I live in a country where we used to burn Jews and neo-Catholics during the so called Renaissance, my parents are Catholic, I am Catholic. So is the vast majority of the population.
Yes. There is nothing wrong with scramjets. The fast response capability would be very useful for several military tasks, like the ones I pointed. I just get annoyed by seeing the promotion of airbreathing scramjets for orbital launch like it is going to be so much better than rockets, when it is no replacement for rockets at that particular task. Spending money on scramjets thinking it will help space launch somehow is nonsense. For that, what we need are better rocket engines and more energy dense, high ISP fuels.
NASA spends money on a lot of things which are completely useless for space launch. Like the X-29A.
I have seen such designs for space launch vehicles using scramjets. They are not a new idea. Ever heard of Saenger II, Tu-2000? Here is a more complete list of these colossally expensive failures.
All the designs using scramjets rely on tricks to achieve orbital capability. Rocket-powered sleds for launch, rockets for reaching orbital velocity, etc. Why not use a regular rocket in the first place? At least the spacecraft would have less points of failure and would likely have less weight.
FYI, orbital velocity is Mach 26, not Mach 10. The amount of kinetic energy required increases quadratically with the target velocity: E = 1/2*m*v^2. Perhaps now you see why space launch is tricky.
There is this tendency to say scramjet powered vehicles are space planes, but the truth is they are very poor space vehicles. Why?
Because something travelling at Mach 5 max will never reach escape velocity. So this thing is suborbital at best.
Not to mention scramjets only work from Mach 2 or thereabouts, so you need an alternative engine to speed the plane up to Mach 2, then you use the scramjet to go up to Mach 5. Plus there is the additional problem that liquid hydrogen is low density, cryogenic fuel.
The main use for such technology is a high-speed intercontinental bomber or reconnaissance platform. Not space launch. So far no other engine beats rockets for cost/efficiency when doing space launches.
Right. The low half-life nuclear elements like strontium and caesium have been used for batteries since the 60s at least. The Voyager and Cassini space probes used these so called RTG batteries. So did several Soviet spy satellites (including one which crashed over Canada). The Soviets also used it to power electronics equipment, like radios and seismography machines in the far reaches of the Arctic.
However it is still mainly used for military applications because of the risk that someone made a dirty bomb with it. If this risk is hyped or not I dunno, but that is the reason usually pointed.
I was talking about the power grid. For automobiles, hydrogen fuel cells output no CO2. Only problems are that hydrogen tanks are heavy, hydrogen has a low density and the fuel cells are expensive so far. Given mass-production of fuel cells and the use of borax or lithium hydrides, those problems would be solved. Flywheels also could possibly work in limited cases. The military is considering using them for their all electric tanks. In short: the problem with electric cars is energy storage. The engines themselves have never been a problem.
Man made hydrocarbon fuels are an interesting concept for when oil runs out, but AFAIK none of the current alternatives produces a net positive energy gain, let alone be cost competitive with oil, coal or nuclear.
IMHO we should move away from hydrocarbons anyway. They usually produce carbon monoxide and ozone due to unclean burns which cause all sorts of health problems for people with asthma, etc. We should have pushed the smog away from our cities long ago, not make it even worse.
As a matter of a fact, a terrorist act against a nuclear power plant would have quite limited effects compared to other targets.
Like for example, poisoning the state water supply. Also, do not think other energy sources are invulnerable to terrorist acts. Ever saw a gigantic flaming ball of gas? Or what about a huge Exxon Valdez like oil spill near a populated area? Or an ammonia factory explosion, etc. Just face it, any concentrated form of energy is potentially dangerous if not adequately controlled.
Biomass burning emits carbon dioxide. Hence promoting global warming. Same thing for burning alcohol and, I suppose, biodiesel as well.
If you are interested in burning carbohydrates you are better off burning oil, at least it is cheaper.
Past experience with energy crops has been dysmal. Examples: sugar cane and corn alcohol. The US government spent quite a lot of money subsidizing corn alcohol for fuel to find out it actually produced a net energy loss when you consider you have to use agricultural machinery. Perhaps you intend to use manual labour instead? Good luck going medieval.
Nuclear power is a much better proposition but you probably have an irrational fear of it.
Regarding NERVA, yes, that is a good question. The Russians worked on Nuclear Thermal rockets using Ammonia as the ejection mass and it didn't have much more ISP than LOX/LH2. So much for that idea.
If you use LH2 you do need those lousy bulky tanks. I suppose one could use something else for the ejection mass that isn't quite as troublesome. I wonder if plain old Water (H2O) would be better than the nasty Ammonia (NH3). You could always compensate the inneficiency by making the reactor core even hotter. But there goes safety... Gaseous Fission rockets exploit this angle.
There are other choices like the lovely Nuclear Photonic rockets, but I doubt they would have enough thrust to make it worthwhile for first stages.
If you don't believe me, just read any of his articles.
This CPU is a good deal, Athlon 64 at Athlon XP prices. Some of us actually need to buy machines now, not in the next 6 months. Oh, wait to find a socket 939 processor at $200 like that jackass Ed is saying. With luck, it will only take until Xmas next year.
I think Carmack said that last month as well... I wish him luck, but considering he is an amateur and we wants to use a bleeding edge peroxide monoprop engine, his chances aren't very good of the engine working to meet prize requirements.
So rockets have astronomical development costs and you want scramjets instead because they are cheaper to develop? Good luck. The military has been dumping billions on scramjets for decades now, you can see the results for yourself.
Who cares about nuclear reactors issues in space? They are pretty safe down here, up there, the radiation is too small to make a difference, even if it did meltdown.
They provide power for long-range, outer planet missions, something that solar panels cannot do decently. So just use them.
China already has nuclear technology, most of the concern today is with proliferation of the know how to make nuclear weapons to unfriendly states.
The argument regarding Iran is that it is highly suspicious for a country with vast oil reserves like them to devote resources in nuclear energy. It is likely they are using that program as smoke and mirrors to cloak an effort to develop nuclear weapons.
Is GPS guidance precise enough for you? The US Military seems to be ok with it. Granted, they use the military version of GPS, not civilian, but it is still pretty good compared to what most V1s used.:-)
The V1 buzzbomb was the first cruise missile. The definition of cruise missile has nothing to do with navigational skills. You could still aim it at your target and IIRC some versions used a relatively sofisticated method of target determination, that the British figured out how to jam eventually...
They had SAMs. Ever heard of Wasserfall? The thing is, Hitler always pushed offensive weaponry over defensive weaponry. The budget was low and only because the other people in Hitler's government pushed him to do something about Allied bombing.
Besides, the Allies led the field of Radar and Sonar. SAMs require good Radar systems in order to be effective.
Sure, but when playing total war like WW2 was, resources are very, very important. While a barrage of missiles could prove useful to intimidate certain targets into submission, it was the massive carpet bombing campaigns that really hurt. More terminal effect for the same money.
Of course you need control of the airspace in order to conduct these sorts of massive bombing campaigns and yes, radar and AA made it more difficult. But then again, SAMs weren't so much of a problem back then as they are now.
Just compare the terminal effect of Allied bombing vs the effect of Axis missile attacks for e.g.
Sure, I am talking about USA foreign debt, the total debt is a different thing.
Regarding playing space race instead of paying up to IMF, it isn't like the USA spends less money on defense and space to pay their foreign debt either is it? FYI the USA spends more money on defense than the rest of the world combined and the USA spends more money on space than the rest of the world combined.
The interesting thing is that, as the Russians plug the holes in their nuke shield, the USA dismisses its equivalent deterrent. The Peacekeeper. This is a large MIRV missile which was forbidden under later treaties. But ever since the USA stepped down from the ABM treaty, Russia has threatened to develop MIRV versions of Topol-M. Hence the USA is dismissing its most recent deterrent. Which by the way, is less survivable than Topol-M since it is only silo-based. The railroad version was never put into use AFAIK. Topol-M is silo, railroad and road based. It has more survivability because the bases are mobile.
Topol-M also features a maneuverable warhead to evade anti-missile systems by presenting a non-ballistic terminal trajectory.
The Russians also have better anti-missile systems in the shape of the S-400 Triumf. Some of their anti-missile systems can also be fitted with tactical nuclear warheads to ensure a better kill ratio.
This means the USA's nuclear deterrent now mostly consists of the submarine launched nukes (i.e. Trident).
Slashdot Mirror
I do not know one single circumcised person.
Catholics aren't circumsized. Jews are.
LISP is a nice language, except for the numerous ()'s. I know you can supposedly get used to them, but I never got used to it.
Remember all the noise the Greens made when Cassini was launched?
Yes. There is nothing wrong with scramjets. The fast response capability would be very useful for several military tasks, like the ones I pointed. I just get annoyed by seeing the promotion of airbreathing scramjets for orbital launch like it is going to be so much better than rockets, when it is no replacement for rockets at that particular task. Spending money on scramjets thinking it will help space launch somehow is nonsense. For that, what we need are better rocket engines and more energy dense, high ISP fuels.
I have seen such designs for space launch vehicles using scramjets. They are not a new idea. Ever heard of Saenger II, Tu-2000? Here is a more complete list of these colossally expensive failures.
All the designs using scramjets rely on tricks to achieve orbital capability. Rocket-powered sleds for launch, rockets for reaching orbital velocity, etc. Why not use a regular rocket in the first place? At least the spacecraft would have less points of failure and would likely have less weight.
FYI, orbital velocity is Mach 26, not Mach 10. The amount of kinetic energy required increases quadratically with the target velocity: E = 1/2*m*v^2. Perhaps now you see why space launch is tricky.
Because something travelling at Mach 5 max will never reach escape velocity. So this thing is suborbital at best.
Not to mention scramjets only work from Mach 2 or thereabouts, so you need an alternative engine to speed the plane up to Mach 2, then you use the scramjet to go up to Mach 5. Plus there is the additional problem that liquid hydrogen is low density, cryogenic fuel.
The main use for such technology is a high-speed intercontinental bomber or reconnaissance platform. Not space launch. So far no other engine beats rockets for cost/efficiency when doing space launches.
However it is still mainly used for military applications because of the risk that someone made a dirty bomb with it. If this risk is hyped or not I dunno, but that is the reason usually pointed.
Man made hydrocarbon fuels are an interesting concept for when oil runs out, but AFAIK none of the current alternatives produces a net positive energy gain, let alone be cost competitive with oil, coal or nuclear.
IMHO we should move away from hydrocarbons anyway. They usually produce carbon monoxide and ozone due to unclean burns which cause all sorts of health problems for people with asthma, etc. We should have pushed the smog away from our cities long ago, not make it even worse.
Like for example, poisoning the state water supply. Also, do not think other energy sources are invulnerable to terrorist acts. Ever saw a gigantic flaming ball of gas? Or what about a huge Exxon Valdez like oil spill near a populated area? Or an ammonia factory explosion, etc. Just face it, any concentrated form of energy is potentially dangerous if not adequately controlled.
If you are interested in burning carbohydrates you are better off burning oil, at least it is cheaper.
Past experience with energy crops has been dysmal. Examples: sugar cane and corn alcohol. The US government spent quite a lot of money subsidizing corn alcohol for fuel to find out it actually produced a net energy loss when you consider you have to use agricultural machinery. Perhaps you intend to use manual labour instead? Good luck going medieval.
Nuclear power is a much better proposition but you probably have an irrational fear of it.
If you use LH2 you do need those lousy bulky tanks. I suppose one could use something else for the ejection mass that isn't quite as troublesome. I wonder if plain old Water (H2O) would be better than the nasty Ammonia (NH3). You could always compensate the inneficiency by making the reactor core even hotter. But there goes safety... Gaseous Fission rockets exploit this angle.
There are other choices like the lovely Nuclear Photonic rockets, but I doubt they would have enough thrust to make it worthwhile for first stages.
This CPU is a good deal, Athlon 64 at Athlon XP prices. Some of us actually need to buy machines now, not in the next 6 months. Oh, wait to find a socket 939 processor at $200 like that jackass Ed is saying. With luck, it will only take until Xmas next year.
They can still copy the Flash files as well. Makes no bloody difference, expect they are using non W3C standards. Bad, very bad.
See this.
I think Carmack said that last month as well... I wish him luck, but considering he is an amateur and we wants to use a bleeding edge peroxide monoprop engine, his chances aren't very good of the engine working to meet prize requirements.
So rockets have astronomical development costs and you want scramjets instead because they are cheaper to develop? Good luck. The military has been dumping billions on scramjets for decades now, you can see the results for yourself.
Why would anyone choose it over Linux of FreeBSD is over me.
They provide power for long-range, outer planet missions, something that solar panels cannot do decently. So just use them.
China already has nuclear technology, most of the concern today is with proliferation of the know how to make nuclear weapons to unfriendly states.
The argument regarding Iran is that it is highly suspicious for a country with vast oil reserves like them to devote resources in nuclear energy. It is likely they are using that program as smoke and mirrors to cloak an effort to develop nuclear weapons.
Is GPS guidance precise enough for you? The US Military seems to be ok with it. Granted, they use the military version of GPS, not civilian, but it is still pretty good compared to what most V1s used. :-)
The V1 buzzbomb was the first cruise missile. The definition of cruise missile has nothing to do with navigational skills. You could still aim it at your target and IIRC some versions used a relatively sofisticated method of target determination, that the British figured out how to jam eventually...
Besides, the Allies led the field of Radar and Sonar. SAMs require good Radar systems in order to be effective.
Of course you need control of the airspace in order to conduct these sorts of massive bombing campaigns and yes, radar and AA made it more difficult. But then again, SAMs weren't so much of a problem back then as they are now.
Just compare the terminal effect of Allied bombing vs the effect of Axis missile attacks for e.g.
Regarding playing space race instead of paying up to IMF, it isn't like the USA spends less money on defense and space to pay their foreign debt either is it? FYI the USA spends more money on defense than the rest of the world combined and the USA spends more money on space than the rest of the world combined.
The interesting thing is that, as the Russians plug the holes in their nuke shield, the USA dismisses its equivalent deterrent. The Peacekeeper. This is a large MIRV missile which was forbidden under later treaties. But ever since the USA stepped down from the ABM treaty, Russia has threatened to develop MIRV versions of Topol-M. Hence the USA is dismissing its most recent deterrent. Which by the way, is less survivable than Topol-M since it is only silo-based. The railroad version was never put into use AFAIK. Topol-M is silo, railroad and road based. It has more survivability because the bases are mobile.
Topol-M also features a maneuverable warhead to evade anti-missile systems by presenting a non-ballistic terminal trajectory.
The Russians also have better anti-missile systems in the shape of the S-400 Triumf. Some of their anti-missile systems can also be fitted with tactical nuclear warheads to ensure a better kill ratio.
This means the USA's nuclear deterrent now mostly consists of the submarine launched nukes (i.e. Trident).