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Post by ka9q on Jul 27, 2010 17:45:02 GMT -4
There's no $$ in being a "proagandist". To hear the CTs tell it, we're all being handsomely paid by NASA to patrol the interwebs and rebut anything that contradicts the Official NASA Line. They certainly think of themselves as important and worthy of such official attention, don't they? They seem unable to believe that we're just ordinary individuals with a personal interest in the space program. We're profoundly offended by all the utter nonsense about an Apollo "hoax" and concerned about what it's doing to public discourse and understanding of science and technology in general. Yes, some of us are scientists, engineers or technicians, though only some actually work in the aerospace industry, and fewer still (any?) are on the NASA payroll. The CTs act as if such technical backgrounds should disqualify us when they actually mean we're more likely to know what we're talking about. This attitude says far more about the CTs than anyone else.
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Post by ka9q on Jul 27, 2010 17:28:59 GMT -4
Right now he's probably at a point where he realizes that he's always been wrong but he's dug himself so far into a hole, there's no way out of it without admitting to the world what an complete fool he has been. This is an extremely common phenomenon, and it's not limited to conspiracy theories. Bob Park, a physics prof at the University of Maryland who writes a regular skeptical column called What's New, wrote a fun book titled Voodoo Science: The Road From Foolishness to Fraud about fraud and crackpottery in science and inventing. He points out that it's an extremely common pattern for a crackpot to start by sincerely believing that he's found something new, such as a "free energy" device. This is usually the result of an inadequate educational background, e.g., not understanding basic principles like the laws of thermodynamics. The individual goes public and/or accrues a group of financial backers that thrust him from obscurity into a position of wealth and admiration he never thought he'd find himself in. He's hooked. But eventually he realizes, as he tries to actually make his device work, that he was wrong - his device cannot ever work. By this point he has most likely already crossed the line - he has faked his first demo. He may have rationalized it by telling himself that it's just to keep his investors off his back for a little while until he gets it working for real. But of course he never does, because it violates some basic physical principle like the conservation of energy. So on it goes. The lie gets bigger and bigger, and with it the excuses. Some would-be inventors can keep the scam going for many years, with multiple rounds of investors.
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Post by ka9q on Jul 27, 2010 11:55:02 GMT -4
The volume of the Apollo astronauts voices didn't change no matter how far they were from the camera so it was obviously all a hoax Good one!
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Post by ka9q on Jul 27, 2010 8:14:55 GMT -4
An even better question, I think, is how a video on the topic of the audio level in someone else's video is even conceivably relevant to the "question" of a supposed Apollo hoax. I mean, isn't this getting pretty far off on a tangent?
All the better to avoid having to defend some pretty outrageous claims, I think.
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Post by ka9q on Jul 27, 2010 8:12:26 GMT -4
I'd love to see a return to the Apollo 15 site Apollo 15 is my favorite lunar mission simply because of that spectacular canyon. In my opinion, public support for space is almost entirely about pretty pictures. Imagine going back to Hadley Rille with modern digital cameras.
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Post by ka9q on Jul 26, 2010 23:55:26 GMT -4
Also, the dr El Baz idea of driving the LRV via the GCTA camera to capture the next LM landing! _That_ would have made for some awe inspiring video!! Never heard that one! I seriously doubt it could have been done without an external source of power, such as a large solar array -- and how would it be made mobile? There'd be the problem of keeping the rover from freezing during the 2-week lunar night. As it was, they had serious thermal problems even while the crews were still there, during the relatively benign thermal conditions of lunar morning. The landing sites weren't all that close either, so even with the slower pace of the J-missions would they have had enough time?
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Post by ka9q on Jul 26, 2010 23:47:03 GMT -4
I simply hadn't realised how much of the Saturn V's mass was in the first stage fuel tanks. Oh yes. The purpose of that inboard shutdown is to limit acceleration to 4 g. Check out the flight report for a typical Saturn V flight. They always include a plot of longitudinal acceleration vs time. They're very characteristic, so if you've seen one they're very easy to find in the other reports. I wonder how much theoretical performance they lose by doing that. Gravity loss is always greatest early in the flight of a launcher, when the pitch angle is still high and a significant fraction of thrust is still overcoming gravity. That's why the Saturn V's acceleration is greatest during first stage flight (and why kerosene was chosen as the fuel.) The upper stages operate with a pitch angle of nearly zero, so the gravity loss is correspondingly small. Then the engines can be optimized for Isp rather than maximum thrust. The problem is that you don't always know, preflight, exactly what the fuel-oxidizer flow rates will be for those particular engines under those particular conditions. The IU can measure them in real time and adjust the time of PU shift so that the two propellants will deplete at (or close to) the same time. Also note that when the PU shift occurs and the mixture goes a little rich, the Isp of the engines increases slightly due to the decrease in average molecular weight of the exhaust. I don't know how much this contributes to performance - it may not be significant - but it's still there. You don't want to do it earlier because the PU shift also decreases thrust, and decreasing thrust before you've pitched down to the local horizontal increases gravity loss.
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Post by ka9q on Jul 26, 2010 19:06:36 GMT -4
OTOH NASA are very likely to revisit at least one of the old landing sites in order to study the how the materials were effected by long term exposure to the lunar environment. Yes, that's a perfectly good reason for going back. We don't have a very big database on the effects of long-term space exposure. Most of the objects we launch into space have burned up in the atmosphere or simply weren't designed for retrieval. Our only sample point on long term lunar exposure is Surveyor III. It spent about two and a half years on the lunar surface before being visited by the Apollo 12 astronauts, who brought back some components for study. It wasn't originally designed as a lunar environment exposure experiment, so I don't think it included many materials that we'd like to know about. We also have LDEF, which spent 5.7 years in low earth orbit, much longer than originally intended because of the Challenger disaster. But low earth orbit is a very different environment than the surface of the moon. Atomic oxygen is a major factor in LEO but insignificant on the moon. The moon, on the other hand, has far wider temperature swings because of its long day, and it spends most of its time well outside the earth's magnetosphere. I don't know of very many other space artifacts, 40 years old or older, whose locations we exactly know. And hey, anything with the side benefit of further helping to shoot down the conspiracy theorists is fine with me.
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Post by ka9q on Jul 26, 2010 17:53:39 GMT -4
Just been looking through his Tetra (?) video This is a typical Jarrah White video. He drills deep into "he said, but no, she said" arguments as a way to evade the substantive issues. His ambush of Adam Savage was along the same lines.
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Post by ka9q on Jul 24, 2010 22:33:41 GMT -4
This is a perfect example of a favorite Apollo conspiracist tactic: quote or show an "expert" who can't explain something, and assert that no explanation therefore exists.
A related tactic is to disparage a "pro Apollo" expert by showing that his or her knowledge is incomplete or incorrect in some way irrelevant to the points made by the expert.
A good current example is Jarrah White's recent ambush of Adam Savage regarding Adam's lack of knowledge of moon laser ranging experiments prior to the Apollo program.
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Post by ka9q on Jul 24, 2010 2:30:59 GMT -4
Interesting, that's actually more than I would have expected. Still, it's not enough to compensate for the moon's rotation, 360 degrees per month or about 13 degrees per day.
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Post by ka9q on Jul 23, 2010 17:30:15 GMT -4
Now there is a set of problems related to the conversion of electric power to mechanical power for transportation that include various heat engines among the proposed solutions. They include:
Conversion of solar or nuclear energy (e.g., from a reactor or radioisotope) to electrical energy;
Storing electrical energy for both stationary and vehicular applications (i.e., transportation).
The energy storage problem on the moon is especially acute when the prime source is solar, due to the 2-week long lunar night. (Personally I think there's no viable alternative to the nuclear reactor, at least for early lunar bases, but I'm willing to be proved wrong with a workable alternative design.)
There are two established methods for the conversion of solar energy into electrical energy that could be viable on the moon: thermal and photovoltaic. The latter is simply the familiar solar panel. They're well established in spacecraft and their technology steadily continues to improve. But their costs are high, especially for the most efficient models.
The alternative is a heat engine. This could work well on the moon since the lunar vacuum makes it possible to maintain a large temperature difference between the solar collector and the radiator to deep space. (Every heat engine requires both a source of heat energy and a heat sink into which waste heat can be rejected at a lower temperature than the source.)
Solar heat engines have traditionally been cheaper, per watt, than photovoltaics and many have been more efficient too. It is not clear if this trend will continue as research into photovoltaics continues to produce units with higher and higher conversion efficiencies on sunlight. And it's not clear that cost is much of an advantage for anything that has to be lifted by rocket from the earth and soft-landed by rocket on the moon; the output per unit weight seems much more important. And here the advantage again seems to go to the photovoltaic panel.
The nuclear reactor would be especially useful for the waste heat it could continuously generate through the long and cold lunar night. And because of its higher operating temperature, the heat engine it drives would probably be smaller, lighter and more efficient than a heat engine driven by sunlight. On the other hand, the lack of a solar atmosphere would allow sunlight to be concentrated many times to provide a high temperature (and therefore more efficient) heat source for the heat engine. So the relative merits between solar and nuclear, I think, have to do with nuclear's ability to operate at night while solar can operate indefinitely without fuel.
It may turn out that there's a place for both solar and nuclear generation in the lunar base. Nuclear provides a baseline of both power and heat during the night, and solar power supports additional activities during the day that do not have to run continuously. These activities could include energy-intensive operations such as the production of oxygen from the lunar regolith, or the mining of water from shadowed craters at the poles and the production of elemental hydrogen (otherwise scarce on the moon) from that water. Of course, it may be possible to establish a polar lunar base in a position that gets continuous sunlight, and such a location would be ideal for solar power generation, but I'm sure the number of such sites would be rather limited.
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Post by ka9q on Jul 23, 2010 17:14:04 GMT -4
I just discovered this thread, and I have to say that I'm baffled. I can't understand the purpose of the invention, or how it's an improvement on the state of the art.
The apparent goal is to convert electrical energy into mechanical energy to drive a vehicle. We have had the technology to do that literally for centuries: it's called the electric motor. The technology is quite mature (though there have been recent improvements thanks to high power semiconductors), highly reliable and quite efficient (95+% is common at vehicular power levels).
You want to replace this with a heat engine, for which the severe limits on conversion efficiency imposed by the second law of thermodynamics are very well known. (ref: Carnot limit)
Furthermore you want to convert the electrical power input into heat in a rather exotic way (a laser) when the standard, simple and highly effective (100% efficient) method is with a cheap, simple, passive electrical component called a resistor.
Forgive me if none of this is making any sense at all.
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Post by ka9q on Jul 23, 2010 16:57:30 GMT -4
One thing to investigate is the nature of the secular perturbations of lunar orbits. I'm sure you're quite familiar with the usual precessions of earth orbits: the slow change in RAAN (exploited in sun-synchronous orbits) and the rotation of the line of apsides (brought to zero by the 63.5 deg inclination of the Molniya and Tundra orbits). But these are due to the earth's oblateness associated with its fairly fast rotation. The moon rotates 30 times slower, so it can't have a large J2 term like the earth. But it does deviate substantially from a sphere, in part because it's so much smaller. Also because it's smaller, perturbations from the earth and sun are significant.
The Apollo mission planners may have discovered how to make a lunar orbit precess in RAAN so as to partly follow the moon's rotation and lessen the plane change required for a rendezvous with the LM.
At some point in the (distant) future, when we have multiple lunar bases and transportation systems, I'm sure a lot of thought will go into the tradeoffs between landing a mission close to a desired location (or launching it from there) and landing it at a location that's energetically favorable and then traveling across the surface to where you want to be. This will be especially relevant to the bases at the poles that are getting a lot of attention. Suppose you don't care about taking off again; how much more delta-V does it take to do a direct descent to the lunar poles from the earth than to the lunar equator?
Traveling across the lunar surface will be quite an engineering challenge in itself. I never thought the "lunar bus" depicted in "2001" would be a particularly efficient way to do it, as hovering with rockets is pretty wasteful even in a reduced gravity field. But I guess that looked a lot sexier on screen than an ALTV (All Lunar Terrain Vehicle) with big wheels...
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Post by ka9q on Jul 23, 2010 16:44:44 GMT -4
I have no doubt that the HBs would come up with a ludicrous explanation to dismiss it! Yup, no doubt you're right. They'd claim that "everybody knows" nothing can possibly change on the moon without air or water erosion, so the degradation of the Apollo materials had to have been caused by weathering right here on earth, proving they're just showing the original moon sets out in the desert in Area 51...
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