OMG, you fucking moron, learn something, read a book, go read some jokes, humour obviously is not your strong suit, but maybe you can learn to pretend you understand it, moron.

Before you younguns turn this into a "those silly Americans" thread, Colossus was absolutely essential to breaking the Nazi Enigma code and was classified during and after WWII. ENIAC was therefore regarded worldwide as the world's first general purpose computer. Everyone who went to school before 1996 was taught that ENIAC was the world's first GP computer.

Information about Colossus was first declassified in 1975, but it wasn't until 1996 (not coincidentally 50 years after WWII ended) that enough about it was declassified for the general public to realize it was in fact the first GP computer.

The problem with that is that nuclear power contaminates the turbines. Badly. You're heating the water that spins those turbines by passing it over a nuclear pile. You're not realistically going to be able to use them with any other heat source after that. But I agree about prebuilt, small-scale reactors being a better solution. In addition to having fewer quality control problems (for example, less risk of "oops, the pipes are wearing out dramatically faster than expected" situations like we saw with San Onofre), a smaller plant would also presumably be easier to deal with in the event of a serious failure.

So what you mean is the BIGGER computer? :D

Sure. Bring a laptop.

That may well be, but have you ever looked at a turtle's drag coefficient?

What you think of is wild speculation is just another day at work for a space systems engineer like myself. Going to the Moon was wild speculation in 1950, and a computer you could carry in your pocket was wild speculation in 1970. Fortunately progress doesn't depend on nay-sayers like yourself.

In orbit outside the Earth's shadow, you average 7 times the output for a solar panel, compared to the average location on Earth. That's due to lack of night, atmospheric absorption, and weather. If you can put that panel in place for less than 7 times the cost of a terrestrial one, you come out ahead economically to put it in orbit. Since launching stuff is expensive, you are more likely to reach that cost target if the panel itself can be made in orbit. Fortunately the average space rock is 40% silicon, which is what we make solar panels out of.

You are right that in 2014 it is cheaper to put the panels on Earth, but that may not be true at some point in the future.

No, the burn times are 110-465 days to return 200-1000 tons of material, plus coast times between burns. You can find the calculations at

https://en.wikibooks.org/wiki/...

200-1000 tons is a reasonable goal for early mining missions. If your chosen asteroid is larger than that, you scrape loose surface material or grab a boulder off it. Entire larger asteroids would require bigger power supplies and thrusters, so are best left for later generations. 1000 tons is a lot, that's twice the mass of the ISS. And you can fetch that much back every few years with a single mining tug.

Yeah, my stupid. Not sure what I was thinking when I wrote that.

-1, facepalm.

> There are things called lathes and other machine tools that can reproduce themselves.

Not unaided. Machine tools can indeed make parts for more machine tools, but they need a source of power, and a supply of stock metal shapes to do that (and eventually fresh cutting tools)

> The real question is how many of these kind of tools together with a good smelter do you need before you can be self-sufficient and keep making your own sets of tools out of raw materials?

We phrase the R&D question a little differently: What is the best starter kit, and best growth path from the kit to a fully expanded factory? We have a draft starter kit list at https://en.wikibooks.org/wiki/... , and it includes a lathe, mill, and press, which are basic machines, but there are several others in addition. The starter kit emphasizes flexibility by using attachments to do different tasks. The expanded factory can add more specialized machines as needed, since your starter machines can only do one thing at a time.

> it would be nice to get a set of these kind of tools into the hands of people in 3rd world countries

Providing starter kits for under-developed areas is one of the project goals.

> It is also something important to know about if you are planning on building a colony on Mars or the Moon,

If you can build 85-98% of your stuff from local materials, it dramatically reduces how much you have to bring from Earth. That has huge leverage on what projects are feasible. However, helping people on Earth is a more immediate and larger need. So space versions will be 3rd or 4th generation Seed Factories. The first generation design is for ordinary people right here on Earth.

It's almost like this is a very HARD PROBLEM that hundreds if not thousands of very, very bright people have been working on for years without much success.

Huh. Who'd'a thought?

(I think this entire project, while worthy, shows a staggering level of conceit, if not profound disrespect for brilliant scientists and engineers of previous generations. "Well, if we just get some smart people - I mean GOOGLE smart - and let them think about it, I'm sure they'll find the answer!")

Sometimes the historical ignorance displayed by people today is breathtaking.

Can God create a disk wipe so secure even He could not recover the data?

Dude, pass whatever you're smoking down the left hand side. ;-)

> Good for you! You are proposing to build an actual von Neumann machine.

The idea of a Von Neumann machine assumes 100% automated and that it copies 100% of it's parts exactly. We don't make those assumptions. Human labor is allowed in the Seed Factory concept, whether hands-on, or by remote control for space versions. Some parts will be too hard to make internally, like computer chips. Other parts will require rare elements that are not available locally. So those items are simply bought instead of trying to make them in-house. We think a reasonable goal is 85-98% internal production by mass, depending on location. Lastly, we don't replicate (copy our parts exactly), we expand by making parts for new machines not in the starter kit, or by building larger versions of existing machines. If you want to, you can eventually produce a copy of the original starter kit, but that is after a period of growth from the seed to the fully mature factory.

> Any estimate on when we will see this is more than just an electronic document?

Our Seed Factory Project [ http://www.seed-factory.org/ ] has purchased a 2.67 acre (1 hectare) R&D location in the Atlanta metro area. We are starting to install a conventional workshop, with the intent to build prototypes of the starter kit machines. We plan to collaborate with local area Maker groups and hopefully institutions like Georgia Tech. Our designs will be open-source, which is why we are using Wikibooks and similar sites to document things.

> the WikiBook about this flys at such a high level that it is impossible to tell whether there really is anything here.

You are quite correct. We need to get to detailed designs and calculations, and prove the ideas work in practice. That's why we are setting up a physical R&D location.

> Water is... difficult to find on most rocky and metallic asteroids

Water as water is rare in Near Earth Asteroids, because their average temperature is too warm and it sublimates away in a vacuum. However, water in the form of hydrated minerals can survive up to several hundred degrees C, and is present in concentrations of up to 20% in Chondrite type asteroids.

> I'm betting that more conventional construction is more likely for a first few tries.

It's a bootstrap process. You start out with the easiest items to make from asteroid rock: bulk shielding, water, structural iron, oxygen and hydrocarbons for fuel. At that level you bring ready-made processing equipment. Then you bring machine tools, 3D printers, and the like, and start making other processing equipment. Gradually you make more things locally, and import less. About 2% of your items will either be hard to make (like computer chips), or require elements that are rare in asteroids or other space locale. You continue to import those items, but 2% beats having to import 100% by a huge margin.