[archgoon]

> Nuclear has amazing power ratios but detonating a nuclear warhead to get moving is somewhat of a problem when you're close to earth.

It's not really a 'near earth' issue. Fallout concerns can probably be mitigated (and Freeman Dyson came up with a few ideas in that direction). Research in this direction, however, got killed as part of the various test ban treaties.

From the perspective of trying to reduce any country's desire for having a nuclear bomb program, Project Orion, and other nuclear solutions, is a no go. So even if you were to promise "We'll only start the nuclear component when we hit the moon" the proliferation concerns would still kill NASA's interest in pursuing it.

So yeah; it's not really a technical issue at it's core (though you definitely have technical issues to solve), but rather a political one (which certainly doesn't invalidate it).