That’s what fusion has always been called. The old joke is that it’s the energy source of the future, and it always will be. Back in the seventies, we used to talk about the fusion constant–forty years–as the time it would take until fusion became commercially viable. That glorious day continues to recede off into the future. Now we learn that a leading researcher in the field threw in the towel shortly before he died.

I’m not as pessimistic, but I can see how someone could get discouraged after devoting one’s life to the goal and seeing so little progress. I think that we probably will still need better materials, but I wouldn’t give up hope yet. On the other hand, I wouldn’t bet on it, either–we need to be working on a number of fronts (including space power).

[Update a few minutes later]

I’d still like to hold out hope for fusion propulsion, even if it won’t be practical for electric power generation. How much harder/easier is that problem? It’s one that hasn’t gotten as much effort, but it’s not clear whether or not if you get one, you get the other.