PB666

M$paint

None of my cows are religious. actually. Well they got up 2 today in one launch. Maybe next time they'll do 4 at a time. The only real problem with the last launch, we didn't get to see it blow up on the barge.

If one of the engines is underperforming, you bet. Those engines were supposed to cut down as the rocket was meters from the target, but if the rocket is in full deceleratoin as it hits the target first there is the shock wave from the landing struts and then the shockwave from the engines striking the deck. The effect on parts varies but a part supporting the engine bay could suffer over 30 g of deceleration.

Yep more. http://phys.org/news/2016-06-gravitational-pair-colliding-black-holes.html http://www.bbc.com/news/science-environment-36540254

There are other problems. You have bending forces on the bottom because a small part of the bottom of the rocket has the full force of engine thrust where as the areas of the six other engines do not. The non weight bearing surfaces of the rocket are being accelerated into the higher g-range and could fail. Its not so simple as the engines are producing no more thrust than launch and the weight is lighter, there peak forces move to different parts of the rocket, and those parts may fail. Things like fuel lines at 8G could become detached or kink, electrical couplings could short or break circuit, you can have insulation shift, all kinds of problems. There is force and there is acceleration two different metrics. Maximum force is applied to the core right at the engines and diffuses upward into the frame of the rocket, the crosssectional average moment of force declines moving up the rocket at maximum thrust. At maximum dynamic pressure, which based on their telemetry is not that great; sandwiches the middle of the rocket between thrust and drag forces applied to both ends. The forces exerted by the boundary layer that expands with speed and overpressures down the side of the rocket pulls panels and pushes panels in different places as the rocket speeds up in the the air stream. Imagine however if you were hanging by your heals in a space suit from the bottom of the RP1 tank the blood pressure in your head causing your face to turn red starts off with a maximum of about 1.8 meters x 1.2 g + static blood pressure lying down. As the rocket accelerates to a maximum of 3 g but is turning so you have about 3.3g x your incline of about so that the vertical is about 1 meters. So now you are landing on the barge at 8g of deceleration and the barge is applying another 8g forces, you are now experience 15g or so of force with 1.8 meters. You blood vessels in your brain have ruptured and you are bleeding from your nose and the vessels inside of your eyes have ruptures and filled with blood. That's what the rocket experiences in a high g-force deceleration and contact landing. This is why I say the forces of deceleration and landing create an upper limit of decelerations which cannot be surpassed without creating more structural strength.

OK, first they release the payload at 8800 km/h which is 2444.444 meters per second. To deploy droque chutes at that altitude would have to have a huge crossectional area, 100s of meters appart, as it comes into the atmosphere the bindings would have to be incredibly strong. The are traveling down to the barge just under Mach speed, Even at half or 1/3 mach the rate of air acceleration around the chute causes air to have to exceed the speed of sound, which places a 'air hammer' on the chute and would tear it off the rocket and destroy the fabric and the bindings. So deploy that chute you really need to cut the velocity down to <130 m/s which you have to fire the retros anyway. Finally if you did both of these correctly, unless the winds aloft were perfectly predictable, your rocket lands a few 100 meters from the barge in the atlantic.

They push each engine past the rating, and there is no margin for error at those rates of deceleration, even off by 5% on one engine is a crash.

Fortunately earth does. The reason is because the rocket is traveling at an excessive speed with a high vertical component, too speedy to deploy until the landing burn has initiated. They could make the diverter planes larger and extendable to increase drag. Thats about it. You have to remember one thing, that rocket it plowing through variable upper level winds and surface winds. The slower it goes through there, the more off-target it will be, the faster it goes the closer its natural trajectory will be to the barge, if you could have drogue chutes slow it speed down greatly then what happens is the upper level ambient drift requires more lateral burn fuel to correct for any off course and equipment such as RCS to keep course.

They have a point where the nominal deceleration forces or the landing accelerations are going to converge on each other at a critical point. If you think about it the sooner they fire the less drag force has time to operate, and the more hoover time steals thrust, but if they wait too late, then they are going have super high g-force accelerations which will destroy the rocket and the margin of error on landings go way down, to the millisecond range, to the point were wave action will either spare the core or destroy it just by changing height a meter or so. I don't know if this is their game plan or not, but looks like they are heading in that general direction.

Nah, they are saying 'damn we just lost some cool crash video, I hate waiting, better go play some KSP.'

He's intentionally pushing things to the limit, once you establish a failure you establish a boundary, which you can improve upon or verify. There is no other reason because it appears they are not going to use any of these overstressed cores. When they used the word experimental it sounded like they were going to push the landing a little be further than previous. I think they are doing this so that they can estimate the minimum amount of fuel they need for safe return, therefore giving more capacity to the second stage. Obviously if there is underperforming engine, then they had remaining fuel either ejected or unsupplied. And like the other posters says they have two many used core at the moment to recycle and only one is from non-GTO. They've got pics, we just don't yet have them. BTW falling into the ocean is one way to cool things off, though water cannons are a much smarter approach, if you have a fuel system failure then the tanks may fill with water and your experiment ends up at the bottom of the Atlantic.

Well that is shorter. but less explanatory, ROFL.

How about caic-fs. Contact acceleration initiated collapse - fuel system involvement.

Im here and I think you are there.

reality is a perception of consciousness, everything is interpretive. You don't see colors , you brain colors things for you, hv that hit the rods and cones in your eyes react to hv, and there signals create the color reality. The same is true with sound. So the quantum reality makes sense at that level. But the quantum explanation. Fields have wave and particle properties, when quanta propogate they tend to have more wavelike properties, but under conversion the tend to behave like particles. Because of this they have to register discretely, we sort of demnd this, our eyes register photons, not waves. Observation forces an outcome. Non-determinism at the quantum level is the best support against simulation. So far only one theory, poorly supported, suggest there is determinism at quantum level. There is alot interest in this universe simulation, but like string theory, our current understanding does not support it.

-53 (-)

You are a funny little kook, why do you need one for earth? Its more of a benefit for rovers and equipment on other planets, and if its been done before why does it need to be done? Isn't that the point he wants to deliver earth like delivery capabilities except around or near mars. Defense contractors have a long history in the U.S. at creating markets that don't exist, you think procurement contracts are a one way street, remind you of the Mark-14 torpedo.

Still working on how to get the engine . . . .= vapor ware.

Banned for clicking dead-links.

-50 (-)

http://phys.org/news/2016-06-xenon-oxides-clues-paradox.html Xenon, just not on Earths surface.

The big payload companies know there will be failures, NASA had their fair share, and the competition in the last two years has not been doing that well. Not talking about a Mars Mission but an interplanetary capability that starts with some sort of Mars delivery, it could be as simple as an S-M L1(L2) communication satellite delivery. Your statement about running away in horror does not jibe, payload launching is not flying a Concorde, the only time people really freak out is when you screw up manned flights. I have seen so many failed launches that its just a accepted thing. For private space i'm somewhat amused when they don't fail. And why are you predicting SpaceX will constantly screw up their launches? Is this another one of those 'The UN is bad' statements you are inclined to make.

The proof of the pudding is in the eating, 1.) Lag effects 2.) Space-time limitations 3.) relevancy. 4.) uncertainty. OK so lets just say there is a trillion civilizations have exist so far the visible universe . So we create an object that is 14 billion light years in diameter. To the first 5 billion years of the universe, although the may exist in the comoving space that we now see as the first 5 billion years of the Universe, we will never see them. So now we are down to 250 billion or so. They may exist in a time frame that looks back to the beginning of the U and sees 13.8 billion years but they have no relevance at all to us. Next, lets talk about space-time limitations. Now lets just say that for any planet the likelihood of having sentients increases by a curvilinear function from 5billion to 13.8 billion post big bang. And lets next argue that in that window only 1/10th (very generous) of the civilzations that have ever existed still now exist (some live in galaxies that just went red, whatever) no fuel for new stars and their stars basically are now red giants, to far to travel between viable stars). So right off the bat we are down to 25 billion, but the problem is that as we move away from Milky Way the odds of there existence drops because we head down on the curve, and the ones we theoretically could observe will have a tendency to be in older more massive galaxies that are dying. so that drops the whole thing down to about 2.5 billion in terms of relevancy, they could be sending us messages like do-this, don't do that, whatever, but there would never be any communication, even if one had quantum FTL communication, it would be of no benefit because there would need to a common source for entangled particles. Next relevancy, without quantum communication using entangled pairs (which is probably not possible) we have to gain communication at great distances, the problem is how they communicate or think we might communicate, may not be how we could recieve communications. It is clear that our current technologies are inadequate for ly distance communications, again this is an area were there could be great improvements but we cannot predict the direction of those improvements, so when we look at all the theoretically identifyable things in our range 2.5 billion, we have to consider whether we could mesh with them in a communicative manner. The only thing that I could imagine was an extremely powerful culture that could send quantum space-time signals from black holes by dropping large objects into the black hole, or something like this. This would be an obvious signal, but unfortunately would consume the galaxy, and the message would spread every direction, and they would have no idea if it was ever recieved. The message might be this 'Don't try to communicate by driving mass into a GBH'. The alternative is they could laser target stars with a unique laser energy, some kind of laboratory metal that sends out a unique frequency, problem is this again needs to be targeted to a position where our star(s) will be when the laser light tracks the system. Again we don't know the frequency of the special metal and are we sophisticated enough to detect the signal, calculated its and ours comoving space time difference, back calculate the sending frequency and then determine which very rare or unnatural mineral created the light. This uses less energy but the problem is you need to a conversion of one kind of power into light, that uses alot of power. So basically I have to argue that communicating between galaxies is both energetic and not very frugal with sources that are needed for space civilzations to survive, remember that the key essential element for survival in space is energy. So this basically knocks down relevent life to our galaxy and a few local clusters, millions of potential sentient species. Next uncertainty, What if the drake equation is just a big screw up, what if life is far less common than we think, we know now, looking at other systems, some with hostile stars, and others with massive planets or with planets that are just too hot, that we greatly overestimated the possibility of life, that even planets with life more are marginal (e.g. mars like) for life in the past, a tiny rare minority are stabile under both tropical and long-lived enough to produce sentients. Since I can't address this starting with millions of sentients in our galaxy. There are places in our galaxy and local clusters that are just hard to see, to much dust, gas and other stars between us and them. So lets say that in that range maybe we have a perceptive line of sight 1/4 (I think im being generous) of the sentients in the galaxy or visible globular star clusters. So that takes us about a million, I would say maximum, perceivable lines of sight. But there are 300 billion stars in the galaxy and we only therefore can see 1 in 300,000 of these might have sentients. Some of these might not be space faring, because of the physics of their planets, or lack of resources. Others may have extensive cloud cover, or the sentients might be more philosophical and less technical. So lets say that such sentients exist on 1 in 300,000 stars how far would be have to travel to find them. Very crude calculation basically we have to travel 100 light years or so to find this culture. Hey, they could be sending us a very strong signal right at the moment, oh, but wait, why would they send a signal to earth, cause 100 years ago we basically were sending things out at long distances by morse code and crude wireless signals. So why would they think we even exist. I granted 10% of all that lived are still alive, but that means that are still alive are probably much more evolved communications, so could we detect them if they were signalling, maybe they are sending out the universal 'don't call us will call you when you figure out the code' signal. So from our point of view we might have to evolve another 10,000 years to be able to decipher the random-looking encryption they use. Or it may not be random at all, it might just appear to us that way, for them it might be hyper-efficient compression that you need sophisticated equipment to decompress. So then we fall back on maybe we can passively observe them from Earth. So the earth travels around the sun at 150,000,000,000 meters. The half circumferance is around 500,000,000,000 meters. For us to detect them crossing in front of their star the have to pass 700,000,000 meters. So the odds of seeing a star passing in front of their star along our line of sight is 0.0014. OK so the maximum likelihood we would see an sentient civilizations planet in transect is now between 500 and 1000 light years away. So now given this we would need to survey 1,000,000,000 star-planets with the hopes of finding one with sentient life. Given this: how hard would it be to communicate 750 light years 1. round trip communication would be 1500 years 2. Probably not passive. How about detection, could we passively detect sentients. 1. Artificial satellites are invisible at great distance 2. Interplanetary probes are excessively rare, and may not come with a roadmap back to the sender, and may not be a star recognized as having sentient life it if did. Most interplanetary probes are in interplanetary space, because of the gravity well they little time in the habitable zone, would be difficult to capture if they did. Note a hawkings-flyer would zip right by us and at 0.2c we would not see it unless it collided with something, in which case we might see a dramatic poof. 3. Organic signatures are ambiguous. 4. Should you be lucky you might capture a culture ending nuclear war, but that would obviate the whole reason for the search. The critique here is how far between two points in space would passive identifiers be detectable, lets just say that within 20 ly passive detection is possible, the probability that two planets with sentient life exist within that distance is around 1/100,000 or so. So it is very unlikely the Earth might know this, but the problem is that if our signals reached them, now, you have outcomes. They received the signals, say 60 years ago and: a. misinterpret them as something else (scientific lag) b. have decided to ban all communications with similar equipment so that we cannot detect them. (they are shy) c. have sent a reply and we did not notice is and they took it as a snub. (they are snobbish) b. have gone on radio black out as they (in about 750(0)(00) years) attack us. (they are aggressive paranoids) e. they are attempting to communicate with us via some spiritual process and for whatever reasons its not realized or public. f. they have already visited the planet but observe from great distance and have yet to decide that we are not yet worthy. What we see is the sentient life problem becomes an issue of technological steps. Easily observed exo-sentients are hard to predict based on stars, the closest are probably greatly obscured from us, but far enough away, probablisitically speaking, that they or us would have to seek communication to detect them. The odds of them, based on our technology, not seeing us and us not seeing them is around 99.7%, the odds of either one of the two seeing the other one is about 0.25%. Therefore we would have to communicate with all potential stars (not just those that have transecting planets) in the vicinity of about 200 light years hoping that we are communicating with an sentient life, again we need that special technology that tells them, 'we are not noise, we have lasers and can make this artificial element and use it in a laser'. Outside of that range would be the dyson ring range, were you see a very rare and powerful civilization which is probably in the range of 10,000s of light years away (if they are at all possible). This is the maximum extent of the zone of relevancy, things further away would be irrelevant to us. THe so-called civil universe is much smaller than the observable universe. When we start the directed communication the response times could be 100s to 1000s of years, and the responses may not be what we expect. Thus that adds uncertainty. So it begs the question are we even addressing the question properly. Should we not play the devil's advocate? There is no relevant sentient life, prove otherwise (my stance). And if this was the case how would we find adequate proof.(Disprove the null hypothesis). 1. Improve telescopic methods (If you know me, I have been suggesting better telescopes as a game addition, I a champion of Hubble and I have proposed that we should have massive telescopes in space that cover 100s of meter) in the light and ultraviolet range. 2. Radio-telescopes on natural satellites that are not perturbed by communications here on earth or atmospheric interference. 3. A more systematic search of adjacent stars for planets, but a focus on stars like ours and a thinner habitable zone. IOW looking more broadly but being much more selective and much more focus on direct measures versus indirect measures. This might include placing telescopes in interplanetary space. 4. A focus on modernizing interplanetary communication, technological improvements in communication methods as to understand how sentients might communicate. Quantum teleportation/communication is still a place of rich expansion.

BTW, an electric hybrid, plug in, is a mid-sized car that can get 100 mpg.

I think that fortunately for SpaceX/Musk they have put alot more thought into these things than you (or me). Armchair rocket scientist fears and pictures of soviet era rockets are no predictor of future success. I think that one thing they have that you don't have, that would be data, experience (much from test firings). I can't tell you what is a better strategy, RP-1 of lH2 but I can tell you that there performance is close enough together, it if was cost effective they could produce large cores, and anyone who doubts Musk can pull it off would be fooled. So that primarily your fears are not the issue, I'm sure they are looking at costs, if they can send 9 things into space link them up cheaper, or do they need to launch everything at once. This effort is going to be made on the margin, unless NASA or some other GO decides to ante up, so its going to be about cost, if they fail, they will have to wait 2 years to retry on the cost margin. And I think Musk is looking at something else you are not looking, to be the supplier of interplanetary stocks and payload, so from that perspective he could write of cost/failures as cost of services sold. So just maybe over the next 2 years he will be investigating the market in that direction to see if there is interest. I see ESA, politically he would have to crack a barrier, NASA nothing yet but it could change, possible ISRU. If NASA ante's up then at least they could have contractual control of who else might get a ride, but that potential would be non-existent if the boca-chica site opens up. So to answer your question, what much more important is whether they can keep on schedule and potentially expand launch in the next to year to get the required margin.