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Buran was not a copy of the Space Shuttle orbiter, as you should know, but a next generational development, including the tiles, which were not as fragile as the ones we are compelled to keep on using, so the above arguments regarding falling foam damage don't necessarily apply.
Buran could achieve a 1,700 km cross range on re-entry, protected by 39,000 tiles of two types. Synthetic quartz fibre tiles were used in low temperature areas, and black high-temperature organic fibre tiles were used on high temperature areas. Carbon-carbon material was used for the nose and wing leading edges.
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"Carbon-carbon material was used for the nose and wing leading edges"
Same as the American Space Shuttle... There was nothing "next generation" about Bruan at all.
"Heads up means gravity pulls foam down away from a heads up orbiter... doubt you would understand"
Shuttle and Bruan sit at exactly the same angle, similar distance, and almost identical shapes. It is only logical that both would be subject to the same problem as the other in this respect. The burden of proof is on you to explain why this is not so. And "ohhh but you wouldn't understand" etc etc is not how you debate young man. You don't know what I can do... how about you dig up one of these many papers you cite, which I bet don't exsist.
"And your Delta IV taking 40 tons to LEO lie"
I am not even going to justify such whining anymore Publiusr. A single Delta-IV core can do ~8MT but about 25% more with a pair of small SRMs... three of them should be able to do about as much, or did you fail grade school math? You have agreed yourself that Delta is thrust-limited, so if you bump up the thrust at launch, you get a big payload improvement... With improved engines with higher Isp and thrust, >12MT should be easy.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Oh, please guys, try to keep it civil.
The Shuttle looses tiles during the first phase of launch, before it's roll maneouver. That means it doesn't matter if it's on its back or belly after the roll. Orientation makes no difference for Buran vs. Shuttle. I don't know what insulation Energia uses so I can't comment on foam problems.
Shuttle has 2 types of HRSI tiles: 9 pounds per square foot, and 22 pounds per square foot. Both provide equal thermal protection but the heavy tiles are more durable. FRCI tiles are 10% lighter than the heavy HRSI tiles, but 3 times as strong vs. impact damage. FRCI was initially used close to the engines but 22 lb/sq ft HRSI tiles are being replaced by FRCI by attrition. I'm not sure if lost 9 lb/sq ft HRSI tiles are also replaced by FRCI.
As for the "all mighty Buran" it was designed with a tile pattern that permitted slightly less hot gas infiltration, and did have slighter higher lift:drag ratio, and slightly higher cargo mass. The higher cargo mass was due to placing the main engines on the external tank, making them expendable, as well as 4 main engines instead of 3. The 4 liquid strap-on boosters were usable 10 times, and had a lower refurbishment cost than Shuttle's SRBs. That is an estimated lower refurbishment cost, Buran only flew once. Buran was designed to be competative with Shuttle, but the fundamental design of both is not economical. Energia can lift 88 tonnes to 200km orbit without Buran, or 30 tonnes with.
Delta IV Heavy with 3 CCBs and a larger upper stage can lift 25.8 tonnes to 185km orbit. The http://www.astronautix.com/lvfam/delta.htm]Delta family listed on Astronautix now includes several Delta IV Heavy upgrades. One is the version GCNR talks about, 3 CCBs with RS-68R engines, 4 GEM 60 solid boosters, and cryogenic hydrogen densification. There are even larger versions, check the link.
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Nice things to know, but the real issue being debated here are those RCC pannels around the wing leading edge and nose structures: publiusr here is claiming that Bruan sits in something called a "heads up" configuration as opposed to the STS, which would mitigate or eliminate the risk of RCC damage if debries seperated from the tank like with Columbia.
I am affirming that publiusr is a liar who just made this up and is trying very hard to make Energia "special" and NASA look stupid while himself appearing to be professional in the field. The shape, tank mounting, and RCC systems on both Bruan and STS are almost identical, and that no such "heads up" difference exsists. Publiusr claims that there are aerospace engineering journal articles that detail this difference and claims that "you wouldn't understand" as a means of arogantly trying to deflect further criticism to his statement.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Engine placement could very well result in a heads-up orientation rather than "on its back". The Shuttle's offset engines create a thrust line that passed from engines through the external tank, so during angled flight toward orbit the engines must be under the tank. Energia's engines are on the external tank, so its center of mass passes from engines under the core module to somewhere between the nose of the orbiter and nose of the core module's oxygen tank. It doesn't matter, Shuttle tile loss is before the roll manoeuvre. That means foam is lost during vertical ascent, before pitching over. During that phase of flight there is no difference between Buran and Shuttle.
Here's a http://www.buran.ru/htm/compare.htm]comparison of Space Shuttle vs. Energia-Buran from Molniya, manufacturer of the Buran orbiter. I don't see how tile loss would be any different on Buran. Both orbiters use reinforced carbon-carbon for leading edges. Molniya gives strength figures for theirs and claim it's stronger than the American version, but I doubt it's significantly different.
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Exactly, during the liftoff with the most stressful and high-vibration time of the acent, both vehicles are flying exactly the same direction, about same acceleration, same shape, same wing leading edge materials, same vunerability. I would imagine that the aerodynamics of debries seperation would be very similar too, no matter what direction you are flying.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Nice things to know, but the real issue being debated here are those RCC pannels around the wing leading edge and nose structures: publiusr here is claiming that Bruan sits in something called a "heads up" configuration as opposed to the STS, which would mitigate or eliminate the risk of RCC damage if debries seperated from the tank like with Columbia.
I am affirming that publiusr is a liar who just made this up and is trying very hard to make Energia "special" and NASA look stupid
You just don't get it.
Lets play a game folks.
Suppose Mr. 'Revenger is flying below a jumbo jet shedding ice. I am flying above it. We both have slipstream--which might fling some mist and small ice particles on both of us--but he has to contend with both gravity and airflow.
Whey he is too stupid to understand this is his problem.
NASA is not stupid, for they felt that heads down allowed better comlinks in pre TDRS days.
There have been plenty of talk about the advantages of heads up flight. Just look up some of the older issues of JOURNAL OF SPACECRAFT & ROCKETS and look.
remember, Mr. Revenger all but called me a lier when I stated that VentureStar was to have external payload pods like Energiya. He put Lockheed Secret Pprojects in quotes.
Until I posted the link that proved him wrong.
To which he didn't respond.
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Lets play a game folks.
Suppose Mr. 'Revenger is flying below a jumbo jet shedding ice. I am flying above it. We both have slipstream--which might fling some mist and small ice particles on both of us--but he has to contend with both gravity and airflow.
Whey he is too stupid to understand this is his problem.
I have a little game here, too.
Let's actually model the orbiter-ET system, rather than making the gross oversimplification of flying above or below a jumbo jet. The ET and orbiter are incredibly close together. The flight angle is fairly close to vertical at the 81 second mark (regardless of whether it's heads-up or heads-down.) The falling foam will have velocity components in both the horizontaland vertical directions. The exact path the foam takes is influenced heavily by the flow field between the orbiter and ET. It's also influenced by the ballistic coefficient of the shape of the piece of foam.
Now it's become a much harder problem. The orientation of the vehicle is seemingly inconsequential when compared to all of the other variables in the equation. The relative trajectories of the foam and orbiter will likely be on a path towards a head-on collision.
Please learn more about physics before you start making inflamatory claims and cutting people down.
Who needs Michael Griffin when you can have Peter Griffin? Catch "Family Guy" Sunday nights on FOX.
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Exactly, the "heads up = good" idea is a radical, gross, amerature oversimplification. Considering the low density of the foam would make it very easy to influence aerodynamically. Hence, it really wouldn't matter what direction you are flying. Rain drops, which are much denser then foam chunks, are blown up and over your car when you are driving in the rain at 100km/hr... imagine what it would do at low/mid Mach numbers?
Secondly, during the part of acent most likly to cause foam damage like Columbia (near Max-Q I think its called), let me say this very clearly Publiusr, so perhaps your "Buran= Good, STS = Bad" brain can comprihend:
-Shuttle and Energia are flying straight up, perpandicularly to gravity, very close to 90 degrees.
-So, there is no "heads up" nor "heads down"
-So, there is no difference between Buran and STS
-So, your basis for there being a radical difference is simply nonsense, and you have no more basis for further arguments
Simple enough? Maybe I can make it even easier: "Buran + Zenit = STS - SRB"
Even after the pitch over/booster eject maneuver to line up with the desired orbital path, the angle does not suddenly change, so there is still no difference for some time, after the danger has passed.
"Just look up some of the older issues of JOURNAL OF SPACECRAFT & ROCKETS and look."
Nooo, when you cite a journal article, you list the exact page number. Well, at least scientists and engineers who want to be taken seriously will. An breif sample of the relevent paragraph or including the abstract doesn't hurt either.
"He put Lockheed Secret Pprojects in quotes."
Which I still think you are talking out the wrong side of your head, since if it were a secret "pproject," then you obviously wouldn't know about it. Conspiracy theories etc etc.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Here is the citation--which speaks about Heads-Up vs. Heads Down ascent. Since they are not the same--and since the shuttle does not fly straight-up--there is a difference, and you are therefore proved wrong.
It's the Delta IV which has a problem kicking over--that rises 90 deg and puts its pad in danger. And is astronauts--thus the concern from the astronaut office.
Page 250 May-June 1988
J. SPACECRAFT
"Shuttle Performance With A Heads-Up Ascent."
Vol 25 No 3
I've done your homework for you, after digging around. It talks mostly about lift changes. There has been talk about heads-up vs. heads down all over NASA.
Will you at least admit there was every possibility that it could have dropped a bit--and that the foam that just hit the leading edge could have just missed it. If you had heads up--especially a bit later in the flight. Common Sense.
I also noticed that Mr. Revenger never responded to my having corrected him on his not believing that VentureStar wouldn't also have had external side-mount payloads--with OSP being in the same position as Buran. From the Lockheed Secret Projects book and the website I linked to.
And it is a book written by a man named Jenkins, who also wrote a comprehensive history on the Shuttle.
Or perhaps you don't believe that either.
BTW-- The latest Space News has a nice article on another Ares--not Zubrins SDV HLLV, but a small fly-back like booster that also has a piggy-back payload, BTW.
Nice artwork there--to steer this back to topic.
I never said "Buran good STS bad." You are the one who said that.
I just pointed out that that Buran is just one of many payloads Energiya could fly--and that it is a better system. You are the one cutting people down for daring to bring up valid points. At least if a Buran orbiter had failed, we would still have an HLLV--and if we had Zenit, we could have had an EELV a long time ago. Both Boeing and Lock-Mart use Zenit tech in some way.
I cannot believe how dense you are. It must take practice.
I simply respect the modular nature of the Russian design. That I am not alone on this point is obvious--a lot of people respect Russian tech.
The current SDV lacks an orbiter anyway--which should make you happy.
So shut the hell up.
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"shuttle does not fly straight-up"
Not true. Shuttle does fly essentially straight up (as well as Buran), and does so during the most stressful period (liftoff) of flight where debries damage is going to occur, so there is no real safety difference as I have maintained.
You have so completly latched on to this idea of heads up/down being some end-all/be-all, that you ignore what actually happens. This strongly suggests to me, being that you haven't a overall picture of what is going on, that you really don't know what you are talking about.
The Shuttle is barely off vertical after the first whole minute of acent, through the point of maximum acceleration (Max-Q I think its called), through the sound barrier, and through most of the extreme vibration of the SRBs firing. This is aproximatly when Columbia and Atlantis both took their collective three foam impacts, with the Columbia tragedy being the third... Same deal with Buran too.
Frankly, I think you just Googled an article with the title that contains the phrase "heads up" and didn't even bother to read it. Why didn't you cite your article earlier? Your lack of real knowledge of the subject suggests that you are not an expert in the field, and probobly wouldn't properly understand a technical journal article anyway... Not that it applies much anyway, since it is concerning to performance and not safety.
No, no I don't think that its "Common Sense," since the aerodynamics are very likly the overriding dominant force, with gravity being only a minor one. You yourself have suggested that aerodynamics would be a factor, and they are not dependant on the orientation of the vehicle. Being that supersonic air carries a huge amount of energy compared to the kenetic energy of a piece of low-density foam falling <50ft due to gravity, I believe it is entirely reasonable to assume gravity is irrelivant. It is certainly worth questioning, and not at all "Common Sense", especially given that the acent angle is almost straight up.
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"It's the Delta IV which has a problem kicking over"
Thats okay though, the SRMs or an uprated RS-68 will fix that issue. With the much higher takeoff thrust, you can clear the pad quickly. Saturn didn't lift off th
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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What goes around comes around--you told me to shut up after all--I just muad the mistake of lowering myself to your level. And no--I did not google that--and Common Sense still pervails--sense you so obviously lack.
Gravity still exists whehter you deign to believe it or not CFD purists or otherwise. There is every reason to believe that piece of foam would have passed just below the orbiter had it been flying heads up.
There are advantages that have nothing to do with foam strikes--now that the leading culprit (the ramp) has been fixed.
Any TSTO will have to face insulation problems, and heads-up ascent will help whether you choose to believe it or not.
To get back on topic--on the subject of HLLV artwork--these links may be helpful:
http://www.braeunig.us/space/index.htm] … /index.htm
I think this next link still works:
Sea Dragon:
http://up-ship.com/images/profilessmall … maller.gif
Nice artwork.
BTW--did you call yourself "lexcorp" in another life 'revenger?'
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Nope. Unless you can account for the majority of all the forces involved with te dynamics of falling foam, then you haven't any basis to claim any particular direction foam will go. Gravity isn't even a factor at all during the most dangerous part of acent since the vehicles are both flying straight up.
The performance differences between heads-up or heads-down mounting aren't at issue here, its the safety of the exsisting vehicles. Insulation will continue to fall off of the tank, even NASA admits this, they are just trying to control the size of the bits so none big enough to kill the vehicle fall.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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It's a moot point now anyway. Future TSTO designers will pick up on this debate.The orbiter is going to be nixed--and that will save quite a bit of money making SDV HLLV competitive.
The "stick" is certainly spartan enough.
The next winged concept we MIGHT see:
http://www.dogpile.com/info.dogpl/searc … ...acelift
http://www.aero.org/news/newsitems/ARES … 28-05.html
http://www.globalsecurity.org/space/sys … s/ares.htm
OT
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