Every once in a while, science-fiction nerds come up with an idea so awesome that science nerds decide to build it. Like the NEXT ion engine—NASA's Evolutionary Xenon Thruster—that the space agency's been perfecting for the past five years. That's not it, above. That's a motorcycle tricked out to look like the Star Trek Enterprise that seemed sweet enough to include.It was unclear in the beginning whether or not the Star Trek-inspired device would actually be a feasible alternative to the chemical thrusters that currently power our rockets. Ion drives, you see, work really well in space and use very little energy in the process. However, it takes them a long time to get up to speed. So this week, when the NEXT engine clocked its 430,000th hour, rocket scientists rejoiced, because finally, we'd figured out how to build an engine that could take us to another star system. Not that any single human could make the journey in one lifetime.This is not to say that the NEXT ion engine isn't fast. It is… eventually. The engine essentially works like fire hose, but instead of shooting water, it fires charged atoms that create thurst. Creating the ions is relatively simple. In the case of NEXT, they fill a chamber with xenon gas and then shoot electrons through the xenon to create charged particles. The positively charged ions are then pushed through a high-powered accelerator grid that shoots them out the back. If that sounds confusing, this diagram should help:It doesn't go too fast at first. Dawn, a NASA spacecraft with a previous generation of ion-powered engine, managed to go from zero to 60 miles-per-hour in just four days. (Told you it wasn't fast at first.) Over time, however, the power of the thrust compounds and the momentum of the spacecraft pushes it faster and faster until it hits a top speed of 200,000 miles per hour. That would get you to the moon in less time than it takes to watch a bad romantic comedy.There's still work to be done if we want to take the NEXT engine interstellar. Alpha Centauri, the closest star system to our sun, is a staggering 25.6 trillion miles away--4.3 light years. At top speed, the engine would get there in just over 14,600 years. Remember the basics of the story, though. NASA built an engine inspired by a 1970s television series about a alien adventures. They'll continue to improve it, but at least, now we know that the model works. Next, I want to see everything from Minority Report. Oh wait, it's already happening.Image via Wikimedia