At Standard Temperature and Pressure...
...how much volume does a ton of He-3 take up? And how much lunar regolith do you have to process to extract it?
Its starting to look like all the low-hanging fruit has been picked clean.
From now on, it looks like we're going to have to work for our supper.
Daedalus requires 50,000 tons of fuel.
Still, the vision of fleets of nuclear powered blimps cruising the Jovian clouds to suck out the rare isotope, all to power just one interstellar probe, does have some sort of grandeur to it.
Some things are possible, but unlikely. It takes a great deal of energy to push something up to a few percent of the speed of light.