You’ve probably heard by now about NASA’s warp drive. While working on an experimental propulsion system called EmDrive, they witnessed what basically amounts to a warp signature. Laser beams arrived at their destination sooner than they should have. How does light travel faster than the speed of light? It must be warp! But all the headlines on warp drive are missing a very important point.
I’ve been a sci-fi fan ever since a friend of the family loaned me a copy of DUNE in high school. From the spice-induced mental manipulation of space-time of DUNE’s guild navigators, I went on to Asimov and Clark. Of course, I was a fan of Star Trek and Star Wars. Later I discovered and fell in love with Ian Banks’s Culture series. So any news of work towards a workable warp engine is Very Cool.
But past the headline, the news is a bit more mundane. The experiments showed laser beams traveling faster than the speed of light, yes. But a few photons is a lot different than an interstellar craft. To actually have matter inside of a warp bubble, a source of negative energy seems to be required.
But the point of this article isn’t to dismiss new and exciting research. Actually, it’s the opposite. What all the news and reporting on NASA’s accidental warp drive covers up something equally cool.
What is EmDrive?
The experiment that NASA was working on was on a new propulsion system developed by British aerospace engineer, Robert Shawyer, based on old Soviet research. The “Em” stands for electro-magnetic. Instead of a rocket shooting propellant out of one end to push it forward, the EmDrive produces microwaves from electricity and requires no reaction mass.
There have been a few experiments conducted in the past, but critics have claimed that those results were caused by thermal convection in the atmosphere and not by the engine itself. A glancing look seems like the EmDrive violates the laws of physics, namely Newton’s third law. But according to Shawyer, the conservation of momentum is conserved since the microwaves push against the chamber and it moves in the opposite direction.
Since the claim in the past that EmDrive’s movement was caused by atmospheric effects and not self-propulsion, NASA decided to test it in vacuum chamber. It worked. According to NASA:
Nasa has successfully tested their EmDrive in a hard vacuum – the first time any organisation has reported such a successful test. To this end, Nasa Eagleworks has now nullified the prevailing hypothesis that thrust measurements were due to thermal convection.
So far, the effect has been modest. There were able to achieve just 43 grams of thrust. A far cry from the 1.5 million pounds of thrust of the Saturn V rocket.
Why is this exciting?
Most of the interest in this news has been about the warp drive. But any fan of Star Trek will remember that there are many other types of propulsion in that universe. In between the reactionary mass positioning thrusters that are similar to what is available today, and the warp engines is the impulse drive. According to the Star Trek: The Next Generation: Technical Manual, the impulse drive is a powered by a magnetic coil.
So NASA isn’t working on a warp drive. They are working on an impulse drive. Warp drive is exciting, but so far there is no proof that we can send matter in a warp bubble without materials that may not even be possible. But they have constructed a working prototype of an impulse drive.
NASA expects to be able to achieve a little less than a tenth of a pound of thrust per kilowatt of electricity. According to Next Big Future, A 300 kilowatt power source could take a ship to Mars in a year. A larger 2 megawatt nuclear reactor could take a ship to Saturn and the setting of Once Upon a Saturn Moon in just 9 months. This is close to what I wrote, where an ion drive system got there in 7 months using a level of thrust similar to the gravity on Titan.
EmDrive and artificial gravity
That brings up a good point. One of the problems with life in space is zero gravity. 50 plus years of research has shown us that living in zero g is bad for the body. A significant portion of an astronaut’s day on the ISS is simply exercising to maintain bone and muscle mass.
On interplanetary trips using current reactionary mass rockets, your choices are to simply wait around while Newton’s first law coasts you along for the majority of the trip, or take an unimaginable about of rocket fuel to keep you under constant thrust to generate an artificial gravity. There are also some designs for ships that rotate to generate centripetal acceleration (better, if inaccurately, known as centrifugal force) to keep astronauts butts pointing towards the floor.
Ion drives, discussed in Star Trek and being used for real in the probe Deep Space 1, are one answer to this and used in my book. But you still need a reaction mass. To go farther or faster, you need more reaction mass, and you have to figure out a way of getting it off the ground. Current ion thrusters don’t generate enough force to lift themselves off the ground in Earth gravity.
EmDrive gets around that. A single heavy lift rocket can get all the equipment needed for a round trip to Saturn into space. The Mars trip could even use solar panels to power the EmDrive while the astronauts sit comfortably under low-gravity acceleration.
Forget about warp drive. NASA is much closer to getting an impulse drive off the ground and usable for interplanetary flights in the coming decades.
Are you excited about the possibilities of EmDrive? What do you think it can mean for science fiction?