Here's the kicker: it's also more powerful. NASA says the safer fuel offers about 50 percent better performance, so you can either go farther on the same fuel or reduce the amount of fuel you need to carry on a given mission. That could be particularly useful for missions to the Moon and Mars, where cargo space will be at a premium.

You won't have to wait long to see how well the fuel works. GPIM is poised to launch in late June aboard the same Falcon Heavy rocket carrying LightSail 2. If it succeeds, it could make spaceflight safer as a whole, not to mention far more efficient.