Before you go too crazy with the rolling eyes and hooting, remember that this is Georgia Tech, not Ronco(tm).
Remember also before ramping up any dismissive "astronaut with a motorcycle hurr hurr" jokes, that NASA is also tasked with improving civil aviation design, powerplant design, and investigating improvements in airframe and avionics - not just sending gold plated records past Jupiter.
This is significant, as they are asserting in plain language that they're getting most of the fuel burned, therefore more energy out of the same amount of fuel. I'm interested.
I've learned that there are two kinds of people who have a problem with reality: extreme idealists and knee-jerk cynics.