[RightWhale]

A linear accelerator of any sort would seem to me to be essential. A "gun" of some type would, in fact, work,

Rail guns have won the race for preferred launcher from the moon. Once an appropriate critical mass of our act has been placed in space the rate of space development should accelerate so rapidly that mid-level government space planners would want to throw their white papers into the back of the third drawer down of the file cabinet and finish the career mastering Civilization III.

[tim politicus]

Yes I agree, if the process can only be "jump-started" it will eventually grow exponentially of its own momentum. The problem is that darn HUGE startup. The first investrors in both the Panama canal and English colonies in North America lost everything, I think. But once there are accelerators like that in LEO or the moon or in-between...

What really attracted my attention on this thread is a lot of what boris and others were saying about the astronomically (ha ha) better efficiency of chemical over 'electromagnetic propulsion. That got me thinking about railguns as well. Darn problem is the limited acceleration time, even with a vast system.

Are railguns or guns of any significant use at all beyond about a lunar orbit?

To me all what this shows is that it is going to take _a lot_ of work and time and organization and inspiration to get where we need to go. I'd think we need some cultural and social changes before we could pull much of this off.