After several decades of slow progress, NASA appears to be on the verge of a quantum leap in propulsion that could cut travel times for space probes and manned missions to a fraction of their present duration.
The new propulsion system involves a controlled reaction of matter and anti-matter. Dr. Zefram Cochrane, head of NASA's Jet Propulsion Laboratory at California Institute of Technology, states that the technology, initially considered too dangerous for manned flight, has progressed much more quickly than expected, and has resulted in power levels considerably greater than initially projected.
"We were uncertain whether we could control an anti-matter reaction at first," Cochrane said. "There are no known substances which can withstand the heat of the reaction. What we were able to do was to create an positronic energy field to contain the reaction. The containment field draws energy from a nuclear reactor at first, but once the matter-antimatter reaction is underway, the energy for the containment field is drawn directly from the reaction."
What may be of special interest to environmentalists is the waste product of the reaction: nothing. The matter-antimatter reaction results in the total destruction of the particles, which are completely converted to energy in accordance with Einstein's equation. What Einstein was unable to predict, according to Cochrane, was that the tremendous amount of energy produced makes possible travel speeds that seemed like science fiction just a few years ago.
"We plan on retro-fitting the Constellation vehicles with the new propulsion system,' Cochrane said. "When we first went to the moon, it took five days. The return trip should be, like, three minutes. Mars will be about a half-hour."
Cochrane said that the controlled matter-antimatter reaction produces sufficient energy to make deeper space travel possible. Speeds faster than light could result from an Alcubierre-effect warping of the space-time continuum.
In 1994, the Mexican physicist Miguel Alcubierre proposed in the Journal of Classical and Quantum Gravity a method of stretching space in a wave which would in theory cause the fabric of space ahead of a spacecraft to contract and the space behind it to expand. The ship would ride this wave inside a region known as a warp bubble of flat space. Since the ship is not moving within this bubble, but carried along as the region itself moves, conventional relativistic effects such as time dilation do not apply in the way they would in the case of a ship moving at high velocity through flat spacetime. Also, this method of travel does not actually involve moving faster than light in a local sense, since a light beam within the bubble would still always move faster than the ship; it is only "faster than light" in the sense that, thanks to the contraction of the space in front of it, the ship could reach its destination faster than a light beam restricted to travelling outside the warp bubble. Thus, the Alcubierre drive does not contradict the conventional claim that relativity forbids a slower-than-light object to accelerate to faster-than-light speeds.
Perhaps the most amazing part of the story is its inspiration. According to Cochrane, it came from an all-night TV fest with graduate students at the JPL. "I was sitting around with some of the grad students, and we were cracking open some brewskis and watching Star Trek," Cochrane said. "On the show, they started talking about matter-antimatter reactions, and one of my PhD candidates, Monty Scott, says 'you know, I think I know how to do that.'
"By the time we had finished a couple more episodes of Trek and a couple more six packs, we had the basic design mapped out, and then we constructed a model using beer bottles." Cochrane said. "I have to give credit to my grad students Jimmy Kirk and Pauly Chekov for the model, and, of course, Dr. Lenny McCoy for the lab work, but you know, that Scotty is a miracle worker!"