Nibb31

That's a small galaxy. Our own galaxy is thought to contain over 100 billion stars. You should start off with your book and invent whatever you need as the need arises. A galaxy is big enough for anything to exist.

I think his question was why this silly thread got promoted to "thread of the month". For example, the Juno thread seemed more worthy...

In theory, government property cannot be sold without going through an extensive process. Most of the artifacts from the space programs were either given away (tiles from the Shuttle program, pieces of kapton from Apollo, etc...) or stolen (even if it was stuff that was to be trashed or that was forgotten in a closet, it was still government property). The astronauts themselves got to keep a couple of bits and pieces from various craft, some of which were sold for quite a hefty sum...

Not necessarily. There are lot more electronics on this Soyuz than on the previous one (sat comm systems, sat nav, docking, etc...). There is also an electrical mechanical assisted docking system that might require more power.

The updated electronics systems require more power.

By that standard, it's a wonder there are any inhabitants in the UK Remember that human migration happened over thousands of years. Regional climates changed several times over the period. Sometimes colder regions are more fertile or safer than warmer areas. As local conditions changed, some populations moved on whereas others preferred to stick around. In addition, war/demographic/cultural pressure sometimes means that a less fertile/colder place is still safer or more pleasant than a place where you can get killed or persecuted. The point being, human migration has only been driven by the idea of making a better life, safer and/or more comfortable. Space is neither of those.

Of course, the difference being that migration has always been dictated by greener pastures, richer environments, better living conditions, safer and more comfortable habitats. Space is the exact opposite of all that.

Living in self-sufficient colonies where the lives of thousands of people is going to rely on the scarce minerals that you can extract from asteroids is going to require strong discipline and management. If you want O'Neill colonies, you are going to have to go sustainable, to keep population levels manageable, to learn to live with limited resources. Expanding out into space doesn't suddenly give you infinite resources. It only expands the limits temporarily until you reach new limits. Living in space is always going to require a much more frugal life than living on Earth, simply because the resources are going to be rarer and less diverse. Sustainable development is going to have to happen, whichever path we choose, otherwise we're screwed. If the betterment of living conditions for human kind is the goal, then that's easier to achieve by reducing our numbers. Wouldn't it be better for us as a species to be 2 billion living in relative comfort than 20 billion and forced to live in container modules in an artificial environment? What is the point of increasing population if everybody's standard of living suffers from it. Expansion for expansion's sake is pointless. That sounds a bit ethnocentric. What's wrong with living in Africa?

Please tell me you're joking.

What makes you think it is capable of landing anywhere? Does it have an altimeter? Does it have enough dV? What purpose would it serve to land it? It's really annoying to see people on a game forum think they have it all figured out better than those stupide folks at NASA/JPL who have been studying projects like these for decades. Who do you think is better qualified for designing an end of life manoeuver? A bunch of kids doing a poll on the internet or a top notch team of some of the smartest astro-scientists in the world? Hmmm...

It's not a very new concept. Similar ideas have been floating around for ages. The reason it hasn't taken on is because it's simply not a very good idea. Modern airliners can already be palletized (some 737s are converted to transport mail at night and passengers by day by switching palettes). At a time when airliners are getting more streamlined to save 0.01% of fuel, this goes in the opposite direction. Also, this is not going to be a time saver for passengers. Instead of boarding the plane and taking off, you will need to board the module, attach the module to the plane, check everything out, and then take off.

It doesn't have enough thrust to land.

By that standard, we also have the technology of warp drives, time travel, and cryogenic hibernation. At this moment, closed-loop biospheres, orbital manufacturing, mass launch systems, asteroid mining, or even artificial gravity are on the same level. They exist merely as notional concepts, not even lab models or sub-scale demonstrators. In no shape, way, or form, can those concepts be considered as actual technology that we can use as a basis for real-world applications.

That's really cool. I didn't know of that website.

Yes, most probes communicate through NASA's Deep Space Network, which is currently made of 3 stations (Goldstone US, Madrid Spain and Canberra Australia) and is shared by all the ongoing unmanned projects (including Cassini, various Mars missions, etc...). Each project is allocated slots for using the DSN, which vary depending on the bandwidth, the distance, and communication windows. Each antenna can only communicate with one probe at a certain time, windows open and close as the Earth rotates, and the 70m et 34m antennas take a certain time to be pointed to a new target, so each project has to take turns when it comes to sharing the DSN assets. These stations also have downtime for maintenance, repairs (some of the antennas are quite old). The limitations of the DSN are one of the main bottlenecks for unmanned exploration projects, and one of the reasons legacy programs have to be cancelled to make room for new ones.

TRL 2 is the point where practical applications haven't even been invented yet. Which means that the technology is still only a theoretical concept that might be rejected before it ever gets to TRL 3. Ie. It doesn't exist. We're going to have to agree to disagree here. I'm agreeing with NASA.

Not really. The hardware is exposed to extreme condtions. The philosophy for this sort of mission is to maximize science returns as early as possible, because the older the hardware gets, the more chances you have of it failing. Shutting down for 6 months means a 50/50 chance of it not waking up in 6 months, which would make it rather final. If it doesn't wake up, then you have wasted the opportunity to get from 1 to 6 months of science return on an expensive piece of hardware. As I said, it's not a decision any more. The thread is 3 years old and Cassini is ending in 2017.

There is no issue. If there was a budgetary choice to be made back in 2013, it has probably been made by now. However, maintaining missions has a certain cost: you need to mobilize a very specialized and expensive workforce to run the mission and analyse the data, you need to maintain mission control facilities, and access to the DSN, which is also expensive. It's not so much a matter of budget as it is having several projects competing to use the same assets.

Which is why I deliberately used the notion of Technology Readiness Level as used by NASA, DoD, ESA, and other technology players. "We have the technology" means that you can actually start planning to implement engineering solutions that are based on it. Basically, when you get to TRL 8 or 9. None of the technologies required by O'Neill colonies are beyond TRL 1 or 2, meaning that we haven't even done the basic trade studies or any preliminary engineering. In other words, we don't know whether they can actually work, whether they are feasible, reliable, cost-effective, or whether they will end up being moot or dead-ends. Having just a vague theoretical concept about how something might work is not the same as having the technology, whatever the definition that you use for that word.

Sure, it would mean diverting precious resources (time, money, workforce, energy, consumables) from everything else that we spend those resources on (infrastructure, education, social cohesion, research, peace, police, justice, etc...). I'm not sure what state the world would be in after that. It's easy to decide that your pet peeve cause deserves that the entire world sacrifices itself. The hard part is deciding which causes you are going to sacrifice. This is the same for pretty much every government on Earth. Deciding that a new policy needs funding is easy. Cutting the funding for existing policies to pay for the new one is the hard part. Everyone wants free beer. Nobody wants you to pay for it by closing schools, abandoning roads, cancelling research projects, and shutting down public services. No we don't. Can you remind me of the TRL levels for asteroid mining, closed loop life support, artificial gravity, cosmic radiation protection, long term habitation, super heavy launch techniques, orbital construction. Anything below a TRL of 8 means that we don't have that technology. At best, those things are at TRL 1 or 2. "If we really dedicated ourselves, we could develop, maybe, perhaps, in the future" = "we don't have that technology". Just like all those other resources, that steel is used for thousands of other useful applications. Which ones are you going to give up? Do we suddenly have to stop building all other steel-based products that are required to develop the economy. But why would we dedicate 8 billion people to a project that would only profit a small number? What about the consequences of halting pretty much every other major project in developing countries and putting the World's economy in standby mode while you do this ? The social, political, and economical consequences make it definitely not "doable".

We don't have any of the key technologies to build self-sustaining space colonies. All we have is a couple of theoretical ideas, but the TRL is way below 2 or 3 for most of them. Neither could we realistically fund the construction of such colonies if we wanted to. Space colonies, at this stage, are a hypothetical construct at best, so there is absolutely no basis to claim that they could sustain 8 million people. There is also no rush to start now. Statistically, the difference between an Earth-destroying "unexpected disaster" that hasn't occured in a billion years happening in the next 50 years, vs in 2000 years is practically nil. We would be better off spending our efforts on fixing the expected disasters that are going to happen over the next couple of decades.

Rome attempted to have Carthage erased from the globe after the Punic Wars. However, it's hard to destroy an entire city without leaving any trace at all. The location of Carthage is well known (in Tunis) and you can visit the ruins and see them from Google Earth. Any advanced civilization would leave some sort of archeological clues behind.

Assuming that they didn't get past the neolithic (in which any evidence would be glaringly obvious), we would still find fossil traces of tools or clothing or any other changes to their environment or habitat. Another possibility is a species that could develop language and communication, but without the ability to manipulate its environment. Like dolphins or whales, they could develop a strong oral culture, possibly richer than ours, but without opposable thumbs or any manipulator organs, they could not develop any technology. So long and thanks for all the fish.

Radar

I say that when the manure hits the impeller, there is less chance for a government to be concerned about colonizing space than to start worrying about birth control. Money, since every other resources can be measured by that. You think governments (or in a larger scope, society) will be more likely to pay for space colonies than for birth control and education? I agree that neither are very likely (which is why I deep down believe that the next generations are prettty much screwed at this point), but Rubbish. Birth control pills exist and can be manufactured for cheap. Space colonies don't, and would require a massive industrial effort beyond anything humanity has ever accomplished. And every decision boils down to the political, economical, and social incentives, even the relatively simple engineering ones. You don't need space colonies to preserve our gene pool. Just freeze some embryos, bury them in a vault in Antarctica, and bring them back with robotic nannies when the dust has settled. Absolutely. Enjoy the pleasures of life for what they are and for the time that they last. There's a lot places to visit, a lot of people to meet, a lot of fun to be had. There is no purpose. Assuming so would mean that there would be some sort of superior conscience that has a big plan. There isn't. That's not how nature works. The Universe has no purpose. It just is. I guess so. I'm going to die one day, so I'd rather make the most of the little time I have than waste time on worrying about ways to live forever. Hmmm... The "postwar" period (which incidentally has been one of the bloodiest periods in human history) represents 50 years of the 200000 years of existence of our species (99% of which was spent hunting animals and picking roots and berries). Isn't that like trying to extrapolate a future trend based on the last few minutes? On the geological scale, Humanity's demographic spike over the last 200 years, and the ecological disaster that has been the consequence of it, looks more like the anomolous surge of some sort of passing disease than a mutation that is sustainable in any sort of ecosystem. I'm willing to believe that the rash or fever will be all over in a century or two, just like most virii or pest infestations die out by themselves once they've exhausted their host.