e notion of interstellar ight may not be so far fetched

Want to be cheered up as we close out the past year? Okay, how’s this? It’s starting to look like interstellar travel may be possible in a time frame that would be manageable for human beings.

No, it’s not a cure for cancer. But we know that we are bound to nd that eventually, so long as our civilization is not destroyed by war or global warming or a random asteroid strike. Until very recently, our understanding of science told us that travel even to the nearest stars will never be possible.

at may still be true, for the answers are not all in yet. But last April the U.S. National Aeronautics and Space Administration gave James Woodward and the Space Studies Institute a Phase 2 grant under the NASA Innovative Advanced Concepts program.

ey got a Phase 1 grant in 2017 to work on their proposed space drive. ey made enough progress to keep NASA happy and themselves credible, and they have now been funded to test new designs that increase the thrust produced by their Mach E ect Gravity Assist (MEGA) drive. If that scales up satisfactorily, we will one day be able to build spaceships that go to the stars.

I must admit that I really enjoyed writing that last line, for all my life I have been told that interstellar travel is only science ction. Real space flight is ruled by Russian scientist Konstantin Tsiolkovsky’s classic rocket equation of 1903, which says that a rocket can get into space by expelling enough of its mass (fuel) at high velocity, but also says that the payload and/or the speed is strictly limited.

More payload or more speed is possible, but only by burning more fuel. You must carry that fuel all the way from launch, which makes the vehicle heavier, which requires more fuel, and so on.

e “tyranny of the rocket equation” is what makes space ight so expensive, and interstellar travel by rocket impossible. For a manned spaceship to reach the nearest star (Proxima Centauri, 4.2 light years), slow down again when it gets there, and do it all within one human lifetime, it would have to burn an amount of fuel roughly equal to the total mass of the sun.

e fuel is the problem, not the distance. If you didn’t have to bring the fuel with you, sending a 400 kg. payload to Proxima Centauri and putting it in orbit around the most Earth-like planet would require a few years’ acceleration at a modest 1g, a maximum speed of 0.4c (fourtenths of light-speed, so no major relativistic e ects), and a few years’ deceleration at the far end. It would arrive in around 20 years.

So along comes Dr. James Woodward, who published his rst peerreviewed article on the Mach e ect in 1990, and Dr. Heidi Fearn, his colleague at California State University, Fullerton. ey worked on the theoretical physics of the Mach e ect, they built miniature models of a space drive that doesn’t need to burn a propellant and tested them, and gradually the space community began to take them seriously.

I’d explain the Mach e ect in greater detail, but I barely understand it myself. Suffice it to say that their MEGA drive uses electricity to produce mass uctuations within a block of metal, which in turn propels the drive forward without burning fuel. What is it pushing against? All the rest of the mass in the universe. is isn’t a sure thing. There is still controversy over whether the ‘push’ is real, or just an electrical or magnetic e ect that creates a false positive. But NASA is willing to spend money on it, and a lot of other scientists are now following up on Woodward’s and Fearn’s work.

It would open the doors to the rest of the universe for us. Exploration, colonization, unlimited resources, perhaps contact with other intelligences – all of that becomes much more possible than it would if we must remain forever confined to this one small planetary system. And, of course, it would make getting around this system a great deal easier: the moon in four hours, Mars in two to ve days, Jupiter in seven to eight days.

How’s that for (potentially) good news?