Last September, a few hundred scientists, engineers and space enthusiasts gathered at the Hyatt Hotel in downtown Houston for the second public meeting of 100 Year Starship. The group is run by former astronaut Mae Jemison and funded by DARPA. Its mission is to "make the capability of human travel beyond our solar system to another star a reality within the next 100 years."
For most of the attendees at the conference, advances in manned space exploration have been frustratingly slow in coming. Despite billions of dollars spent over the last few decades, space agencies aren't capable of much more than they were in the 1960s. They may be capable of less. 100 Year Starship intends to accelerate the process of interstellar travel by identifying and developing promising technologies.
Over the course of several days, attendees could join symposia on such exotic topics as organ regeneration and organized religion aboard a starship. One of the most anticipated presentations was titled "Warp Field Mechanics 102," given by Harold "Sonny" White of NASA. A nine-year agency veteran, White runs the advanced propulsion program at Johnson Space Center (JSC), down the road from the Hyatt. Along with five others, he recently co-authored the agency's 16-year "In-Space Propulsion Systems Roadmap," which outlines NASA's goals for the future of space travel. The plan calls for all manner of propulsion projects from improved chemical rockets to far-forward systems like antimatter and nuclear engines. White's particular area of research is perhaps the most far-forward of them all: warp drive.
Put plainly, warp drive would permit faster-than-light travel. It is, most assume, impossible, a clear violation of Einstein's theory of general relativity. White says otherwise. For half an hour at the symposium, he outlined the physics of a potential warp drive—walking attendees through things like Alcubierre bubbles and hyperspace oscillations. He explained how he'd recently computed theoretical results that could pave the way for an actual warp drive and that he was commencing physical tests in his NASA lab, which he calls Eagleworks.
It almost goes without saying that functional warp drive would have tremendous implications for space travel. It would free explorers not only from Earth's orbit, but from the entire solar system. Instead of taking 75,000 years to get to Alpha Centauri, the star system nearest to our own, warp-equipped astronauts, White says, could make the trip in two weeks.
In the wake of the shuttle program's termination and given the increasing role of private industry in low-Earth orbit flights, NASA has said it will refocus on far-flung, audacious exploration, reaching far beyond the rather provincial boundary of the moon. But it can only reach those goals if it develops new propulsion systems—the faster the better. A few days after the 100 Year Starship gathering, the head of NASA, Charles Bolden, echoed White's remarks. "One of these days, we want to get to warp speed," he said. "We want to go faster than the speed of light, and we don't want to stop at Mars."
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The first mainstream use of the expression "warp drive" dates to 1966, when Gene Roddenberry launched Star Trek. For the next 30 years, warp existed purely as a construct of one of science fiction's most enduring series. Then, a physicist named Miguel Alcubierre found himself watching an episode of the show. At the time, he was doing his graduate work in general relativity, and he asked himself what it would take to make warp drive physically plausible. He published a paper outlining the physics in 1994.
Alcubierre envisioned a bubble in space. At the front of the bubble, space-time would contract, while behind the bubble, space-time would expand (somewhat like in the big bang). The deformations would push the craft along smoothly, as if it were surfing on a wave, despite the tumult around it. In principle, a warp bubble could move along arbitrarily quickly; the speed-of-light limitation of Einstein's theory applies only within space-time, not to distortions of space-time itself. Within the bubble, Alcubierre predicted that space-time would not change, leaving space travelers unharmed.
Warp drive would free explorers not only from Earth's Orbit, but from the entire Solar System.
Einstein's equations of general relativity are very difficult to solve in one direction—figuring out how matter bends space—but going backward is fairly easy. Using them, Alcubierre determined the distribution of matter necessary to create such a warp bubble. The trouble was, the solutions called for an obscure form of matter called negative energy.
In the most basic of definitions, gravity is the attractive force between two objects. Every object, no matter how small, exerts some attractive force on surrounding matter. Einstein's insight was that this force is a curvature in space-time. Negative energy, though, is gravitationally repulsive. Instead of drawing space-time together, negative energy would push it apart. Roughly speaking, for his model to work, Alcubierre needed negative energy to expand the space-time behind a craft.
Though no one has ever measured negative energy, quantum mechanics predicts that it exists, and scientists should be able to create it in a lab. One way to generate it would be through the Casimir effect: Two parallel conducting plates, placed very closely together, should create small amounts of negative energy. Where Alcubierre's model broke down is that it required a vast amount of negative energy, orders of magnitude more than most scientists estimate could be produced.
White says he's found a way around that limitation. In a computer simulation, White varied the strength and geometry of a warp field. He determined that, in theory, he could produce a warp bubble using millions of times less negative energy than Alcubierre predicted and perhaps little enough that a space craft could carry the means of producing it. "The findings," he says, "change it from impractical to plausible."
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Johnson Space Center sprawls beside lagoons where Houston gives way to Galveston Bay. It has the feel of a suburban college campus, albeit one geared to the training of astronauts. The day I visit, White meets me in Building 15, the low-rise warren of hallways, offices, and labs that contains Eagleworks. He is wearing a polo shirt embroidered with the Eagleworks emblem, which depicts an eagle, mid-swoop, soaring over a futuristic starship.
White did not start his career in propulsion. He studied mechanical engineering, and he joined the agency in 2004 as part of its robotics group, having worked at JSC as a contractor since 2000. Eventually, he took command of the robot arm on the International Space Station while working on a Ph.D. in plasma physics. It was only in 2009 that he shifted his responsibility to propulsion, which had been a long-standing interest of his and the reason he came to work for NASA in the first place.
"Sonny is a pretty unique person," says his boss John Applewhite, who heads the Propulsion Systems Branch within the JSC engineering directorate. "He's definitely a visionary, but he's also an engineer. He can take his vision and turn it into a useful engineering product." About the time he joined Applewhite's group, White requested permission to open his own lab, dedicated to advanced propulsion. He dreamed up the name Eagleworks—a patriotic riff on the famous Lockheed Martin Skunk Works—and had NASA create a logo to his specifications. Then he got to work.
White leads me to his office, which he shares with a colleague who is looking for water on the moon and then takes me down the hall to Eagleworks. As we walk, he tells me about his quest to open the lab, which he frames as "a long arduous process of trying to find ways for advanced propulsion to help human space exploration." He speaks with a slight drawl, a product of many years spent in the South—first at college in Alabama and then 13 years in Texas.
White shows me into the facility and ushers me past its central feature, something he calls a quantum vacuum plasma thruster (QVPT). The device looks like a large red velvet doughnut with wires tightly wound around a core, and it's one of two initiatives Eagleworks is pursuing, along with warp drive. It's also secret. When I ask about it, White tells me he can't disclose anything other than that the technology is further along than warp drive. A 2011 NASA report he wrote says it uses quantum fluctuations in empty space as a fuel source, so that a spaceship propelled by a QVPT would not require propellant.
White's warp experiment is tucked into the back corner of the room. A helium-neon laser is bolted onto a small table pricked with a lattice of holes, along with a beam splitter and a black-and-white commercial CCD camera. This is a White-Juday warp field interferometer, which White named for himself and Richard Juday, a retired JSC employee who is helping White analyze the data from the CCD. Half of the laser light passes through a ring—White's test device. The other half does not. If the ring has no effect, White would expect one type of signal at the CCD. If it warps space, he says "the interference pattern will be starkly different."
When the device is turned on, White's setup looks cinematically perfect: The laser is bright red, and the two beams cross like light sabers. There are four ceramic capacitors made of barium titanate inside the ring, which White charges to 23,000 volts. White has spent the last year and a half designing the experiment, and he says that the capacitors will "establish a very large potential energy." Yet when I ask how it would create the negative energy necessary to warp space-time he becomes evasive. "That gets into . . . I can tell you what I can tell you. I can't tell you what I can't tell you," he says. He explains that he has signed nondisclosure agreements that prevent him from revealing the particulars. I ask with whom he has the agreements. He says, "People come in and want to talk about some things. I just can't go into any more detail than that."
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While the theory of warp travel is intuitive enough—deform space-time to create a moving bubble—it suffers from a few significant obstacles. Even if White can drastically reduce the amount of negative energy that Alcubierre required, it may still be much more than scientists can produce, says Lawrence Ford, a theoretical physicist at Tufts University who has published dozens of journal articles on negative energy over the last 30 years. Ford and other physicists say there are fundamental physical limitations—not just engineering challenges—on the amount of negative energy that can exist in one place for any length of time.
Another challenge is that in order to create a warp bubble that moves faster than light, scientists would need to distribute negative energy around a craft, including ahead of it. White doesn't think this is a problem; when I ask him about it, he says rather vaguely that a warp drive would work because of an "apparatus you have that's creating the conditions that you need." But creating those conditions in front of a ship would mean generating a distribution of negative energy that travels faster than light, a violation of the theory of general relativity.
In saying that a warp drive is feasible, White is also saying that he can create a time machine.
Finally, warp drive poses a conceptual problem. In general relativity, faster-than-light travel is equivalent to moving about in time. In saying that a warp drive is feasible, White is also saying that he can create a time machine.
Those obstacles raise some significant doubts. "I don't think any normal understanding of physics predicts he's going to see anything in his experiments," says Ken Olum, a physicist at Tufts University, who served on a panel debating exotic propulsion at the 100 Year Starship gathering in 2011. Noah Graham, a physicist at Middlebury College who read two of White's papers at my request, wrote in an e-mail: "I don't see any valid science in either paper beyond the summaries of previous work."
Alcubierre, now a physicist at the National Autonomous University of Mexico, is also doubtful. "Even if I'm in a spaceship in the middle and I have the negative energy, there's no way I can put it where I need it," he told me by phone from his home in Mexico City. "It's a nice idea. I like it because I wrote it myself. But it has a series of limitations that I've seen through the years, and I don't see how to fix them."
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To the left of the main gate at Johnson, a Saturn V rocket lies on its side, its stages disconnected to show some of its guts. It's massive. Just one of its many engines is nearly the size of a small car, and, laid on end, the rocket is a few feet longer than a football field. It is a quiet testament to the difficulty of space travel. It is also four decades old, and the time it represents—when NASA was part of a grand national effort to send a man to the moon—has long passed. Today, JSC feels like a place that once touched greatness but has since fallen from its orbit.
A breakthrough in propulsion could spell a new age at JSC and NASA, and to a degree that age is already upon us. Dawn, a probe launched in 2007, is exploring the asteroid belt using ion thrusters. In 2010, a Japanese team deployed Ikaros, the first interplanetary craft driven by a solar sail, another type of experimental propulsion. And in 2016, scientists plan to test VASIMR, a plasma-based system designed for high-thrust propulsion, on the ISS. While those systems might one day carry astronauts to Mars, they still will not be able to send astronauts beyond the solar system. To do that, White says NASA will need to embrace riskier projects.
Warp drive is perhaps the most far-fetched of all NASA's propulsion efforts. The greater scientific community says White cannot create it. Experts say he's working against the laws of nature and physics. Nonetheless, NASA is behind it. "He's not funded at a very high level in terms of what he's trying to accomplish," Applewhite says. "I think there's very much interest within the directorate to continue growing his work. These are the kinds of theoretical concepts that, if they come to fruition, would be game changers."
In January, White packed up his warp interferometer and moved it to a new facility. Eagleworks had outgrown its first home. The new lab is larger and, he says enthusiastically, "It's seismically isolated," meaning it is shielded from vibrations. But perhaps the best thing about the new lab is also the most telling. NASA assigned White to a facility that was built for the Apollo program, the same one that put Neil Armstrong and Buzz Aldrin on the moon.
Konstantin Kakaes is a Schwartz fellow at the New America Foundation.
This article appeared in the April 2013 issue of Popular Science Magazine.