NEXT is a seven-kilowatt thruster that receives electrical power from solar panels or a nuclear power source

NASA's Evolutionary Xenon Thruster (NEXT) ion engine has broken the record for hours of continuous operation.

The NEXT ion thruster has clocked 43,000 hours of continuous operation at NASA's Glenn Research Center's Electric Propulsion Laboratory, breaking the overall record. The 43,000 hours is equivalent to nearly five years of continuous operation.

NEXT is a seven-kilowatt thruster that receives electrical power from solar panels or a nuclear power source instead of burning fuel. The electricity is then used to ionize molecules of xenon and a cathode to accelerate them electrostatically. When the molecules come out of the engine, they create thrust.

For the entire 43,000 hours of continuous operation, NEXT only consumed 770 kg of xenon propellant. The engine would offer 30 million-newton-seconds of total impulse to a spacecraft.

The NEXT ion engine is meant to send spacecraft into deep space missions further and faster with more efficiency than engines that burn fuel.

Making more efficient spacecraft has been an important goal in the space industry. For instance, SpaceX, a private California-based space transport company that was the first of its kind to send a spacecraft to the International Space Station (ISS) this year, recently showed off its Grasshopper project for reusable rockets. The Grasshopper Project is a Falcon first stage with a landing gear that's capable of taking off and landing vertically. It does this by shooting into orbit, turning around, restarting the engine, heading back to the launch site, changing its direction and deploying the landing gear. The end result is a vertical landing.

A very simplified version of how the math is done:

Assuming initial speed of zero, you accelerate constantly for the first half of your trip, finally reaching a speed of say 100,000 miles per hour. You flip over and then decelerate at a constant rate until at the end of your trip you reach a speed of zero.

Simple algebra here kids. Your average speed for the whole trip is half of your maximum speed at the halfway point or 50,000 miles per hour. What do they teach in school these days?

Now, this example is not entirely accurate as there is always the acceleration of gravity from the Sun and the Planets affecting your actual direction and speed (vector). Also since we are burning fuel during this hypothetical trip, the mass we are moving is less as time goes on, so we get more acceleration from a given amount of fuel at the end of the trip than we did at the beginning.

While the thrust, and therefore acceleration, of an Ion Drive is very low, there is little/no friction in space so your speed just continues to build up because an Ion Drive is so efficient that it can burn continuously on very little fuel. Great for long trips in open space, useless for getting off planet, haven't done the math for a trip to the moon.

"What would I do? I'd shut it down and give the money back to the shareholders." -- Michael Dell, after being asked what to do with Apple Computer in 1997