InigoMontoya

Hydrogen is a very light gas. If you want reasonable energy densities, that means it must be stored under high pressures. High pressures mean heavy pumps and pressure vessels. If you want it light weight... OK, but now you either have negligible energy storage or 90% of your boat is hydrogen storage. Neither of those are desirable options. Does any such technology exist? A solar cell that is robust enough to be whipped in the wind and such like sails are? If such technology exists, I've certainly never heard of it or anything like it. They certainly could, but baring the invention of your tough-as-nails-flexible-solar-cells-used-as-sails gizmos, there wouldn't be much point. No, it doesn't. That boats can travel faster than the wind pushing them has always been one of the true marvels of sailing, IMO. Sure, but now imagine that system in a storm. I see two interesting possibilities... 1) It'll get shredded. 2) It'll destabilize the boat causing the boat to capsize. I highly doubt it.

Have you ever *watched* a shuttle launch? Almost immediately they *do* lay that sucker over and start going for speed.... Just as soon as they're out of that pea soup we call the lower atmosphere.

1 - Going 6,000 mph through sea level air doesn't require a bird strike... Just the air itself is going to hit you like a farking brick wall and turn your spaceship into a puddle of molten metal. UNLESS... You have heat shielding that is insanely thick and heavy. But now all your payload has turned into heat shield. Remind me again what the point of this was? 2 - The logistics of maintaining a loooooooong track that can handle heavy objects moving at 6,000 mph are not to be ignored. 3 - That ski jump at the end. Just how many Gs did you plan on pulling? 'Cause if it's anything other than an insane amount, you're going to lose all those benefits of a horizontal launch by bleeding energy in that thick atmosphere. And if it is an insane number of Gs, well now you're vehicle needs to be even heavier since you have extreme Gs in a non-axial direction. 4 - Yeah, bird strikes would suck. Even neglecting the costs... Have you ever tried docking a space ship to a spinning hub? How do you add a single "spoke" (aka, space ship) without throwing the whole thing off balance? And if the thing is off balance, how in the hell do you dock to begin with? It *sounds* like a good idea but the realities of actually assembling such a beast are miles more difficult than the realities of the ISS... And remember that just docking with the ISS isn't seen as a trivial task. Doable? Sure, but not trivial.

Money.

Because a lot of losses are going to be due to navigation system screw ups. If the nav system screwed up, kinda by definition the birdy isn't where you thought it was....

DH already pointed it out, but I think this bit of common mythology needs bludgeoning every time it raises it's head. SPACE EXPLORATION WILL NEVER HELP REDUCE GLOBAL POPULATION. NEVER. As was stated, you need to move 75 *million* people a year just to keep up. Even if Mars was a veritable Garden of Eden (which it obviously is not) you just couldn't do it. Right now the cost of lifting a pound to escape velocity is something like $4,000. Let's suppose somebody just goes crazy and finds a way to reduce that cost by a factor of 20. Cost to escape velocity is now $200 per pound. Wow, that's pretty damned good! Average person weighs 150 pounds? Hey, you can get a ticket for $30,000. But don't forget, it takes 6 months to get to Mars. How much food do you need to eat? I'll assume you're recycling the water, but you still need to bring on board 6 months worth of dehydrated food. I'll be nice and call that another 150 pounds. Ooops, we're up to $60,000 a seat.... And that assumes you leave *everything* behind and that somehow you'll be living in space and entering Mar's atmosphere naked (I've included no allowance for your actual space ship!). Sure, some people could and would pay it out of pocket, but the numbers for that are small indeed. It would have to be a government-funded program for the most part. Now, assuming that each country is supposed to send a proportionate number of people per year, that means the US would have to send on the order of 3 *million* people a year. At a cost of $60,000 *each*. Total cost just for the US portion? $180 BILLION. Per year! On top of everything else. Just to tread water for global population. And even if the US can afford it.... What about all those parts of the world that couldn't? And remember, those numbers are fantastically optimistic. The reality would be much, much worse. You'd probably need more like 5,000 pounds of lift capability per person (not 300 pounds) and let's not forget that the factor of 20 improvement is completely unrealistic. Actually, there's nothing draconian about it. I've applauded China's efforts for years. There are only four *realistic* options for controlling population: 1) Birth control (either voluntary or forced). 2) Disease. 3) Famine. 4) War. With options like that, even forced birth control is pretty benign.

Alternatively, I've often thought about putting a wind spire or five on a boat in place of sails. You could then use the output to drive an electric motor or charge a battery or whatever. I'm sure the propulsive efficiency would be lower than for sails, but you could also go directly into the wind. The ability to go directly into the wind *might* make up for the loss of efficiency as you could set your desired course directly rather than have to tack. Also, navigation would be much easier and the need for seamanship skills would be reduced. No worries about charging batteries though. You could definitely do that!

It's not just DH... I'm on his team. All that other stuff - with the possible exception of fission (which is politically unviable) - ARE crackpot ideas. I believe I stated as such. I believe we both stated that NASA and other agencies DO fund crackpot ideas for the unlikely direct payoff or more likely spin-off technology. Or he's an Aerospace Engineer who tries to stay grounded in reality and doesn't let his imagination taint his analysis of the situation. Also, some of us *do* represent government agencies as our day job. That means lobbying would be illegal. Actually, that's a great point regarding crackpot ideas. Spain funded Columbus at a very low level. They gave him three old, beat to shite ships that were most likely not going to be around too much longer. They gave him spare parts that were destined for the trash... Just like the laser propulsion guy in the video posted earlier. He's got an old laser from the SDI program; spare parts that were destined for the trash. Two crackpot ideas funded at a very low level. One had an enormous payoff. The other not so much (at least, not yet). Could the current guy get the last laugh? Absolutely, and that's why crackpots still get funded. As a propulsion geek I hope he does.... But I'd have to be offered some massive odds to bet on him.

But are these PLCs useful for the automation of processed ham production?

Laser/microwave: They're just a means to transfer energy; that does NOT make them in and of themselves propulsion systems. The laser that you're touting in this thread isn't really a propulsion system. What *IS* a propulsion system is superheated air. The laser just happens to be how they're powering it. But regardless of how you're powering it and how wonderful that power source may be, you still need reaction mass and these concepts have not even begun to realistically address the question of how/where your reaction mass is coming from. Space elevator: Even if tomorrow somebody came up with the wonder fiber that would make the space elevator possible there are other issues. Most notably (IMHO), the proponents of the space elevator forget one of the most fundamental realities... Center of gravity. To get a space elevator to "stand" it's center of gravity must be at a very high orbit. What is it, like 36,000 miles? Which means that to get the center of gravity that high you must have HUGE mass at that same height (slightly above it actually, but who's counting?). Where is this mass going to come from? You can't use the elevator itself to raise it. You have to get it up there. So... Imagine turning to Congress and saying, "Yes, sir. We need to launch approximately 5,000 Saturn V rockets to get a large enough counter weight up to orbit to stabilize the elevator... But after the elevator is in place getting to space will be cheap!" Do you see the problem there? Again, you are oblivious to what's going on TODAY. SpaceX (on a NASA contract) has already flown the first prototype of a manned capsule that will ultimately provide the US with it's manned capability. No, it won't have the same capabilities as the Shuttle but it will be MUCH more cost effective to fly. Will it be ready to go by the time the Shuttle retires? No, but it won't be far off either. Seriously, all the "sky is falling" talk about NASA not having a replacement for the Shuttle is ill informed at best and alarmist at worst. Again, the replacement *has already flown*. True, it was just an unmanned test flight, but the point is that it is well beyond a paper study. It's real. It's happening. And it will be operational in a couple years. Don't take my word for it... READ.

Fission could work but the politics of it are insane. Laser, space elevator, and microwave? That's EXACTLY what I'm saying. They won't bring the cost down and they will not work. At least, not in our lifetimes. Not even close. Because it captures the imagination of the public (see: public relations) and there are other applications to any advances in laser technology (so even if it doesn't work, there are still benefits).

What he said, Nec209. I can't speak for NASA, but as one who makes his living testing rocket motors for the DoD, I assure you that our government DOES fund crackpot ideas at a low level for precisely the reason stated above. The odds of a payoff are low, but they're willing to fun low-level efforts on the off chance that one of them works. DH mentions the "Breakthrough Propulsion Physics Project." On my side of the fence, the efforts would have been under the IHPRPT program (IHPRPT did more than just crackpot ideas, but there were certainly crackpot ideas under IHPRPT.). The government funds crackpot ideas if they're cheap. That is an absolute fact. So how expensive is our "laser heated air in space" concept? Well, let's see.... It's primary piece of equipment is a laser that's left over from the SDI program. Cost? Free. Another hint: Their test set up is primarily outdoors despite the fact that a very cheap building could give them a much safer laser environment, eliminates wind affects and protects their set up from the elements when they aren't testing. Implication? There's no funding for even a simple metal building. In other words.... His funding levels absolutely indicate that nobody at NASA is taking him seriously. He is a crackpot but they keep him around for the PR value. And heck, not only are you oblivious to a realistic science future, you're oblivious to current science. SSTO? It's been possible for 40 years. It's called the booster for the Atlas rocket. It is SSTO capable... Of course, there isn't much point in sending a booster to orbit with no significant payload and it's not reusable, but that's not the point. Also, pay attention to SpaceX. I think you'll find that they're making huge dents in the cost of space travel but nobody is even mentioning the name Elon Musk and Nobel Prize in the same sentence (this sentence aside, of course).

Dunno how recent that video is, but everything in the first five minutes could have been said 10 years ago. At least, that's when I became aware of it. I don't know what if anything has changed, but at the time nobody took it too seriously. It was seen as a sort of "Let's hope this guy can do something with these cool lasers we spent all that money to develop for a program that just got canceled." IE, they were hoping to find a silver lining. That was 10 years ago. If that video is current, it doesn't look like he's made ANY progress (He was doing those sort of short flights in the late 90s!). As for the microwave comments, I'll spell it out for you... Rather than focus a tight beam of light energy (ie, a laser) that if you aim poorly it will set forests on fire or whatever, we'll use a very wide, but much less intense beam of microwave energy. That way, if we aim poorly the consequences are less dire. In addition, microwaves are much less sensitive to atmospheric conditions so aiming the beam should be much easier. Beyond that, however, the second half of the video strikes me as a complete ball of crap intended not for serious science, but rather entertainment value. Really, they want to use the energy to create an aerospike? Why? That's a $10,000,000 answer to a $10,000 problem. Aerospikes are already out there and in use particularly on Russian-designed manpads and the US Trident system. Except that the aerospikes in use are mechanical rather than formed via gas manipulation via energy beams. And they didn't address the problem of "where is this air that you're going to superheat at high altitude?" They just show their little spaceship blazing through LEO (flying by their satellite) with no serious discussion of reaction mass. They hinted at Helium, but Helium is very expensive now and getting nothing but more expensive every year (a problem that would be compounded by a space launch system that required large quantities of it). Even if the new system were to use He at 6X the efficiency as conventional systems, it's likely to be more expensive even if you only need 1/6 as much. Not much point in that.

Google for "ICF" (Insulated Concrete Form) construction. Basically you build a structure out of hollow styrofoam blocks that you glue together. Need a window? Just cut a hole in the styrofoam! When your structure is complete, you pump concrete into the void (remember, the blocks are hollow). When the concrete cures, it provides a very sturdy/durable structure while the foam blocks provide insulation. Obviously there's a bit more to it, but that's the basic concept. Materials are more expensive than traditional methods, but there are a lot of savings on the labor side of the fence and the final result is superior.

Hard to say even assuming flight computer would allow it (or could be over-ridden). Limiting factors are likely to be structural. But it is worth noting that a .

Are you serious? Space = no air. Where is this air that you're going to heat up coming from? A system like you mention may work great a low altitudes, but once the air starts getting thin it's effectiveness is going to suffer drastically due to lack of sufficient reaction mass - i.e. air. And this is going to start happening loooong before you get to space. Space is generally accepted to be on the order of 100 miles. At 20,000 feet - less than 4 miles - your air density is already half of what it started as. At 40,000 feet - we'll be nice and call it 8 miles - you're dealing with 25% and you've still got 92 miles to go. Further, once you're supersonic you're going to have even lower density than ambient air surrounding the base of your vehicle courtesy of expansion shocks. Admittedly, air breathing aircraft prove that you can use air as a reaction mass up to 80,000 feet... But they convert their thrust to lift much more efficiently than your rocket is going to (wings are great for this) and they're still what - 84 MILES short of the goal. In summary: It's awful tough to use a laser to heat up the air when there is no air.

You mean maybe something like THIS? Ditto (including the "I'm an engineer" part).

1. I'm not aware of ANY heaters in the industrialized world that mixes heat and humidity. 2) OK, but... Why? It's not like you're coming into contact with either the water or the glycerin in any way shape or form. Nor are they toxic so there are no end-of-service-life clean up issues. 3) Spectrum is controllable via temperature, no? 4) So go find whatever heating system it was that gave you this preference and install it. Or move to Chile.

An old-school radiator filled with glycerin instead of water (what do you have against water, anyway?) that is heated with a solar array during the day and stored in an insulated reservoir for night time use.

A more recent photo....

[Meh, nevermind]

Well, millions of dollars are being spent on that very problem every year. And yet, they're nowhere close. So, you ask "How difficult would it be?" And the answer so far appears to be, "Extremely."

You absolutely could convert a diesel engine to run off steam. It really wouldn't even be THAT difficult to do given the right resources and a desire to do odd things just because you can... 1) Build a boiler/firebox/etc. 2) Replace the carb/intake system on the diesel with a simple high pressure intake that delivers dry steam from the boiler to the cylinder heads on the diesel. 3) Replace the cam shafts on the diesel to alter valve time such that you're no longer running a 4-cycle diesel cycle and are now running a 2-cycle steam cycle. As for using the steam engine to drive a turbine to generate electricity.... Why? Just go get a turbine and drive it directly with steam.

Nah... His language skills are perfectly acceptable for a job in the Custodial Arts.

Yup. And we've been doing it for the past 50 years. They're called "staged rockets." Assuming the above means you want to attach a cable to the surface and let the Moon take you for a little ride with it's rotational energy.... First off, the Moon spins very slowly. The speed at the surface of the Moon due to it's rotation (What I believe you're refering to as "x number kph") isn't really that much. Let's work it out, shall we (math included in case I screw up)? Velocity = RadiusOfMoon * Theta where: Theta = angular velocity of the Moon in radians per second. Theta = (1 rotation / 28 days) * (1 day / 24 hours) * (1 hour / 3600 sec) * (360 deg / 1 rot) * (pi rad / 180 deg) = 2.597e-6 rad/sec RadMoon = 1737 km = 1737000 m/s Therefore... Velocity = 1737000 * 2.597e-6 = 4.51 m/s = 16 kph. Wow... Yeah, you're really screaming there.