Seret

Population of what? If you mean normal unmodified Earth humans, plants and livestock then no I don't think it would be habitable. If the mix of atmospheric gases is different then crops won't thrive and people can't breathe properly. I am however not a planetary scientist so this is a bit of a guess.

Sure, the OP wasn't really specific about their definition of "habitable". Technically a world consisting entirely of seabed covered in black smokers is habitable, but I'm not sure that's what they were getting at.

Which is why reprocessing is so controversial.

Absolutely not. My workhorse for all operations in the Kerbin/Mun/Minmus system is the Space Tractor, which has exactly that.

Have you dropped a stage just before your gravity turn? It sounds like the stage you've got firing has insufficient TWR. This is not uncommon for upper stages, I find the Skipper engine often needs to be augmented slightly with radial engines to get the TWR up high enough. A mod such as Kerbal Engineer or Mechjeb is needed to display the TWR of your stages while still in the VAB (or you could do it by pen and paper...).

It might be broadly habitable, but it wouldn't be exactly like the Earth. Things like the balance of gases in the atmosphere depend on cycles that include release and sequestration of gases by geology and the sea. It's a complex system, change the parameters too much and you can tip over into wildly different equilibria than our current one. So the planet could be habitable in terms of things like gravity and radiation, but I'd be surprised if the atmosphere was healthy for us to breathe.

Nuclear power plants are often built next to bodies of water, to give them access to coolant.

Download Ubuntu and put it on a disk or usb stick, instructions for that are on ubuntu.com. You can boot up into that and give it a try before you change anything. Once you're happy hit the install button and the installer will walk you through it. It's easy, and you can even surf the internet while it installs. If you have any specific questions try ubuntuforums.org or askubuntu.com.

Besides the exhaust high neutron flux will induce radioactivity in everything nearby, such as the structure of the engine.

Reprocessing is expensive and presents a proliferation risk. Unless you're specifically looking to obtain plutonium for an arms programme it's generally better to just leave the spent fuel intact and burn fresh stuff.

Definitely. There's always an arms race going on between armour and warheads. Vehicles have started using composite armour, reactive armour and active armour, and missiles have responded by doing sneaky things like tandem charges to deal with ERA, and top attack to try and hit where the armour is thinner.

There are two ways to stop a missile: Active: Fire another missile or a projectile weapon to destroy the incoming missile. Passive: Use ECM, decoys and maneuvering to try and defeat the missile. Technically there's another passive method: armour. But this isn't going to be an option on spacecraft due to weight limitations.

What they actually do is vitrify the waste (mix it with melted glass and cast it into a block, essentially). This then gets packed into metal capsules and packed into clay.

Geological repositories do make sense, but aren't without their own problems. Transport is a big issue. Are you suggesting we use the Yucca Mountain site for the whole world's waste, or just that from the US? Who's paying? And how do you get the waste there? While not particularly challenging technically the practical, political and regulatory issues of centralised storage are vexing. Which is why it's not really happening. There are a couple of small repositories taking waste from a limited number of sources, but nothing large scale or coordinated.

It's completely possible, but what difference would it make if it were true?

Good luck with that...

Some cancers will still be dangerous at that point, definitely. There is no one cure for cancer, because it's not one disease. We can deal with some cancers very effectively already, some we can do very little about. Unless there's a fundamental breakthrough in how we treat them, it'll just be a gradual process of sifting the ones in the "bad" pile into the "not so bad" pile.

That, indeed, is my point. I don't think it's at all feasible to sustain the level of investment required through that business model. It's certainly extremely risky, you're basically betting the lives of a group of people on the whims of the TV-watching public. How would you feel about a show where they promised to shoot the participants in the head if you changed channel? Because that's essentially what Mars One are proposing. It's just a hunch. A TV show about Mars One volunteers going through their training is very much achievable, and IIRC Mars One are in fact planning on producing one. Doing so would be well within their technical and financial capabilities. An actual Mars mission comes somewhat later in their timeline and would cost vastly more, therefore it would only get green-lighted if they were projecting that they'd make enough money to cover it. Since I don't expect them to be earning enough money, I would expect them to wind things up before then. The cynical part of me judges that they expect the same thing to happen. It's a pretty flaky business model, after all. I'd be more worried about their sanity if they really thought they'd get anybody to Mars that way.

Guys, if you want stuff like this changed in the game you're much more likely to get a result from filing a bug than you are from making a forum post.

That's about the size of it. However, what would be considered worthless junk on Earth is actually high-value junk in orbit purely due to the mass-to-orbit cost. At current prices a paperclip in orbit is worth about US$14. As for 3D printing, it doesn't work that way. You can't just mash up a collection of various different metals and non-metals and feed them to a 3D printer. Sorting the materials accurately, separating them into their component elements (how?) and turning them into a powder suitable for metal ALM would be an incredible process requiring huge amounts of hardware, operating in orbit in zero-g. Not happening in our lifetimes, folks. Easier just to pick out one easily sortable metal (steel?) and use it to make relatively low-energy low-strength products like extrusions or rolled plates. The poor homogeneity would mean it could only be used for non-critical applications.

Hmm, first graph is of power density, second is of energy density. Not exactly the same thing. However, the OP does have a point. The reason hydrocarbons are so useful for transport fuels is their high energy density. Despite this, we don't use it as our only energy storage solution, trying to compare it to electricity storage is really only relevant when you're looking at electrification of transport. There are a few different challenges when it comes to energy storage: Grid-level storage Local or domestic Transportation fuel (road/air/maritime) Mobile electric/electronic devices Storage for heating/cooling (which may or may not be electric) We've got solutions for some of these, but not others, and they all could do with improvement. No one technology is going to be useful for everything.

A general tip: always do all the actual data crunching in nice metric units, then convert to imperial at the end if you have to. (Assuming your original data is metric, of course...)

Because based on the only solid data we have such missions are less likely to succeed. It's logical that the first places we look are the places that we know for certain are viable.

Watch any sci-fi movie about space combat, then imagine the exact opposite.

You're expecting a team of amateurs to build a launch complex, prepare a rocket for flight using pioneering tech like ISRU, and carry out docking? As for reality TV shows: how long do they generally stay profitable? Because assuming you send relatively young astronauts you're looking at committing to fund the outpost for several decades. It would take the most successful reality show ever made to even come close to success. I'm highly sceptical that Mars One's actual business plan relies on such a wildly improbable event. As I said earlier I don't think they've got any real intention of going to Mars, I think that's just the hook for a very terrestrial reality TV show.