Not true! Large VASIMR engines would give considerable thrust at excellent specific impulses. If leveraged properly, it would be the kind of space travel that we all want - fast and easy.
What's not true - that it is hyped beyond all sensible proportion? I am afraid that is very much the case. Haven't we been over this in a few other threads? I think I even posted a few nice video where people succinctly debunk the "fast and easy" myth. Basically, unless you have a magical power source with huge energy outputs per kilogram of mass, VASIMR ends up being comparable to other electric propulsion systems. It has a few nice features (like the ability to shift gears, trading thrust for ISp and vice versa), but it is limited by the same problems we have with other EPS.
Chemical rockets are something we should move away from, especially for deep-space travel. The idea has always been to find the right "fuel," but unfortunately we've dug out the mine on that one. Electrical propulsion is the future.
I am not arguing for sticking to chemical propulsion (however, for launches from Earth, it will remain the only viable alternative for a looooong time to come, and we both know that getting stuff from the surface to LEO is the single most difficult part of any endeavour in space).
Personally, I see nuclear-thermal as the way to go in the inner solar system. IF (big letters IF) a proper power source is developed for use in deep space to power ion/plasma drives, then EPS can be used for travels there. It's just that if we ever get such a source of power, most likely a fusion reactor of some sort, it will probably easier to go straight for fusion drives (either of the "leaky" magnetic bottle type, or inertial confinement fusion) - that will remove the need to have a separate energy source and propulsion systems, which wreaks havoc to mass ratios.
Even "just" 2 or 3 Saturn-V class launchers is something on a scale we haven't really approached yet. What's more, it's something you'd have to set up anew every time you wanted to hop something over there. The problem isn't getting to Mars; we could go there now. It's getting to Mars twice, as I said. Ideal Mars mission profiles include measures for sustaining the travel bridge between the planets, rather than tying the expeditions together by separate, full-fledged start-from-scratch launches.
I think Zubrin pretty much solved that problem a long time ago (despite his latter craziness
). It's just a matter of how much risk are you willing to accept in the early flights. Case in point: aerocapture. Using it saves you a lot of propellant, but mission designers usually avoid it like plague. Another one - ISRU fuel production, again, huge mass savings, largely ignored by NASA mission designers because it is deemed to be too much of a risk.
edit: Hell, a
Falcon Heavy could do it. I just consider it a lack of the imagination to start on Earth when much more efficient capabilities exist if we were only willing to invest (and I don't just mean VASIMR).
Explain how will VASIMR make a *PILOTED* Mars mission easier. You may only use realistic present-day or near-term technologies to make your point.
Speaking of hype.
That's not hype. It's a very rich and deep book. I remember when I first read it, I could almost imagine myself being on Mars with the characters. Not many hard sci-fi books can do that.
Now I'm afraid you've lost me. What makes you think that this brand new problem with logistical nightmares of immense quality can be solved both quickly and cheaply, let alone effectively? I mean, I suppose in terms of concrete resources and discrete possibilities all of the individual technologies are there and certainly existent to allow a sustainable Mars base to exist theoretically, but bringing them together is a task of monumental proportions.
I see this kind of overestimation often, by both people within and without the field. Generally, and I don't want to lump you in with these types, by people who see a documentary on the Discovery channel about how we could be building magic space ships right now if only those incompetents at NASA would get on it! It betrays such a critical misunderstanding of the complexities at hand, both in systems engineering and integrated spacecraft design in general that I don't even really know where to start.
I guess what I mean to say is that while you aren't technically wrong, I just don't see such a program going off cheaply, quickly, and correctly. An old NASA saying is "pick any two," not because of incompetence per se, but because the technical iniquities of the task don't exactly make it so easily approachable from a top-down procedural development perspective.
I tend to avoid American space documentaries on TV, because they make me want to yell at the screen and throw heavy objects at it because of the amount of disinformation and stupid simplifications in them.
My point here is that if we are building a *colony*, not a research base, a real honest to gods colony, then it will be designed to be extremely self-sufficient from the very beginning. It will likely build on the experience accumulated during previous missions.
I can be far more sceptical than you are when I see pie in the sky space projects some people propose (like VASIMR for manned missions to Mars
), but I am not *pessimistic* about the problem-solving abilities of the people who will make this happen. If a Mars project were to cost trillions of dollars, IT WILL NEVER HAPPEN. Period. Which is why it won't cost that much. Where there is ambition, better solutions will be found.
)
I am fine with that. Maybe when the Martians send out the first interstellar expeditions to show the Earthlings how stuff's done, we might find some pride in the knowledge it was we who made the Martians.
? That's interesting. Is that how the Crown thinks
