I remember reading about this kind of thing in the mid 1990's. Scientific American reported on it. At the time, they were making diamond films on ceramic substrates. the diamond was grown by creating a carbon atom plasma and shooting it at the substrate. Shock plasma deposition of the carbon. It wasn't very efficient. They hadn't worked out too well how to mask and etch the films, so they were using electron beams tp cut into the diamond, then adding the dopant. That limited the size of the device produced. The device was around the diameter of a pencil eraser. The researchers (in Japan, if I remember correctly) were predicting commercial development in as little as five years. Well, I never saw anything come of it.

I was looking forward to that coming out too. I am an electrical engineer, and have worked for a long time with plans for building facilities and power lines and so forth. The device made in Japan was a single SCR (silicon controlled rectifier) that would work just fine at 600 Volts, and a little over 200 Amps. It operated at a temperature of a little over 600 degrees C, but still, an SCR can be used for many power applications. That single SCR was controlling a around 120KW. For big AC to DC power lines, we use SCR banks where each of the SCRs operate at about 24 Volts relative to the next SCR in the stack. This for stacks that go up to 750 KV. The stacks are paralleled to get the current that actually goes out over the line. One such line goes from Washing State to LA, and carries close to 10% of the total power used by LA. for what I was doing at the time. These diamond SCRs would have made a great speed control motor starter. At 480 VAC, we could have made the controller with six SCR's, three fuses, and a disconnect switch, plus a small PLC board. The control station would be bigger than the controller. Typical controllers for this type of application on say a 100 HP motor are around 7 feet tall, 4 to 10 feet wide and 3 to 6 feet deep. reducing this to 2 Feet wide, 3 feet high and 1 foot deep would free up a lot of space. This, if purchasable, would have given me a lot more freedom in placement. If I could reduce the size of the controller, the process people would have loved to use the extra space. I could have used that to justify spending up to $100,000.00 more for the device, in some cases.

We could really use such a device in industry. There are a ton of uses that I could think of off the top of my head. Used as an ultracapacitor controller, it would enable a single capacitor, the size of a couple of C cell batteries to store more power than a car battery. A large electronically controlled circuit breaker, with custom controls, and a quick action would also help to save a lot of equipment and lives.

There were a couple of real problems with it, though. First, it's flammable. The actual electronics would need to be isolated from any contact with oxygen. Encapsulation would do that. Real Graphene computer chips, which I would expect to see before this matures, would also be flammable. But, there are more options for protecting those, because of the relatively lower temperatures.

Also, the Diamond SCR's operated at temperatures higher than some common conductors can withstand, and well above the temperature at which Diamond burns. There would have to be special connectors, and cooling systems. That heat, even if from a small eraser sized element needs to go somewhere. Ultimately out into the environment.

Second, it's apparently not an easily commercialized process or material. I am seeing more reports of Diamond film growth, and also of graphene film growth and production. That is a good thing. Graphene seems to be moving towards fabrication faster than diamond. I would like to see both happening. I have also seen recently, that very low impedance conductors have recently been made from carbon nanotubes. While not room temperature superconductors, if they have lower conductivity than copper, I would really like to be able to specify them. Cost would be a factor there. But, cost can be accounted for, if they deliver a performance maintenance advantage I run in to this all the time with choices of copper verses Aluminum for building wire. If they can be used as superconductors at near to or higher temperatures than the liquid nitrogen superconductors, then they would be able to fill a need also.

If these things can all come together, we will see more changes in the next 10 years than in the last 10, or even 20 years. I hope we do.

Forget Di-Lithium, we have Diamond Semi. The real thing!

He is also the only Geologist to ever walk on the Moon.

"electricity is nearly useless for lifting spacecraft in all models except Heinlein's imaginary mass drivers."

Actually, it is really easy. The higher the acceleration, the shorter the distance required. The energy is easily supplied by solar power. Add a capacitor bank, and a much lower peak power is needed. Your figures are for peak load. If the launch is not a continuous operation, then average power is sufficient.

For a 100 KG payload, at 20 G, (200 M/S^2) that would take 12 Seconds (2380/200) to reach the velocity you quoted. That's at 20,000 Kg M/S^2, or roughly 20 Kilowatts. double it for inefficiencies, and you get a 40 KW power source needed to deliver a 100 KG payload to earth every 12 seconds. At 25% efficiency, in the 1 KW per square meter sunlight on the Moon, that's 160 square meters of solar cells to launch using "imaginary mass drivers" that are already installed on Navy ships. Granted, the barrels for this system would be long. (200 X 12^2 /2 = 14,400 Meters), but if you increase the acceleration, you decrease the track length. The payload could withstand easily an acceleration of 10X that. People, not so much. It's long for a gun barrel, but not bad at all for a rail line. It's not like the thing has to be pointed straight up.

It would be a waste to ship fuel from Earth You are right there. But, that won't be done, except in very small loads in the first few years.

Rail guns are being developed right now that would do for shipping insensitive materials from the Moon to the Earth. They are being installed in Navy ships today. Power is just a question of finding available surface area and having a source of silicon or carbon to use in solar cell manufacture. The Moon has lots of silicon. You also need aluminum, Also very common on the Moon.

Surface area is not a problem either. Most of the Moon is unused. So is a lot of orbital space. As the Hitchhikers Guide says, "Space is really BIG!" Lasers and microwaves are being developed to move power from place to place, and are now to the stage that the Military is seriously considering satellite based power purchases. It's expensive, but they think it will be cheaper than the alternative. It currently costs more than $100.00 per gallon to get fuel to the front lines in Afghanistan. That makes generator power very costly.

But, I don't believe that Helium mining will ever be anything more than a byproduct of other minimg and manufacturing on the Moon. In that, I agree with you.

Gobi Desert. Already been done. It is called Mongolia.

For a similar desert scene, a little closer to home, you might want to consider Phoenix. Has the same extreme temperatures, the same arid conditions though winters are milder. Summer is hotter than in the Gobi. Phoenix is easy to find. Just go to the Grand Canyon, then head south until you get to a really big city.

A Moon base would need to have orbital farms to be really sustainable. Big rotating cans with windows would be all that's needed there. The two week day and night cycle on the Moon would be a real killer for plants. But, people could deal with it. Life there would be much like living in the Mall. Lots of Kids do that anyway. For a few months at a time it's OK. Probably wouldn't want to leave people on the Moon for long er than 6 months before roatating them to earth normal gravity anyway..We don't want their bones to soften.

That's why you ship a prototyping unit to the moon. Build everything else on site with local materials. It takes a bit longer, but it's orders of magnitude cheaper.

New York wasn't shipped intact from Europe, not even the majority of the materials were shipped from there. Only a little material that couldn't be made here at the time. The rest was of local manufacture. Why should a colony on the Moon be any different than a colony an ocean away?

Forget Helium 3. If you can build a mining operation on the Moon, you can ship anything back to Earth for little cost.

Build oxygen/aluminum-carbon rockets. Use them to launch payloads on an earth intercept orbit.

Build basic aeroshells with heat shields. Load anything you like into them. Have them land anywhere on Earth. Pick any lake, if they float, then no landing gear is needed. Tow the thing to a dock, and cut it up. Recycle the entire mass. Iron, aluminum, copper, silica, glass, rare earth elements, it's all gravy. If the asteroids are factored in, then you could ship oil back too. some asteroids are up to 40% oil. How many cubic kilometers do you want?

A couple of hundred people living in Space/on the Moon could pay for the entire space program. Using linear induction motors, you could launch from the Moon without even using rockets.

Remember, the astronomical cost of space is almost all used in getting there. The return trip is as easy as dropping a rock off a cliff. Once it's set up, the rest is easy. Setting it up is very hard (read astronomically expensive), the fist time. But only the first time.

My wife doesn't want more than a basic phone. she would like voice, text messaging, contact list, camera and nothing else. She is using an old Moto Razer right now, and it has too many features. A dumb brick phone would be her favorite real soon.

Meego? Nokia had Maemo working two years ago. It worked well, as anyone with an old N700 or N800 tablet could tell you. Just add a phone chip and the same software that the other phones have and there you are. But no, they couldn't go with a product that worked. Now, it all depends on Microsoft. If Microsoft fails like they have before, then Nokia is doomed. If Microsoft succeeds, then both Apple and Google/Android Foundation will up the ante. Microsoft doesn't have a very good track record at continual upgrading the software OS. So, I still come up with a net loser for Nokia.

Java/QT for developers would have been the way to go. Why didn't they just finish what they started? Corporate politics most likely. Now both the Symbian and the Linux sides lose. For a little while anyway.

HTML5, while limited, will run on every browser. It is being pitched as a platform for writing 'apps' for all of these devices. While the application sets are limited, they will work across all of the devices. Maybe we should all be brushing up on our Javascript skills.

Loosing QT for the phones is a problem, as it can be installed on all of the major platforms (unless Apple bans it), so Nokia clearly made a blunder there. I am sure though that if dropped by Nokia, the KDE folks will continue on with a QT fork. They may need a new name though. I'd suggest "graphical++". But I'm lousy with catchy names.

In China, they stock the paddies with fish when the rice is transplanted. They harvest the fish before the rice. Some of the methane you talk about is from the fish. Some is from bacteria. Bacteria are eaten by insects in the water, which are eaten by the fish, which are eaten by the people who also eat the rice. The fish also fertilize the fields. The bacteria and insects recycle human waste too. It's really an intricate system.

If you eliminate the rice, you lose the fish too. What are you going to replace that protein with? Cows or goats? they make even more methane. They would also need additional land for fodder.

  They use the system they do because it provides the most nutrition for the least land.

Of course, you need lots of water to make it work.

A magnetic sail is possible, but to do what you propose would require an accelerating field. That would mean a lot of energy.

The proposed solutions I have seen involve either a superconducting magnet to create a miniature Van Allen belt around the craft, or a static generator to place a high positive charge on the spacecraft, usually with a negative charge on a wire from the craft to balance the charge. Protons and cosmic ray nuclei are repelled by the positive charge, as they also have a positive charge. How high the charge would need to be is a function of the energy of the incoming particles.

A magnetic field would cause the charged particles to bend, hopefully missing the spacecraft. Such magnetic lenses will have directions that offer more shielding than other directions. There would be close to no shielding from directly to the poles. But, it is much easier to shield a small hole than the entire craft.

There would also be a passive shield for reducing X-ray and UV rays. Gamma rays are much harder to shield against, but since most of those pass right through you, they are actually less of a threat. Most estimates I have seen say that the passive shielding would need to be around 18 inches of water (just less than half a meter). Though any material with a high percentage of hydrogen would work. Plastics are one possibility. Foam might work too. There has also been some work on exotic materials that provide a sort of quantum barrier to some forms of radiation.

The final design of an interplanetary craft will probably use all of these, as well as some that we don't know yet.

NASA has been quietly working on all this at a fairly low level for several decades now. They aren't done yet.

Some would, that would cool the remaining water down to freezing. further cooling by sublimation would cool it to the point where it would be stable in space, like the water in a comet.

Without knowing how you would build a nuclear powered rocket, there is no way to know how much radioactive fallout would be generated.

The NERVA system would have lost around a half pound of uranium mixed with 5% plutonium on a single launch. spread out over the hemisphere, it isn't really much. Since the Uranium is naturally occurring anyway, there is always some uranium dust in the air anyway.

The Orion system, on the other hand would have left several tons of plutonium in the atmosphere after each launch.

The HTGR versions I have seen proposed would have left several hundred pounds of uranium or plutonium in the air after each launch. None have actually been built and tested, so we don't know if it would really work. For these, the exhaust is much more toxic than just the radioactive component. YMMV.

Some of the proposed heat exchange engines might have left no residual heavy nuclei behind, but they haven't been built, so it's all still theory there.

BTW, in space, if you ever point your rocket away from the Earth, you are spraying the Earth with whatever you use for thrust.

Just something to think about.

Actually, it does both, at the same time!

You lose some water to evaporation, until the ice forms and blocks the hole. After that, you lose some to sublimation, until it passes the lower temperature limit for that process (around -60 degrees C.). The the losses stop. That's why comets can form and keep intact in the outer solar system.

To work well in a spacecraft, you would want to have a high reflectance outer surface. Letting the water freeze before any hole formed would also help limit water losses, but might hinder the stop leak effect.

Correct, or almost so. The NERVA rocket did produce thrust, but leaked . The leaks were due to erosion of the pipes at supersonic flow. The system worked by injecting a working fluid (liquid Hydrogen, liquid Helium, or liquid water.) into pipes (nozzles really) that ran through a working reactor. The reactor was designed to be very high temperature. The working fluid was heated to around 2000 degrees C before emerging from the rear of the engine. The system did work, but the thrust levels were not high enough to lift a working ship off the ground vertically. The plan at the time was to build an aircraft like vessel, and fly to high altitude, then keep going faster until you were in orbit. It might even have worked.

The Nuclear Test Ban Treaty killed it. The working engine put out small amounts of the radioactive fuel. The exhaust was radioactive, not because the water or hydrogen was radioactive, but because there were small amounts of heavy nuclei in the stream. The same problem in the Japanese reactor that the US press loves to pummel. The steam itself isn't radioactive, but it carries some radioactive dust. If the Test Ban Treaty had been worded differently, work could have continued on better nozzles. Oh well.

BTW, the unit looked cool on it's test bed. For all I know, it may still be there in Nevada. Of course, it had the nuclear fuel removed in the 1970's.