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Comment Re: Great idea... But there is a problem... (Score 1) 224

I'm with a group called Venus Labs; we'll have our first book out later this year. :) Materials compatibility is a big topic therein. Thankfully, there are a lot of polymers that have good resistance to Venus's environmental conditions (particularly fluoropolymers, although minimizing coating fluorine content is important for ISRU because hydrogen fluoride is a lot less common than hydrogen chloride and sulfuric acid - so for example PCTFE or PVF would be preferable to, for an example, FEP). The sulfuric acid mist isn't actually very concentrated from a particle density perspective - visibility is a couple kilometers. The mist is a couple to several dozen grams per cubic meter, depending on the altitude, latitude, time, etc (by comparison, OSHA allows people to breathe up to 1 mg/m for an 8-hour work shift). But it is concentrated from a molar perspective - on Earth, H2SO4 mists self-dilute with atmospheric water vapour.

Comment Re: Great idea... But there is a problem... (Score 2) 224

"That book"?

Why Venus? Venus has the most Earthlike environment in the solar system outside Earth. High latitudes in the middle cloud layer have Earthlike temperatures, pressures, gravity, sufficient radiation shielding, ample light, and diverse resources already gas phase and only needing to be run through a scrubber to give you feedstocks (even iron, in the form of iron chlorides - estimated at about 1% of the mass of the sulfuric acid - which, by the way, thermally decomposes in the presence of a catalyst to release water and oxygen). Concerning orbital mechanics, Venus ascent stages are of course harder than Mars, but apart from that, it's in a much more favorable spot concerning orbital mechanics, with a much greater Oberth effect and much more frequent launch windows; it can be easier to get payloads to Mars from Venus than from Earth (and can even get gravity assists from Earth). Beyond the abundant solar power, there's also abundant wind power. Normal Earth air is a lifting gas. Unlike a Mars habitat which is a cramped pressure vessel, a Venus habitat is an expansive, open, bright area, full of plants and life. If you don't like someone, go hang your room elsewhere in the envelope, potentially even hundreds of meters away. Bored? Jump into the safety netting; the scale indoors is so big you can basically do indoor skydiving.

As for learning, Venus has vastly more unknown than Mars. Venus is our twin, and the question as to why it ended up the way it did and Earth didn't is one of the great questions in planetary geology. Venus used to have oceans like Earth. Yet today its surface has become this alien place, a veritable natural refinery that bakes and erodes minerals out of the surface and precipitates them out in the clouds. The whole planetary surface, or nearly so, resurfaced itself about 500 million years ago. We have no idea why. Can Earthlike planets just up and do this? If so that's a very disturbing concept. it has the longest river in the solar system - we have no clue what carved it. The best theories are really weird, like natrocarbonatites - super-rare low-temperature lavas that look like oil, flow like water, and glow crimson at night. It has lightning, but we can't seem to find it. It seems to be the second most volcanically active place in the solar system (after Io) but we've never positively confirmed an eruption. There's a huge amount that our planetary models just can't explain. Why doesn't it have an intrinsic magnetic field? Even with its slow rotation speed, dynamo theory says it should; it doesn't. Where's its mercury? Chemical models say that there should be 3 1/2 orders of more in the clouds than the upper detection limits of the probes thusfar constrained it to. What are the strange radar reflective frosts / snows in the highlands? Pyrite? Galena? Tellurium? There seems to be more than one type, too. I could go on for pages and pages here. And there's vastly more reason to have humans present for exploration on Venus, because given the surface conditions, latency for controlling robotic probes is very important - unlike Mars, where communications "downtime" for rovers just gives them more time to charge in the weak sun. And you don't have to worry about degeneration due to low gravity like you do on Mars.

The surface, while hostile, is absolutely accessible. The Soviets had a lot better success probing the surface of Venus than they had Mars. The basic design is very simple: metal shell. insulation, and a material that absorbs heat through a phase change; it can easily buy you a couple hours. Tech developed by the Soviets in the 1960s. It's been determined that you could actually shoot a hollow titanium sphere at Venus, without any kind of heat shield or parachute, and it'd reach the surface intact; that nice "fluffy" atmosphere goes a long way. On Mars you have to have controlled propulsive landings onto rough terrain with little to slow you down - something that continues to randomly kill landers. The surface air on Venus is dense enough to allow you to dredge minerals off the surface.. You can get off the surface, too, with phase change or bellows balloons. The surface is even accessible for humans, and not just in "submersible"-style vehicles - through atmospheric diving suits like are used for deep sea human diving. NASA was developing such "hard suits" for the Apollo program and a bit after - the AX series. They went with soft suits because they're lighter, but hard suits have better mobility. And more to the point, on Venus with such a suit and a bellows balloon, a person could literally fly - floating up, and gliding down with little wings in controlled flight at up to a couple dozen meters per second.

Comment Re: Great idea... But there is a problem... (Score 1) 224

What is the cost of launching a Mars vehicle directly from Earth?

$7k/kg by Falcon Heavy pricing. Would you rather a different launch system?

Insanely high

Not really. But the problem is your "lowering prices" standards involves having to send things into to an entirely different gravity well (consumables), and landed propulsively, so that other different things can then be launched from said gravity well.

And it has diminishing returns

Your proposal, absolutely.

From Earth, there are no diminishing returns whatsoever. Just the opposite - the more you launch, the cheaper it gets per kg.

There is no practical way to launch a large enough manned vehicle for Mars

One: completely and utterly false. There are a huge number of different proposals for this, all of them technologically feasible.

Two: your counterproposal involves doing the same for the moon, and then doing constant resupply so that they can build things that require an entire industrial base there. It's an absurdity.

Let's take a look at the Falcon Heavy heavy lift vehicle [wikipedia.org] which is one of the heaviest available right now. The payload to Mars is about 13,000 kg. That is about the weight of 1 ISS module.

And?

No, seriously, and? Just ignoring that you can launch to LEO, including transfer stages, and this you actually can launch over 50 tonne segments, is your notion that humans can't build things in space? If not, walk outside tonight when the ISS is due to pass overhead, and look up.

The cost per launch is $90m. Want five launches to build it? Ten? Fifty? You're still a fraction of the cost of establishing the sort of industrial infrastructure needed on the moon to support rocket launches, which in turn is still going to cost more than from the Earth due to the cost of said infrastructure's imports.

Have you ever thought why no NASA missions to outer space has been refueld?

You mean like the ISS?

The ISS station gets refueled all the time but not probes. Why is that?

Because it's cheaper to just build things on Earth and launch them, exactly the point I've been trying to get you to understand this whole time. Doing things in space increases the cost, and the further you are from Earth, the greater that cost is. Work in LEO is expensive because everything requires consumables that must be launched (humans in particular). Work on the moon is vastly moreso because it requires vastly more delta-V to get there. You're wanting to do the vast majority of the work at a place where costs make LEO look like a bargain. Work that can't even be done without developing a whole industrial base to begin with.

By your logic, NASA has no plans for Mars either.

Incorrect, and an absurd statement to make. The "Journey To Mars" program is the core of NASA's focus. (If it wasn't, nobody would ever put MOXIE on Mars 2020. ;) )

This is getting absurd. If anyone else wants to talk to this person (who actually goes by the name "UnknowingFool" - almost starting to wonder if this is trolling), go ahead - I'm out.

Comment Re: Great idea... But there is a problem... (Score 1) 224

Nowhere did I say that NASA needs to rebuild and entire installation; however, in terms of fuel cost it is much easier to launch from the Earth to the moon then refuel at the moon

Implicit in saying that is the premise that the moon has an industrial base, because you don't make fuel and launch rockets without an industrial base. And an industrial base means dependency chains. And even importing a very small fraction of the amount from Earth to fill gaps in their dependency chains that they launch from the surface would easily price them out of the market. Never mind the absurd capital costs you have to amortize.

Current NASA plans have the moon as a refueling point

NASA has no plans for a lunar refueling point. It is not part of any actively-being-worked-towards timeline. They've posited the concept before, but they've posited a million fanciful things.

Comment Re: Who cares? (Score 1) 224

So all the water on the moon that could be used as fuel for Mars missions has no value?

I'd love to see your proposal for launching water from the moon to Mars for less than $7k per kilogram. Include all allocation of labour, all feedstocks production, and all consumables, including system maintenance.

The reason we launch from the Earth is Earth is where our industrial production infrastructure is. And even if you have to import just a couple percent to the Moon of the mass that you could launch from the Moon in payload (aka a highly evolved industrial base), you've blown your budget. Just ignoring that the needs of Mars most definitely aren't water. It's habitats, vehicles, and industrial / manufacturing hardware. Have fun trying to produce that sort of stuff on the moon.

Comment Re:How much to re-create Apollo? (Score 1) 224

As you note, the tooling for Apollo doesn't exist. The suppliers don't exist. Some parts of the design don't exist any more, and that which does is just on paper. Everything would have to be started over in terms of modern CAD diagrams, full testing, etc. It would be more expensive to recreate Apollo than to make a new system with better performance. Today we have better alloys, better performance designs, more knowledge. And we do have infrastructure and suppliers that exist today, so it makes much more sense to make use of their capabilities than to recreate that which existed in the 1960s.

Your post seems premised on the notion that finding a way to make a big rocket is hard. It's not. There is no shortage of ways to come up with arrangements to reach the moon. The hard part is the low level engineering and testing, both at the component level and integration level. And we don't get that by going with Apollo. We actually lose in that regard, versus going with more modern systems.

Comment Re:We are finally getting over (Score 5, Insightful) 224

Could you describe to me what is the "Obama space malaise"?

Obama didn't want SLS. It was congress that mandated it. And I'm in agreement: SLS is a giant unfunded mandate. "Let's build a rocket that will be way too expensive to make significant use out of, and which we won't have the budget to use often enough to make reliable or at all cheaper".

You don't make mandates that you're not going to fund. So much of congressional NASA mandates have been make-work programs, trying to justify keeping Apollo and Shuttle-era facilities open - the cost of keeping those facilities open inherently making anything that they do very expensive. It's no mystery that they need to cut back and streamline their operations to be competitive. But they're not allowed to.

Honestly, I'd like to see NASA become in many ways NACA again. An science agency with a focus on advanced research projects that help improve aerospace technology and understanding in ways that others can make use of. Now, exploration is in many ways part of that. But "NASA as a rocket manufacturer" strikes me as akin to the government running a passenger jet manufacturer or the like. I see the current situation as totally backwards - why should NASA be redoing the tech of the 1960s, while private companies are the ones doing innovations like first stages that return to pad for reuse? It should be NASA developing new technology and the private sector exploiting it.

And this was the approach that the Obama administration was pushing for, with the very successful COTS program. There are many things I have to fault it for, but this is not one. I mean, seriously, how weird is it that Republicans are pushing for things to be run by a big government agency that does everything internal, and Democrats pushing for greater privatization and outsourcing? ;)

Comment Re: Great idea... But there is a problem... (Score 4, Interesting) 224

While they are different ways to get there, one path is to first establish a moon base and launch from there instead of Earth orbit.

Launch what, exactly, from the Moon?

I think you're confusing "a moon base" with "a full industrial infrastructure capable of producing complex objects". Even the concept that it would be cheaper to launch unrefined raw regolith from the moon cheaper than we can launch equivalent mass payloads from Earth anytime even remotely soon is absurd.

Earth is where industry is. The fact that we're a deep gravity well increases costs, but that difference is nothing compared to the difference in industrial capacities on and off Earth. Every production process has feedstock and consumables dependency chains. Those have dependency chains, and those have further chains, to a massive network of ever-increasing complexity. One of the worst dependencies is humans, which in turn spawn massive dependency chains.

Now, ultimately you can meet these things to the degree that the few things you have to import to sustain local industrial activity (at incredible cost) do not price the cost of local rocket launches out of the market., but if you think that's going to happen any time in the next few decades, you're deluding yourself. The serious proposals for going to the moon before Mars are for the moon to function as a testbed for habitats and systems designed for Mars.

Anyway, I'm personally much more for the habitation of Venus than Mars, but that is neither here nor there :)

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