> Having TV blasted from space, GPS to know to turn at this intersection, and pictures of every roof on the planet is useful. None of those technologies could have happened if we didn't send people in tin cans first.

The first geopositioning satellite[1], first satellite that broadcast of a human voice from space[2], and the first photos taken from orbit[3] all predate the first human in space[4].

[1] https://en.wikipedia.org/wiki/Transit_(satellite) [2] https://en.wikipedia.org/wiki/SCORE_(satellite) [3] https://en.wikipedia.org/wiki/Explorer_6 [4] https://en.wikipedia.org/wiki/Vostok_1

How do you make your conclusion?

Telstar 1 started blasting TV from space in 1962.

I don't know how that required Gargarin or Shepard to be in their tin cans first.

Also, we sent up SCORE in 1958, and famously Arthur C. Clarke wrote about using satellites for telecommunications in 1945.

TIROS, the US's first weather satellite, preceded Gargarin.

KH-1, the US's first spy satellite, meant for photographic surveillance of the Soviet Union, was even earlier.

These certainly didn't require humans in tin cans first.

Lunar mining of 3He is a huge canard. It likely requires more energy to extract it from regolith than it returns from fusion (10 ppb is not much!)

3He can be made by DD fusion (which either produces 3He, or produces T which can be allowed to decay to 3He; neutrons from DD fusion can also be used to make tritium which can also be allowed to decay to 3He.) This is Helion's plan, with the system operated in a mode that suppresses DT fusion.

See https://gundam.fandom.com/wiki/Jupiter_Energy_Fleet from the late 1970s; people have been thinking about this problem for a long time. This SF TV series cheated with a new physics which allowed compact nuclear fusion reactors minus the ability to do anything with neutrons. We still don't have a good path to them for basic electrical power generation, seeing as how much we're still struggling with theoretical break even DT fusion, with the LLNL experiment per something I just read not counting the power input into the lasers.

I don't look at fictional sources for evidence about reality.

So fiction showing people were thinking about X at such and so a time not evidence people were thinking about X at such and so a time???

All the "get to the moon" or beyond SF, which per Robert Heinlein was an explicit goal of his juveniles, to teach the attitudes and what you needed to learn to to get into space, which he was later told actually worked for a number of Apollo project people was ... what??

Can't make fusion reactors that interesting and the SF series never tried except when they didn't get a chance to shut down properly and went boom (actually a very beginning plot point), but I'm glad for all the fiction creators who inspired me into a STEM career when I was young.

I believe pfdietz's point is there's no need to go to the Moon (or Jupiter?!) to extract 3He when sufficient 3He can be generated on Earth, at lower cost, and be energy positive.

Your digression seems irrelevant to that point.

We didn't use Heinlein stories as a source of evidence about reality. We didn't use thorium rockets to get to the Moon. Nor did we develop monoatomic hydrogen ("Single-H") fuel.

Similarly, we don't use Gundam stories.

Also, Project Daedalus' proposal to mine the Jupiter atmosphere for 3He for fusion predates the first Gundam episode, and is likely what influenced the series. https://en.wikipedia.org/wiki/Project_Daedalus .

If we're going to mine someplace in the solar system for 3He, I'd like to see it done on a (currently hypothetical) "Planet X", a Mars to Earth sized planet 100+ AU from the Sun. It could be cold enough out there for a bit of helium to remain bound over the life of the solar system, but it would be much easier to take off from again than, say, Uranus. And presumably with D3He fusion one could get out there with a fusion rocket.