have to travel at almost 24,000 miles per hour, or about 10 times the muzzle velocity of a bullet fired from an assault rifle.

(conceptual diagram of the team’s fusion impulse engine. Image courtesy Ross Cortez/UAH)

Z-pinch fusion and magnetic nozzles

To hit this phenomenal speed, the researchers are investigating something called z-pinch fusion as a source of propulsion. Cortez says the technique takes a cylindrical array of super-thin lithium wires and puts a massive electric current through them. The electricity—millions of amps are being sent through the wires in 100 nanosecond pulses, which could produce 3 terawatts of output power—creates a magnetic field around the array and vaporizes the wires to form plasma. The magnetic field pinches the plasma until it collapses on a core of deuterium and lithium, which they hope will cause its atoms to fuse and result in a massive release of energy.

“What we’re aiming for is to get enough compression and heat in the z-pinch implosion to cause the fusion fuel to react,” Cortez says. “With the energy that would release, we could get millions of pounds of thrust out the back of this thing—on the order of Saturn-V-class thrust.”

After achieving the proper speed, the engines would be shut down and the craft would coast to its target.

Besides figuring out the fusion problem, another obstacle to their goal is how to contain and direct the resulting energy to generate thrust—no small task because the reaction would create temperatures in the millions of degrees Celsius, enough to vaporize any known material. To solve this problem, part of the team is working on another line of research, which seeks to develop a “magnetic nozzle.” This would use directed magnetic fields to guide the energy out of the engine.

“We’re facing some pretty heavy problems to getting this thing working; it won’t be a cinch,” Cortez says. “But we’re very ambitious and we’ve got a lot of great ideas. Put enough bright people to work on it and you’re going to get gold or, in this case, fusion.”

But even if they don’t reach their objective of developing the z-pinch fusion propulsion system, the group’s work will likely be useful in the global effort to develop terrestrial fusion reactors as a source of clean, limitless energy.

The major hurdles have not yet shaken Cortez’s optimism, because he keeps thinking of what success might mean: “How could I not stay interested? With this work, eventually, I might have the chance of seeing Jupiter up close or help humanity colonize Mars.”

(UAH doctoral candidate Ross Cortez assembles a device that generates massive bursts of electricity for fusion propulsion research.)

Top Image: A conceptual model of the University of Alabama-Huntsville’s fusion impulse propulsion spacecraft. Courtesy Ross Cortez/UAH.

Michael Keller is the Managing Editor of Txchnologist. His science, technology and international reporting work has appeared online and in newspapers, magazines and books, including the graphic novel Charles Darwin’s On the Origin of Species. Reach him at mkeller@groupsjr.com.

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Shape Shifters on the way? Next up: Klingon Cloaking Device!

Michio Kaku: Shape-Shifting Technology Is Coming
Big Think Editors on October 12, 2010, 12:00 AM

Physicist and Big Think blogger Michio Kaku is the closest thing the world has to real-life wizard. With his shocking white hair, he makes prophesies about fantastic technologies that science is close to unlocking. On “The Colbert Report” this summer, for instance, Kaku said that we would soon have invisibility cloaks like in the “Harry Potter” books.

During his most recent Big Think interview, we asked Dr. Kaku what other futuristic technologies we could hope to see within our lifetimes. His answer: shape-shifting. Science is already making huge advances in so-called “programmable matter,” he says. “Atoms can slide over atoms, rearrange themselves, but what happens if atoms are replaced by chips, chips that are so small they’re smaller than the head of a pin and you can change their electric charge? By changing the electric charge they bind and reform in different ways and they’re intelligent because each dot is a computer chip perhaps as powerful as a PC.” This may sound like science fiction, but the computer chip manufacturer Intel is already leading the charge toward developing this kind of programmable matter. In the future it could be used to build entire cities instantaneously. “If I have a clump of clay made of thousands of millions of little dots I push a button then the charges rearrange themselves to form a statue, a car, whatever you want,” Kaku says. “This means that I can push another button and this clay turns into a house or I push another button and a whole city rises out of the desert.”

Kaku also discussed the prospect of a technological singularity, a point at which robots will become smarter than humans—resulting in explosive scientific innovation. Based on Moore’s Law, which says that computer technology doubles every 18 months, some have projected that the singularity will take place as soon as 2029. But Kaku calls these predictions inaccurate because at some point Moore’s Law will hit a wall. There will be a point at which silicon transistors will physically not be able to get smaller or more powerful, he says. Scientists will need to find a replacement for silicon if computers will continue to improve. And even if scientists do overcome this, Kaku isn’t too worried that robots will take over and enslave us. “Right now our machines are as smart as insects,” he says. “Probably by the end of the century, who knows, they’ll be as smart as monkeys. At that point they could become potentially dangerous because monkeys can formulate their own plans; they don’t have to listen to you. They can formulate their own strategies, their own goals and I would say therefore at that point let’s put a chip in their brain to shut them off if they get murderous thoughts.”

But robots aren’t the only thing that could destroy mankind. We are more than capable of doing that job ourselves, he says. And what happens over the next 100 years will determine the fate of mankind. Kaku says we are currently a “type zero” civilization; we rely on fossil fuels and have nationalistic governments. But in about 100 years we will become a “type one” civilization, a planetary civilization with global governments and institutions. “We’ll be able to harness all the energy output of the planet earth,” he says. “We’ll play with the weather, earthquakes, volcanoes. Anything planetary we will play with.” And this formative next century is so dangerous because we still have sectarian, fundamentalist ideas circulating alongside nuclear, chemical, and biological weapons that could wipe life off the planet. Terrorists are a reaction against a type one civilization, which is beginning to emerge with organizations like the European Union and a global language like English. “What they’re reacting to is the fact that we’re headed toward a multicultural tolerant scientific society and that is what they don’t want. They don’t want science. They want a theocracy. They don’t want multiculturalism. They want monoculturalism.”

Michio Kaku talks Time Travel

“I would like to see . . . when we have a theory of everything.”

If Time Were Really on His Side, Michio Kaku Would Go From the Big Bang to the Big Picture

Michio Kaku is the co-founder of 11-dimensional “string theory,” which is either a Nobel-worthy “theory of everything” or unverifiable poppycock, depending on whom you talk to. His latest best-selling work is “Physics of the Impossible.”

— Joel Garreau

You describe time travel as a “Class II Impossibility” — at the very edge of our understanding of the physical world. But then you mention that physicists are unable to find any physical law that makes time travel impossible. What are the top three times you’d want to go to and why?

I think every physicist would like to witness the instant of creation. The Big Bang. Normally we’d like to do this from a safe distance.

But there isn’t one.

That’s a problem, right. Because the universe was quite small back then, and if we were inside the universe, we too would be quite small. And we too would be bathed by an enormous flux of radiation. But assume for a moment that it is possible to look at it from another dimension. That would give us a bonanza of information about the nature of the universe. Now if I had a second choice, I would like to meet Isaac Newton at the height of his creative powers.

Did the apple tree exist?

We do think that when he was 23 years old he saw an apple fall, and then he asked the key question — if an apple falls, does the moon also fall? And he came to the conclusion yes — the moon is in free-fall. And then you could calculate the motion of the moon using his new law of gravity. That’s what he did when he was in his 40s. In about 18 months, in one of the greatest outpourings of intellectual genius the world has ever seen, he wrote down “Principia” — basically the laws of the planets.

Now, a third thing, if I could, I would like to see beyond my years, maybe like 100 years in the future, when we have a theory of everything. This is my life’s work, right?

What you basically want to know is whether you’re Einstein.

Well, we want to know whether we wasted some of the best years of our life, okay?

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