Today, the National Ignition Facility passed a new milestone, heating a hydrogen fuel until it emitted more energy than it absorbed, fueled by the atomic energy released in fusion. The results bring the lab one step closer to turning nuclear fusion into a viable power source — although, as scientists were quick to note, there's still a long way to go.

The process works by shining 192 beams from a powerful laser into a small pellet of hydrogen fuel, hoping to heat a small area to the extreme temperatures required for fusion. While the lab has succeeded in getting the fuel to export energy, the process overall is still a net energy loser, thanks to inefficiencies in the laser system. Still, scientists believe the results will provide an important boost for the project, and potentially spur further research into nuclear fusion as an energy source.