This technology, first conceived many years ago, has now been developed to the point where it could significantly improve space travel times. It works by heating argon, a normally very unreactive gas, so that it becomes a plasma which is then focussed out of the rocket to provide propulsion. There are also other benefits in that it can make use of renewable energy, thereby lasting longer than current technology, and it can also clean and coat surfaces at a nano-level.
I find this particularly interesting because this new propulsion system would reduce the time it takes to travel in space significantly, making space exploration easier and faster. Trips to mars would currently take around 300 days, but reducing it to 39 days could allow more frequent visits and so more research can be carried out. It would also allow researchers to explore the farther regions of space, and is a step closer to making human visits to some of the outer planets in our system more viable.