[pfdietz]

Spinoffs have a long and sorry history in NASA advocacy. The problem is that advocates went from "NASA had some minor role in development of technology X" to "NASA is entirely responsible for technology X". One sees this over and over again, to the point of the claims being outright lies. "NASA gave us integrated circuits" is a great example.

Claims that space spending had a 8:1 (or 24:1, or whatever) payback via spinoffs have typically just assumed the spending has the same macroeconomic payoff of private R&D spending, which demonstrates absolutely nothing.

Without that contribution inflation, one has to somehow show that a particular technology would not exist without the putative spinoff contribution. And that's really difficult to do in most cases. Here, the military has had an interest in high power millimeter wave sources for a variety of reasons.

The argument remains, also, that if spinoffs are an inherent part of research, then it doesn't matter what the research is on, and so you get the highest payoff by funding research that makes sense via direct benefits, as the spinoffs come regardless. You'd need to argue that fusion is somehow better at producing spinoffs than other research. I find that likely; I suspect small scale research is more likely to provide spinoffs, as desktop technologies seem likely to have more applications.

[jatone]

your attempting to dismiss the reality of empirically proven occurrences with hand waving. I have no interest in engaging in such a pointless discussion. NASA, the manhattan project, and other endeavors ALL generated giant economic returns from their outputs.

you can hand wave 'possible alternative realities' all you want but the fact is they triggered those economic returns. spacex would be another (recent) example of a primarily NASA funded endeavor that will generate massive returns in the future and would not exist without said funding.

anyways good luck.

[pfdietz]

The handwaving is on your side. How could it be otherwise? To demonstrate a spinoff effect, you have to show that the technology would not have been developed otherwise. But such contrafactual history is just about impossible to prove. And in technology, it's almost always the case that technologies come about because it's time for them to come about (it's "steam engine time"), not because of one irreplaceable inventor or group.

> the fact is they triggered those economic returns.

Your blind faith in this dogma is touching, but it isn't supported by real evidence. For example, if you examine what actually happened, the NASA role in developing integrated circuits was rather minor.

[pfdietz]

s/likely/unlikely/