>How exactly are you measuring "return" in this case?

it would have been cheaper to send the astronauts to the moon without returning them to earth

more seriously, the work that went into developing microelectronics returned a lot to the economy.

the human genome project has only just started returning its benefits

the R&D for manned moon missions didn't have much in the way of spinoffs.

Right! Even taking "return" very literally, the lunar rock samples brought back are incredibly valuable to science. And the spinoff/technological stimulus value of the program is even harder to quantify--consider that during one year, Project Apollo purchased >60% of U.S. semiconductor production. This was a critical early market for Fairchild Semiconductor, e.g. [1]

[1]:https://books.google.com/books?id=gXYItzQARVoC&pg=PA127&lpg=...

Well, you know, things like microelectronics, medical imaging, telecommunications, weather forecasting, stuff like that. Nothing important. Certainly we would have been better off if that money was spent here on Earth rather than sending it all into space.