NERVAfan
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Posts posted by NERVAfan
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No, it hasn't. I've no idea what you're talking about.
http://www.jpl.nasa.gov/news/news.php?feature=4549
Curiosity didn't find brine, just measured conditions that would be favorable for brines to form.
The places where there's ice close to the surface are pretty close to the poles, and winter in the polar regions of Mars is not something you want to be dealing with.For solar power, definitely; but if you have nuclear power, it may not be so bad. Mars is cold, but its air is very thin, which should reduce rates of heat loss.
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"Cubical satellite"?
CubeSats have a set of standard dimensions/specs. 1U = 10x10x10 cm, <1.33 kg. And then the larger ones are built up from that (2U is 20x10x10cm, 2 1U cubes stuck together; 3U is 30x10x10 cm).
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Ions are just niche anyway -- KSP-system delta-V requirements are very low and nuclear engines are available.
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Mars-in-Venus's-orbit wouldn't be habitable due to its low gravity & lack of magnetic field - it would lose air and water (likely faster than in reality due to being closer to the Sun).
Venus in Mars's orbit... I don't think anyone really knows. Its higher gravity might mitigate the loss...
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1 person could have psychological problems and destroy the spacecraft from the inside...
Some people, maybe even most, sure. But there are people who would be just fine (especially given modern entertainment). Human psychology is pretty variable, and hermits exist.
Then we are there no megacities in the Sahara Desert?It's not analogous. The Sahara is extremely politically difficult, and there isn't a "dream" attached like Mars. (And no Elon Musk type figure pushing it.)
If Mars is colonized, it won't be for resources - shipping resources across space doesn't work anyway. But a Mars colony would attach the kind of people that would make it an innovation hotbed, IMO. And information is cheap to send between planets
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I think doing it with 1 person would be better. Less mass, but more importantly, you're IMO more likely to have violence with 2 people cooped up together than 1 person is to have deadly health problems (no one to catch an infection from, etc.)
Other than that, it's ludicrous to think that this could be done in a Dragon, or that you could develop and test a 2-year life-support module for that amount of money.I don't see why not, actually. If it was 1 person... 500 days at 5kg of supplies/day... that's only 2500kg. And water is dense. You could probably fit it all in. And there are *some* people who would be fine cooped up in a tiny space for 500 days.
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The thing is, IRL you can't make an SSTO including jet engines.
And here's the deal with all the "realism" discussions. IMHO, there are people whose idea of "realism" ends up being "mods I like", be it FAR, DRE, TAC-LS or something else. But if we want to get into realistic air breathing engines, players shouldn't be able to make an SSTO with them, period.
The thing is: should it be easy if we're discussing realism? We won't know if Skylon works until it works. And we know none attempted to make an SSTO which carried the extra weight of engines unable to work in space, nor with large wings as it's usual in KSPOn Earth, yeah, but Kerbin orbital velocity is only like Mach 7-8.
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I think some solar sail proposals could get to the outer-outer solar system within a few decades too.
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WISE ruled out a large gas giant such as Tyche, which was supposed to be in the inner Oort Cloud. A Super-Earth (smaller than Uranus/Neptune) there would probably not have been seen.
Nemesis (a red or brown dwarf) would have been even more visible in that kind of survey, since it would put out much more heat.
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Please re-read my post... And in case you have difficulty with comprehension, I was responding to TheGatesofLogic who focused on the fact that Plutonium-238 isn't fissile. I pointed out that, while it may not be fissile, it is still dangerous. Not only because it is radioactive, but becase it is also a toxic heavy metal. It is restricted by rigorous regulations for a reason.
Sure, it's quite dangerous, but the level of regulation applied to it is way out of scope for its actual danger. Even counting in the radioactivity, there are much-less-regulated chemical compounds which are far more dangerous (in terms of smaller LD50) like Botox.
Also, there's the matter of ease of exposure - an alpha emitter has to get inside your skin to be dangerous, while there are plenty of highly toxic chemicals that can slip right through skin (and some even through gloves like dimethylmercury). Benzene, a common industrial chemical, is a carcinogenic highly-flammable (flash point well below room temperature) which can affect people through skin exposure. Really strong oxidizers will react violently with pretty much anything, including common fire-extinguishing agents and even rocks. Etc.
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It would be a very short time on the geological scales. If all life was suddenly removed, it would take more, but in this case we just have the production stopped. There's a lot of reducers in the nature to reduce oxygen to water. All of the biomass on the world suddenly turns into exclusive oxygen consumers by rotting.
Sure, but the biomass is tiny compared to the mass of oxygen in the atmosphere. The CO2 levels might become problematically high, though.
Apart from organisms, consumers would be not only reductive compounds made by geological processes, but also compounds made by the bacteria. Amount of anaerobic bacteria below the silty ocean floors is enormous. Their metabolism gives off hydrogen sulphide and methane, and they don't care about what's happening above. There's plenty of food for them.
There may well be a huge amount of very deep endolithic bacteria, but I'm not sure whether their metabolic products actually enter the atmosphere or ocean, and anyway their metabolism is glacially slow (1 cell division per century kind of thing).
I don't think the ones interacting with the ocean in black smokers/cold seeps are that abundant since their habitats are small & localized.
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OK fine but what does that mean in practice, IE with the classic go back in time and prevent yourself from being born type examples? I thought field theory was a quantum thing not a macro scale thing. What does the macro scale reality look like?
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Yeah, that sounds very hopeful in terms of more realistic aerodynamics.
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The real problem is that stock turbojets are currently the best rocket engines for launching payloads less than 100 tonnes to orbit. Actual rocket engines can't compete, because turbojets have a high enough TWR and Isp around 40000 s. They should either be renamed to Magic Star Wars Engines, or their TWR should be nerfed to below any rocket engine and their fuel usage increased by 16x.
Yeah, exactly.
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But something I keep saying : KSP being unrealistic isn't always/just because "the devs don't know better", they do in fact know that if they made X or Y "minor feature" as realistic as some ask, it would not actually be as fun to play than what is said.In some things, I can see that, but I don't see why more realistic physics would make it less fun.
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I've always understood the very powerful EVA pack as compensating the absence of tethers. In the real world, astronauts are much safer from being flung off into space because they can pull themselves back. Kerbals don't have that luxury, so we get a bit more power to get around and get us back safely.
If SQUAD made it weaker there would probably be as many people complaining about all the kerbals they've lost tumbling into space with no chance of return
For me, though, it tends to lead to the kerbals getting lost in space since it's hard to control...
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So how are the paradoxes resolved?
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That kind of speed is still pretty dangerous to unprotected objects...
Oh, certainly, but the protection needed is a lot less extreme.
Make the MK1 command pod have a built in ablative heat shield as well if you like. then your first few flights will be more forgiving.
IMO both 'space capsule' command pods should have heat shields built in, but not lander cans - as implied by the "won't survive atmospheric entry" text on one of the lander can descriptions.
The spaceplane parts, IMO, should be able to survive hypersonic flight, but would have trouble with a steep reentry.
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I know at this point anyway, that the current out of Africa scenario matches the split and diversity of the ASPM allele, both of which happened about 50,000? years ago.
Sure, but that's not going to be affected by digging up of fossils over 1 million years old. Whether you think ergaster, erectus etc. are all one species or not, it's still a separate 'out of Africa' migration event from the sapiens one.
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When did 6U cubesats become a thing anyway? I saw them mentioned as secondaries on some other mission... I thought there were only 1U, 2U, 3U.
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I think the idea is that it could be used in a dirty bomb. In addition to being radioactive, Plutonium is a toxic heavy metal. The risk would, of course, depend on how much radioactive material the pacemaker contains. .
Lead is a toxic heavy metal too, but I've never heard of attacks using lead as a weapon... There are 40 jillion toxic things in the world.
EDIT: well, yeah, bullets are lead... but not because of its toxicity...
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Well, most of the oxygen removed now is due to animals & decomposing fungi/bacteria/etc, and these would die off quickly (many within weeks, scavengers/decomposers/detritivores would live significantly longer) due to starvation.
From a search, the mass of oxygen in the atmosphere is vastly greater than the biomass, so the rotting away of most life wouldn't reduce it much. After that, it would be geological processes, which are slow (most rocks are oxidized already).
A search gives me about 4 million years, but that's to remove all of it, and I don't know whether it's a linear decrease or what. But, very roughly, it would probably take hundreds of thousands of years for the oxygen to drop to unbreathable levels. Maybe longer depending on who you are -- if you live in the Andes or Tibet with low oxygen partial pressure, you might be able to live at sea level with a significantly lower oxygen concentration.
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I'm hoping for a modest form of re-entry. Dangerous if you come in stupid but fun designs can still work if you're careful about your re-entry path.
It should be pretty forgiving anyway, given that orbital velocities are at least 3x lower which means 1/9 the kinetic energy.
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I just updated to 0.90 and now the TWR of rockets seems too low. I have a 12.7 ton rocket on the launchpad and a LV-T45 isn't lifting it (I even right clicked on the engine and saw that the displayed thrust was definitely high enough, so it's not a throttle setting problem). Is this a bug or did they change Kerbin's gravity or something?
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The temperature in the reactor is going to be high enough to cause partial decomposition, the exhaust won't just be pure fuel.
Ok, but even then, I still don't understand why methane is so good. I don't see what it can decompose to except elemental carbon and hydrogen gas... but elemental carbon shouldn't be a gas at 3200 K (which is what those numbers are for). Looking for phase diagrams it seems to be at least 4000 K for gaseous carbon even at zero pressure.
So shouldn't the carbon be falling out of the exhaust as a solid and actually making your specific impulse worse by effectively losing 3/4 of the mass you put in (or ejecting it at very low velocity)?
Whereas ammonia should decompose to two gases.
Crops on Mars (minor "The Martian" spoilers)
in Science & Spaceflight
Posted
IIRC quite a few deserts and evaporating environments have perchlorates in soil on Earth e.g. in New Mexico. I don't think they're a game-changing problem for Mars. Something that needs to be considered and mitigated for safety, certainly, but nothing really crazy.
(From what I find, the toxicity of perchlorates is not that high. Potassium perchlorate at least was used as a drug to treat thyroid issues, and apparently still is in some countries. It is still toxic, of course, but as usual 'the dose makes the poison'.)