Space Provides the Resources for Its Exploration

At the risk of speaking about something from memory, off the top of my
head, and saying something that is UTTERLY NOT NEW, I'm going to say
it anyway! I read an article in the Journal of the British
Interplanetary Society several years ago that made me think of this.
The article estimated the cost of getting things into Earth orbit
would never drop below a certain amount (I don't remember the figure).
It recommended using material that could be acquired in space, such as
on the Moon, for building spacecraft. But its outlook as to energy for
spacecraft was rather dark and, as I recall, was based on using Earth-
based energy sources, including nuclear.

Well, there's nothing new about in-situ resource utilization as a
concept for space exploration. But since this article recommended
space as a source of MATERIAL for building spacecraft, habitats, etc.,
but seemingly ignored something obvious, I thought I'd fill in the
obvious missing blank, here. This is probably not a new idea to any
reader of this, but, anyway: If we can use material in space for space
exploration, then we certainly should be able to use ENERGY in space
for space exploration.

We have all heard about Helium-3 on the Moon, solar sails, etc. To me,
one of the most promising ideas (and nothing new in concept, either)
is converting the Sun's energy to antimatter. There ain't no better
source of energy in our solar system than the Sun! :-) Like another
post of mine about the Greeks and steam power, I say that if one is
casting about for a great, abundant source of energy....well, I can
think of a good source of energy in the solar system!

So this is to counter that article's implication that energy is the
limiting problem. I say, if using Earth's energy is even a problem for
getting off the planet, then someday, maybe our spacecraft will fuel
themselves up at the Sun, then come get us!