Since I'm not calling for lunar bases on the equator, this remains pointless.
The ice at the poles remains a valuable resource for potential polar bases.
There, now we've dealt with that.
Maybe I am. Maybe there is something of scientific or technological value elsewhere.
That said, I agree. The poles are likely the most interesting single location on the Moon.
With the launch and development expenses, Apollo took about $10 billion a launch.
Apollo was massively expensive. Saturn was a massively expensive vehicle, modern vehicles are not that expensive.
For mainstream Mars architectures, we'd have 4 or 5 HLV launches each launch window. I've seen you cite Grant Bonin's architecture. But this has it's own problems. And I see no evidence any of the major players are considering it.
Oh really. What are these problems, might I ask? :dry:
Of course nobody is considering it, everyone is caught up in the HLV pork frenzy. Nobody is even seriously considering a proper Mars architecture at this point, certainly not a viable or sustainable one.
I currently cannot see what, if any, plans there are for a human landing on Mars with SLS and Orion. If I understand correctly, the ultimate goal seems to be a mission to Mars
orbit, a considerably less challenging goal than a trip to the Martian surface. It is like castrated exploration.
Also an MTV must keep passengers alive for 6 to 8 months. Without regular supply and maintenance trips from earth. In a radiation environment far harsher than I.S.S. In many ways we're talking about a space hab more ambitious than I.S.S. I.S.S. cost $100 billion. And we're talking about making and lofting an MTV each 2.14 years.
No, you don't understand the relationship of what an MTV is and what the ISS is. The ISS is a full-out orbital lab, it has an absolutely huge pressurised environment and an absolutely huge power source.
The MTV is a vehicle that can get a few people to Mars, and then back from Mars. The actual, human, habitable part of it is far less extensive than the ISS, and thus cannot be compared to the entire ISS in cost.
The ISS also had launch delays and was brought up by an expensive vehicle (STS).
And while the BEO radiation environment must not be underestimated, I fear you don't try to understand the direct impact on engineering that it has. It isn't that simple in reality, but you could go as far as to just equate radiation shielding with...
blocks of plastic.
Same goes for the ERV. Unless you use a semi-direct approach that uses the same vehicle for the MTV and ERV. In which case the vehicle you're throwing away each years is even more ambitious.
May be better if they aren't the same vehicle. Hab is lighter if it doesn't need to aerobrake and land on Mars, ERV is lighter if it doesn't have hab stuff within it... you get various knock-on effects, etc.
Given propellant deliveries of comparable mass, a 14 km/s propellant tanker is much bigger than a tanker that only needs to achieve 5 km/s.
Haven't you heard about staging? It is a really interesting concept, I believe it was developed around the time of the turn of the last century, by a guy by the name of Tsiolkovsky...
Also, your first stage does not need to be kerolox, as the Delta IV demonstrates. With RS-68A engines it ends up getting payload performance in a vaguely similar range to Atlas V Heavy. But launchers have been using kerolox (in whole or in part) for decades and it isn't really a problem, despite the lower impulse.
S-M movies are at the forefront of your mind. Therefore 8 km/s is trivial. Okay.
You fail to differentiate between propulsive braking and aerobraking. Have I explained the difference before?
I've already cited credible engineers saying re-entry is a formidable problem. The most credible counter-argument you've offered is Alan Bond's rocket which has never flown. And I believe even Alan Bond would tell you 8 km/s re-entry is a non-trivial engineering challenge.
"Formidable" is not "impossible horror engineering".
Also, I would not criticise Alan Bond and his 'paper rocket'. Mr Bond and his team are both more qualified and more knowledgeable about their concept than either of us are.
Also: I have not seen people crying about Skylon's heat shield, and saying it's impossible.
LEO propellant depots need steady throughput. Commercial space needs a market allowing a steady, high flight rate.
An architecture constrained to 2.14 launch windows offers neither.
Sure it does, I can't see any reason for it other than your insistence on the matter, and I haven't seen anyone else use similar arguments.
So I'm chiefly fixated on the asteroids, not the moon.
It would seem otherwise based on what you're saying here.
"Reduced dV" does not matter if propellant is dramatically more expensive.
Most of these enthusiastic proponents have track records. Unlike you.
Zubrin has a track record too...
Spudis is proposing a demo here. Initially lunar ISRU would mitigate transportation and life support expenses for a lunar base. After these expenses are reduced and R & D has developed working mining equipment, the next 1000 tonnes would cost less.
You have to factor the cost of this "demo" into the total cost. You have to factor the R&D cost into the total cost. Expanding on that lunar capability would cost even more.
The crater walls intercept some of the ejecta. Also the accumulating ice layers give protection other parts of the lunar surface don't enjoy. Many meteors arise when we pass through a comet's path. Both the earth's velocity vector and most the cometary debris velocity vectors lie roughly in the ecliptic plane. The normal to the polar surface is also normal to the ecliptic plane. Flux of a vector field through a surface is dot product of vectors with surface normal. So I would expect meteorite flux in the higher latitudes to be lower than the higher latitudes.
Got any source that states that impact flux is lower at the highest latitudes?
Even with ejecta and meteorite impacts, the moon is still a far better historical record than Mars. Mars' recently active geology and weather have erased many of the older events.
You display a lack of knowledge about aereology. Portions of old crust
do exist on Mars, even some of the younger crust is quite old by standards on Earth and has not been interfered with in the same way (Martian weather is not Earth weather).
Also, the record of
what is what differs between the Moon and Mars. A lot of things that occured on Mars didn't occur on the Moon.
But they did, however, occur on Earth as well. Or at least similar things occured. That makes them interesting.
Not because I insist it be so.
I.S.S. vs Mars
Delta V to LEO 9 km/s
Delta V to Mars 13 km/s
Trip time to LEO: hours
Trip time to Mars: 8 months
Launch Windows to I.S.S.: every day
Launch Windows to Mars: each 2.14 years.
Light lag to I.S.S.: less than a second
Light lag to Mars: 10 to 50 minutes
That specific physics is not everything, and you take a very simplistic view of the forces involved that make operations difficult.
Sorry, building infrastructure on Mars is a little harder than building in LEO.
Harder, yes. By how much, I really am not going to take your word for. :dry:
Earth industry is already advancing telerobotics. As easily exploited resources and ore bodies are used up, we will move to the wastelands and sea floors. When we start seriously exploiting the ocean floors, I expect telerobotics to advance even more rapidly.
So we don't have to rely on NASA's budget to improve this technology.
The movie industry is advancing the state of art for motion capture. For example Mike Myers wears motion capture sensors to operate the virtual puppet we call Shrek. Wii and Kinect have brought motion capture to computer gaming. It looks like the entertainment industry is driving motion capture improvements (which can be used to operate telerobots).
You speak of telerobotics as if they're some sort of wonder technology.
I think telerobotics are very interesting and very useful. But wonder technology does not exist in reality.
Do you actually know how much it would cost to construct a lunar telerobot? To actually have the facilities to operate it? How much it would cost to get a qualified person to operate it? It is not trivial.
And as I've already mentioned, propellant depots at various locations would make transportation much more economical.
Oh no, I'm not denying that. There are a lot of physics advantages to it. The problem is when you try to ship propellant from a wilderness location and handwave away the difficulty of actually obtaining that propellant usefully.
See
Akin's Laws of Spacecraft Design;
Law #8;
In nature, the optimum is almost always in the middle somewhere. Distrust assertions that the optimum is at an extreme point.
I believe you have written a premature obituary for space industry.
Because the Magical Space Science Fiction Dream Future hasn't occured yet, even though we've been promised it for 50 years and it
hasn't occured yet and doesn't look like it will? :dry:
