Let’s not talk about fusion-based propulsion before we have a fusion-based reactor. The lack of a successful fusion reactor is probably the biggest engineering disappointment of the Twentieth century. Let’s talk thorium based fission reactors instead.

Is there an economic reason to use a libration point in space travel, other than the relative ease of maintaining a stable orbit there? What are the savings in time and fuel? I suppose the slingshot effect of navigating an orbit around earth or the moon would be benefical for an expedition launch.

My personal preference is to plant a rock, a very massive rock, in geosynchronous orbit as the basis for a exploratory colony. Over time we could lower a beanstalk (space elevator) until suborbital craft could navigate to a dock in low orbit, before climbing the beanstalk on electric power (solar cell collection roughly 12 hours a day).

I’m betting it’s 1,000 times greater than costs to the middle of the Sahara desert. Let NASA prove it can establish a hermetically sealed solar powered permanently manned space colony in the middle of the Sahara Desert before it starts wasting endless money on a L-2 or L-3 space colony. The technical and economic challenges of the orbiting colony would be many times greater than the Sahara colony, yet the challenges of the Sahara still seem beyond NASA’s reach. Most of the money invested in manned space projects before the development of strong natural language AI will just be wasted money. I’d support NASA funding of AI robotic systems and a sealed “space colony” in the Sahara. Give NASA $200-million to prove their concept space colony concept in the Sahara, with the understanding that the orbiting space version would likely cost one thousand times as much: $200-billion.

A joint French/Russian/Chinese heavy lift project to place millions of pounds of space junk at Earth/Moon Lagrangian points would be fine by me. Let the French/Russian/Chinese cartel enjoy all the Helium 3 they can ship back to Earth. I figure they would likely give up before they waste $200-billion, never collect the first nanogram of helium 3, and they would lag far behind US development of hermetic life support systems and strong AI. I want US space funds dedicated to Earth-based AI and hermetic life support systems. That deliberate walk-before-you-run program will put the US far ahead in any race to exploit space, and humanity in general will be the better for it.