NERVAfan

What is the current status of this?

Why not? Algae is great for oxygen production, as are some water plants like Azolla - they would be great for space life support systems being very fast growing/photosynthesizing. I think these would be ideal. Water is heavy, yes, but it doesn't need to be very deep at all. True, but a frost might kill a land-based plant too, and water is slower to change temperature than air.

For fast growth, I'm sure. But wouldn't it survive anyway, just grow slower? EcoSpheres have kept algae in them (small sealed containers) for years with no pumps or anything. If it was a 2U I'd suggest actually sending an EcoSphere, but unfortunately the smallest one is 4 inches. OK, maybe I'm missing something obvious, but if you have plants floating in a sealed container, why would tumbling it be a problem at all? It'll just travel with the water. As long as it's sealed on all sides so that the water doesn't spill out... I can go put algae or duckweed or whatever in a container and spin it around, juggle it etc. to see if anything happens, but I really doubt anything will. I think submerged might turn out to be easier.

Nah, there are also duckweeds (Lemnoideae or Lemnaceae) of various types. And tons of kinds of algae, lichens etc. if you're going to spread your definition of 'plant' wide enough.

If we were going to use water as the medium anyway, duckweed (another extremely tiny plant) or algae would make more sense, I think, as they can grow in full sun. I don't see why growing it in water would make it harder, as long as it's in a sealed container so the water can't get into any of the electronics.

OK, yeah, good point, the gravity would have much less of an effect on algae suspended in water. Why moss though? Moss is generally shade living, how well will it do in full sunlight? I'm not sure that is a good test of the gravity aspect since the sunlight may kill it/prevent it from growing much? What species of moss would be used?

We could have a list (generated by us) of 10 or so names and the highest Kickstarter reward could be to pick one as the final name. Also, small stuff like cubesats have their orbits decay much faster than big stuff like the ISS in a similar orbit, I think because of surface area/mass ratio (square cube law).

I just found out about this and I haven't gotten through all 110 pages (sorry if I'm repeating something), but... ...I would suggest that instead of moss we could send up algae in a small sealed transparent container of water. Having our "plant" floating might help with the direction of 'gravity' changing between launch (rocket acceleration) and spinning-artificial-gravity: if we use plants in soil soil might end up falling in weird directions. But a sealed container of water shouldn't be affected much, the water would just find its level in the new gravity. Is water allowed on cubesats? EDIT: that's probably a dumb question, sorry. EDIT: This would also help with keeping it pressurized if the algae & water were in a sealed container of their own. And it could be made very small since the algae are microscopic individually (but visible en masse, so a camera can see them). I'd suggest filamentous algae ("pond scum") - they're basically aquatic "weeds". It would be great to use Arabidopsis thaliana - it's the classic experimental plant (just like fruit flies and mice for animals, E. coli for bacteria, etc.) But while it's 'small', it's not THAT small. EDIT x2: and we'd need an identical container of algae (or moss or whatever) on Earth.

You don't need anything fancy for a Sedna flyby (well, RTGs are needed, but not necessarily reactors or ion propulsion)... just patience. The Voyagers are farther from the Sun than Sedna is now, and are still functioning. Nuclear-electric is definitely an option, but launching an actual reactor into space is possibly politically shaky. The more exotic possibility is a solar sail with a very close Sun flyby to get a huge push. I actually think strong AI stuff (especially self-replicating!) is probably too dangerous to mess with, at least until we have off-Earth bases where the research can be done (and not just ISS, electronic communication is too quick/easy; I'm talking far side of the Moon etc.) The risk of strong AI going bad may be comparatively low, but the costs could be colossal, and we don't even know that the risks would be low (look how violent humans can be - I rather doubt we could make/teach something to be better than we are). And the benefits are small/nonexistent, or at least not really good for humanity/civilization in the long run even if they weren't hostile - they'd either end up replacing people or being slaves, IMO. So the risk/benefit ratio is very poor. EDIT: Though I'm far from convinced AI (in terms of "computers" - not engineered biological brains or something) is even possible (and I hope it is not, for both practical and ethical reasons).

Actually, the center of the Earth - the inner core - is indeed solid; it's the outer core that is liquid. (And the core is mostly metal, not rock.) Having solid phases at really high pressure/temperature isn't that odd; it's the liquid and gas that go away and become a supercritical fluid. Stars' cores are plasma, yeah, but they aren't just heat+pressure, they have the outward radiation pressure from the fusion holding them up against gravity. When the fusion stops they compress into electron-degenerate matter (a white dwarf) or the even weirder stuff that a neutron star's made of.

Ah, OK, thanks... I couldn't find a way but the description of the Clamp-o-tron Jr. says that you cant' transfer crew because it's too small... which implies that the larger ones can... but if it's just not implemented yet, that makes sense.

Is it possible and if so, how do you do it?

I don't know what Coruscant's population density is supposed to be, but I think you could get "sparse city" population densities over a whole planet to work (without importing food) with algae farms and such, especially given genetic engineering. If all photosynthesis on Earth was used directly to produce human food (and everyone was vegetarian) you could get enormous numbers of people. This would also provide oxygen for everyone. And there is probably room for genetic engineering to increase the efficiency of photosynthesis (which is quite low). It wouldn't be a planet with literally nothing but skyscrapers, but it could be pretty dense. I don't know how much of the problem the heat would be... but you could build it on a planet that started out cold. It would totally destroy the existing ecosystem though. EDIT: I think the heat could be gotten around because the population I'm suggesting would probably be in the hundreds of billions range (which is likely less than Coruscant) and because this civilization would probably use much less energy per person for living needs than, say, the US. The algae is grown by sunlight, not artificial lighting, and there probably aren't actually mega-skyscrapers, which are a transportation problem -- the population density wouldn't be high enough to require them.

This would be very cool.

Essentially, though those lifeforms use chemical energy (chemosynthesis) rather than thermal gradient in the way a thermocouple would -- the black smoker is releasing the sulfur compounds etc. used.

There is far more involved than that. They'd have to be able to deal with Earth's oxygen levels (or be limited to anoxic niches). They'd have to be able to feed off Earth life, which would have a different set of amino acids etc. (Europan producers would be limited to very narrow niches like black smokers/cold seeps on Earth - they wouldn't photosynthesize). Even if they COULD feed off Earth life, at best they'd take some decomposer niches. "Bacteria" aren't just one niche, so replacing Earth bacteria in decades is not possible. Europan life would never replace e.g. photosynthesizing cyanobacteria, they wouldn't replace bacteria that are symbiotic with plants or animals, and so on. Also, there are several different respiration mechanisms used by Earth microbes, do we know they haven't already found the "optimum" (at least assuming a sensible environment e.g. no free fluorine for respiration)? EDIT: Anyway, my original point was about pathogenicity not being plausible. Competition is possible (though I think unlikely) but it wouldn't rise to the scale of replacing all bacteria or anything like that.

Protons in different atoms generally don't (barring extreme circumstances like nuclear fusion, alpha particles hitting nuclei, etc.) as I understand it. Solid objects are solid because of electromagnetic interactions, not nucleus stuff.

People have put rats in centrifuges for two weeks. There were some effects (bone changes, newborn rats grew slower), but they didn't keel over dead or anything http://www.ncbi.nlm.nih.gov/pubmed/10776448 http://www.ncbi.nlm.nih.gov/pubmed/10776449 http://www.ncbi.nlm.nih.gov/pubmed/12124181 However, major caveat there -- small animals can get away with things big ones can't. So it might be worse for humans. Drop a mouse off the Empire State Building and it should land safely (unless a hawk grabs it on the way down) -- it's small enough that its surface-area-to-mass ratio is is high, giving it a low terminal velocity. (Cats are borderline -- they are well known to sometimes survive very long falls, but they break bones, and some do die.) Well, if you were walking around on Mars with a spacesuit, the total weight wouldn't be that much less than a person on Earth - current spacesuits are very heavy. There is work on much lighter ones though so by the time we get there, who knows? Also, you could just wear weights (some kind of harness distributing weight around your body) to keep up your strength (have earthlike weight) while in the pressurized habitats etc.

I don't think it could present a biological hazard either way. We don't worry about weird Antarctic or endolithic microbes causing plagues when scientists study them. Even if there was complex life on Europa that was biochemically similar/identical to us, and pathogens attacking that life, it would still be really implausible ... most human diseases "jump" from other mammals, occasionally birds (like some influenza). And even if Europan life was from the same origin as Earth life, it'd pretty much have to be transmitted as something like endoliths to survive a trip through space, and so it wouldn't be any closer to us than archaea are. And if it's NOT like our biosphere chemically, then it's even more implausible that it could be pathogenic. Now, alien bacteria could still produce chemicals that would be toxic to us if you ate/drank something with those bacteria in it... but actual infections are insanely unlikely. --- I don't think any life on Europa would be related to Earth life, though. I'm kind of skeptical of even endoliths surviving both the extremely energetic impact needed to hurl them to escape velocity and the probably extremely long time in space waiting to randomly hit a potentially habitable world (which are tiny compared to the size of the solar system). And Europa has an extra obstacle, Jupiter's incredibly strong radiation belts (admittedly, being inside a rock would provide some shielding, and some bacteria are quite radiation resistant).

I strongly disagree. The nuclear engines in KSP actually have their thrust weakened compared to real life, IIRC. And nuclear engines (NERVA type, which don't emit radioactive material in their exhaust when functioning properly, as opposed to something like an Orion nuclear pulse drive*) are a perfectly good idea in real life. *Although nuclear pulse drives actually make sense for in-space use for manned missions to the outer planets and beyond.

There's some sort of issue with a minimum pressure in the alveoli to breathe effectively, which is why spacesuits that use pure oxygen are pressurized to much higher partial pressures of oxygen than actually exists at sea level (much more than 3 psi). I don't understand it completely, but you can't just use an oxygen mask at really low external pressures. http://en.wikipedia.org/wiki/Space_suit#Operating_pressure

I think that would be hard to have something big enough to be a proper planet stay out of shape for long (geologically) after a big collision; Vesta is like that in our solar system, but I'm not sure how much bigger it could be and still work that way. It would be nice to have a Vesta-equivalent near Dres' orbit though... as well as making random asteroids appear there as well as in Kerbin-crossing orbits. However, you could have a planet of any size distorted out of shape by having a fast rotation, causing the equator to bulge outwards. I'd never get there, but that would also be cool, to have something for the people who have already returned from Jool's atmosphere and Eve's surface. --- I'd kind of like to see a super-Jool big gas giant or small brown dwarf at the edge of the system, with moons.

Laythe is a city inside the Moon in an Edgar Rice Burroughs novel (The Moon Maid).

I'm not sure the shifting time perception speed thing is real, or at least universal. My time perception seems to shift based on "deadlines". Time passes 'faster' on vacations, but it seems to be generally slower now that I'm out of college and don't have semesters to compare everything against.

Yeah, one showed up immediately after my first orbit. That did seem odd...