If SpaceX can provide a lower cost launch option for NASA in the future, such as an expendable Falcon Heavy in the near future, or a reusable HLV in the distant future, that will be all the better.
In either case, NASA comes out a winner. The only thing that NASA really needs is a realistic, consistent exploration roadmap that is not the pawn of political upmanship and armchair generals.

Five years ago SpaceX was a company with very little to show for itself other than lots of wild promises. Their initial attempts at reusability were embarrassing failures

However, that is no longer the case. They have matured rapidly and are becoming a credible, significant provider of launch services. The rest of the industry has taken notice and has begun to imitate them, down to ULA’s efforts to build suspense by refusing to reveal any details of it’s NGLS until an April announcement.

Time will tell, but bickering about SLS vs SpaceX is probably not the most productive use of our energies.

Since you have asked specifically about solar thermal production of lunar glasses, I provide you with this link to an article by yours truly:

http://www.portaltotheuniverse.org/blogs/posts/view/357925/

Regards,
G. W. (Glenn) Smith

P.S. Yes, I am apparently one of two Glenn Smith’s involved with this blog — and I humbly yield place of precedence to the other, O. Glenn Smith, since he is Dr. Spudis’ collaborator!

Manufacturing things like solar panels and refining and fabricating metal alloy components takes human technicians- hundreds of them. No way around it. All this 3-D printing talk is fine if you have high quality stock- but creating that stock and making larger items takes a factory. The best first project in my view that can be undertaken is in orbit using robot landers to harvest and bring water up to wet workshops.

I am a follower of Gerard K. O’Neill and as such I believe the Moon is the first place to go and exploiting lunar resources to power civilization on planet Earth- and eventually acquire new lebensraum in space- is the prize.

The two central concepts of O’Neill’s vision were Solar Power Satellites built with lunar resources and the conclusion there are no bodies in the solar system suitable for colonization leaving artificial hollow moons constructed from lunar resources as the answer.

These concepts are completely contrary to the popular culture hype spread by NewSpace advocates over the last several years. A vast state-run public works project using super-heavy lift vehicles to return to the Moon is the NewSpace nightmare. So….I have to speak out when words like “cheapest” and dead end goals like LEO space stations and missions to Mars are discussed.

I want to explore Titan and the subsurface oceans of the gas giant moons as much as the next space advocate but first things first. And Mars……not even a good destination.

Mars is a gimmick; mistakenly popularized as “just close enough” to get to on the cheap.
There is no cheap.

If a variety of metals and ceramics can be extracted from regolith then I would think that you could manufacture >90% of the robot (and support infrastructure) mass (structures, wheels, electric motors…), just importing electronic components such as computers, communications, and photovoltaics.

Speaking as a non-expert, I would think that if you wanted to expand a facility that generates electric power and manufactures robots, you could just stay in one place and use the local regolith as the feed-stock.

Also, I am wondering what would be the best way to expand electric power output. Would it be best to make simple reflective solar concentrators and static thermoelectric power generators, or try to manufacture some type of photovoltaics.

This is a technology that could be pioneered and continuously refined here before implementation on the lunar surface.

Dr. Spudis’s editorial produced a lengthy list of technology developments required to make long term habitation modules possible. The Nautilus-X and other design concepts would all benefit from these developments, but none of them simply by their existence helps to produce those advancements. Thus they do nothing to change the editorials cost estimates.

The Falcon Heavy discussion has pretty much been had, except to note that a pro Falcon Heavy supporter above (Nelson Bridwell, March 13, 2015 at 8:22 pm) now says he expects the first launch in 2016. That is in keeping with the SpaceX “tradition” that the first Falcon Heavy launch is (like tomorrow in the old song – “always a day away”) always a year away. If it ever does launch look for (in another SpaceX “tradition) its cost to triple.

Scale is the primary obstacle in Nuclear Pulse Propulsion. Building pulse units small enough and getting a plate or sail device large enough to be efficient outside the magnetosphere are the problems to be solved. Fortunately, large sums have gone into fusion weapon research devoted to making H-bombs as small as possible.

The two options for a pulse propulsion “engine” are a giant parachute-like sail or a big dumb plate. The parachute, or “Medusa” concept, would require very small bombs and would probably not be very durable. It might serve as an interim but the multi-thousand ton monolithic metal plate is where extremely high Isp numbers in the tens of thousands are found because larger bombs can be used. I like to think of them as flying saucers made real.

Fabricating such massive plates on the Moon would open up the solar system to human exploration. Such extremely high velocities would be possible that round trip journeys to the gas giants might take only a few years. There is certainly no shortage of plutonium. Welcome to the 21st century.

There’s a sucker born every minute.