[LINK] Waitbutwhy article on the history and future of space exploration, SpaceX and more

I was referring to the grand future presented with Mars terraforming in a ridiculously short time, and talking about terraforming the moons of Jupiter and Saturn.

As for Mars terraforming... we can't control a 200 parts per million problem in our own atmosphere with a whole civilization's resources. Mars has at LEAST a 200,000 parts per million problem, and toxic salts in the soil. And it's covered in crust that has never seen much O2 and will react with and suck it out of the air at a pretty good clip unless compensated for by massive biogenic carbon burial rates.

It is utterly beyond me that anyone could ever consider it possible to terraform Ganymede or Titan. They're not made of the kind of stuff that is even solid at human temperatures, they're so cold that according to my calculations boosting the upper ten kilometers of Titan's crust to human-compatible temperatures would take 50,000 years assuming it was pitch-black and did not radiate any heat to space which is physically impossible (its blackbody temperature would be something like 90 kelvin, you need a hell of a greenhouse...), and the sunlight on Ganymede is 4% that of here and at Titan it's 1% that of here so I don't think you could even do that in the first place. These bodies would also have atmosphere lifetimes at human temperatures of single or double digit kiloyears as well as near as I can calculate, especially around Jupiter with the crazy radiation environment.

What's going on in your first paragraph? How did we get from spaceflight to cars?

Without bothering to read these comments, my understanding is that fuel cells are bad for cars but good for spaceships. Batteries win on energy per volume, but lose on energy per mass. Also, fuel cells can store energy for a longer period of time, but that is relevant to the outer system, not for Mars.

very seriously given Tesla's demonstrated success

I don't know much about electric cars, but AFAIK the general consensus was that battery-powered EVs are largely infeasible unless there is some breakthrough in battery technology. Did Tesla achieve that or did they just use bigger and more expensive Li-ion batteries?

If I understand correctly, there isn't enough easily recoverable lithium in the world to replace but a small fraction of existing vehicles with Li-ion battery-powered EVs. If that's correct then, barring some breakthrough, Teslas will be forever expensive (and government subsidized) toys for rich people to signal wealth and environmental consciousness.

I don't get why there is so much Elon Musk fanboying in tech/libertarian circles. All the businesses the guy is involved in are heavily subsidized by the US government, and yet he gets heralded as a champion of libertarianism.

I mostly see the fanboy stuff coming from generic technophiles and millennial liberals/environmentalists.

It wouldn't surprise me too much if some libertarians are big fans, there is a lot of overlap between technophiles and libertarians for whatever reason. And I suppose moderate libertarians wouldn't oppose subsidizing corporate R&D if there are plausible positive externalities. Not all libertarians are purists.

True on both counts, although I believe the Mars Direct price-tag came from the same agency/group that priced out the 90 day report.

Design Reference Mission 3 was remarkably similar to Mars Direct, but DRM 4 and 5 have grown a bit from the minimalist approach, although they still revolve around In Situ Resource Utilization, just as Mars Direct did. DRM 5 is especially confusing, and it will be a year or two until we see DRM 6, so I actually think the 2011 edition of The Case For Mars is about the best book out there for demonstrating that it can be done. Obviously the rocket he describes was based on minimally altered space shuttle manufacturing capabilities and architecture which no longer exist, but the design principles haven't changed. Zubrin currently endorses a couple versions of Mars Direct based around SLS and/or Falcon Heavy. If you are looking for modern, the most modern Mars architecture I know of is Buzz Aldrin's current version of his Mars Cycler concept. I haven't read his new book yet, but as I understand it that's a grand architecture for a massive project, rather than a minimalist approach. I'm sure we could do it for a fraction of the cost of the Iraq war or the bank bailouts, but that's still many times larger than NASA's current budget. I haven't looked into the political viability, but I suspect that anything over a quarter of a percent of the federal budget isn't likely. I was trying to discuss how it can be done, rather than how to do it best. I'm definitely all in favor of Buzz and Elon if they can make their visions a reality.