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#51
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"David E. Powell" wrote:
Did western antitank planes rely more on bombs and rockets? (Outside the P-39 of course?) DEP Of course not. There were upgunned Hurricanes, and numerous fighters and light and medium bombers outfitted as strafers/gunships. The 37mm gun on the Airacobra/Kingcobra was a contraversial weapon to the Americans (some pilots liked it and many didn't), and it was generally thought that anything bigger than 20mm on a combat airplane was effete. Perhaps it was more of a logistics issue than anything else...since the .50 caliber machine gun seemed to be adequate in a general-purpose sense, why upgrade? The Allies (in particular the Americans) never fielded a specifically anti-armor airplane in spite of going through dozens of designs. Simply fitting bomb racks and rocket rails on a day fighter--or packing extra machine guns on a medium bomber--made more sense from a production standpoint than having a specialized type created and put into action. Allied wartime CAS thinking ultimately resulted in the Douglas Skyraider. We'll never know what a plane like that would have done on the Western Front, but to me it would have done what the Thunderbolt, Typhoon, Tempest, Beaufighter, Mosquito and Mustang did...and more of it. Stephen "FPilot" Bierce/IPMS #35922 {Sig Quotes Removed on Request} |
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![]() Alistair Gunn wrote: Kristan Roberge twisted the electrons to say: Well columbia's solution would have been to park to the ISS and stay there until NASA can get their arse in gear and rush another orbiter into orbit... ... and where does Columbia find the fuel to do this? there's no rule that says you have to RUSH to a higher orbit. |
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Kristan Roberge wrote:
Alistair Gunn wrote: Kristan Roberge twisted the electrons to say: Well columbia's solution would have been to park to the ISS and stay there until NASA can get their arse in gear and rush another orbiter into orbit... ... and where does Columbia find the fuel to do this? there's no rule that says you have to RUSH to a higher orbit. Delta-v is delta-v, and Columbia didn't have enough to get to ISS, period. The speed of the proposed manuver is irrelevant. To go from Columbia's original orbital inclination to the orbital inclination of the ISS would have demanded a plane-change maneuver requiring far more fuel than the shuttle's Orbital Maneuvering System carries (at least 4 times as much, fuel, as it happens). This proposal has of course come up before, and George Herbert was kind enough to do the math: http://groups.google.com/groups?selm...utput =gplain -- Tom Schoene Replace "invalid" with "net" to e-mail "Our country, right or wrong. When right, to be kept right, when wrong to be put right." - Senator Carl Schurz, 1872 |
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"John Mullen" wrote in message ...
"Steve Hix" wrote in message ... In article , Kristan Roberge wrote: As to Challenger, my understanding of post accident investigations were that the crew were pretty much all recovered together, and still strapped to their seats in the cabin, and that they may have still been alive post explosion (though unconscious). An ejection seat system that could have blown them clear of the crew compartment in such a major system failure would possible have been useful. So much for any useful payload... Yeah, seven ejector seats would not have worked. On the other hand, it is mind-boggling that they had not even given any thought to the possibility of abandoning it in flight... It is at least possible that simple parachutes and a bail-out pole might have saved them, such as are now installed. John The US had a series of clamshell ejection seats for the B58 Hustler, XB70 Valkyrie and X15 that could handle Mach 5.5. They worked to. Plans for even more capable ejection seats based on this series were afoot. Surely these would have saved the crew? The Gemini Style ejection seats of the Gemini Capsule and SR71 handled in excess of Mach 3. The EGRESS system based on these clamshell seats added a heat shield to the rear and was capable fo full re-entry from orbit. It is difficult to imagine the seat not managing most situations except a very rapid disintegration. This is EGRESS: http://www.astronautix.com/craft/egress.htm http://www.astronautix.com/craftfam/rescue.htm The lack of ejections seats on the shuttle was purely an economic one: it allowed either more crew or more payload. |
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#57
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![]() Sorry for taking so long, but I was lining up some ducks... In article , "John Mullen" writes: "Peter Stickney" wrote in message ... In article , "John Mullen" writes: "Emilio" wrote in message ... Actually they admitted they copied the US Shuttle. More I think about Buran, it is clear that the politician who decided to "copy" the shuttle and not the engineers. Russian industry simply was not setup to produce space qualified $20 nuts and bolts like we do. If they made special run to make such nuts and bolts it would have cost them $100 a peace. Buran must have been reengineered to be able for them to build it there. That's a problem though. It's going to get heavier than a US shuttle. Reentry and flight parameters will no longer be the same do to added weight. It's amazing that they made it to work in the first place. Actually, it was a superior design to the STS it was copied from. Heavier payload, more crew space and less rinky-dink stuff to blow up like the ET and the SRBs. Just teh Big Honkin' booster it was hooked to. Both configurations have their advantages, and their risks. I can't think of any advantages to the STS's layout. What did you mean here? Just off the top of my head - better alignment of teh Main Engine's thrust lines with the CG of the entire stack. This gives you less problems with control, and more tolerance of off-normal conditions. (Such as losing a Main Engine - it's happened once on STS) Concentration of teh Guidance & COntrol systems in a single, integrated system, rather than having two independant systems that have to try to talk to each other. Keeping the expensive, reusable bits in one place, and throwing away the cheap stuff. (As it turns out, this didn't work out as well as originally expected - rather than a clear advantage wrt reusing STS SSMEs vs. the Energia's cheaper, (but still not cheap) expendables, it seems to be pretty much of a wash. Well, the Astronauts never flew it. That tells you something. Buran: 1 unmanned flight, total success. Not a total success - teh flight article was structurally damaged on re-entry. I don't know if repair was possible. That is news to me. See for example: http://www.astronautix.com/craft/buran.htm Mark Wade quote excized Could you be mistaken? Or is this fairly new info? If the latter, I would be interested in knowing your source. No, I'm not mistaken. It's not new info, although teh (then) Soviets weren't too big on publishing it. There are various sources, but the best place to go, if you can read Russian, is the Official Buran site: Http://www.buran.ru/ Even if you don't read Russian, here are some post-flight images of Buran: http://www.buran.ru/images/jpg/posle01.jpg http://www.buran.ru/images/jpg/posle02.jpg http://www.buran.ru/images/jpg/posle03.jpg http://www.buran.ru/images/jpg/posle04.jpg http://www.buran.ru/images/jpg/posle05.jpg http://www.buran.ru/images/jpg/posle06.jpg http://www.buran.ru/images/jpg/posle07.jpg http://www.buran.ru/images/jpg/posle08.jpg http://www.buran.ru/images/jpg/posle09.jpg http://www.buran.ru/images/jpg/posle10.jpg http://www.buran.ru/images/jpg/posle11.jpg http://www.buran.ru/images/jpg/posle12.jpg http://www.buran.ru/images/jpg/posle13.jpg http://www.buran.ru/images/jpg/posle14.jpg http://www.buran.ru/images/jpg/posle15.jpg While most of them are pretty ordinary - some damage occurs on any flight, pay special attention to image 15. That's a breach of teh wing structure, caused by poor joints between the Carbon-Carbon Leading Edge and the Ceramic Tiles that cover most of the wing skin. The Russians were fairly coy about the internal damage, but from the scarring and marks left by hte exiting material, it wasn't trivial. At best, you're talking about rebuilding/replacing the wing. At worst, it goes to Monino and you fly the #2 flight article. Thay're lucky that it occurred out toward the wingtip. If it had been where the chine & the wing come together, where the shock impingement from the bow shock occurs, (And where Columbia's damage occurred), it would have been much, much worse. STS ~100 manned flights, two total losses, 14 deaths. A hair over a 98% success rate, a bit better than Soyuz (Which also had 2 fatal flights, with 100% crew loss on each, (But smaller crews), and several launch aborts. And a number of nasty landing incidents. Really? I cannot easily find a total for the number of Soyuz missions but feel sure it must be way over the 100-odd of the STS. Do you have better figures? Currently, the number is 90 Soyuz flights, and 112 Shuttle flights. http://space.kursknet.ru/cosmos/english/main.sht hads been keeping a running total, valid through late May, 2004. (no flights since then) And to me the survivable aborts are an indication of the robustness of the 1960s design. The people on Challenger would have loved a surviveable abort system. The people on Columbia would have loved merely to have suffered a nasty landing incident. They're not really relevant - every vehicle, from a Skateboard to a Shuttle, has failure modes which are not survivable. If the aborts had taken place at a slightly different time, or the reentry and landing incidents, like the time a Soyuz Service Module didn't detach after retrofire, causing the Soyusz to reenter not heatshield first, but Aluminum hatch cover first (The SM burned away, allowing the spacecraft to reorient itself before the crew was lost), and the guidance problems that have caused some reentries to occur hundreds of miles off from their targets could very easily have been much worse. Aviation, and especially Spaceflight, is all about tradeoffs. What sorts of system could have been aboard Challenger that would have extended the survival envelope significantly, and wouldn't have been a hazard during most of the flight? And which wouldnt' require some compromise of the stucture? What system could possible have turned Columbia's loss to a nasty landing incident? I don't see any systems that would allow a successful bailout at Mach 25/200,000'. (You could, I suppose, postulate something like MOOSE, but that's only useful before the retro burn occurs) (I never mentioned Soyuz btw!) Whenever the "Two Accidents, 100% crew loss" line comes up, a comparison with Soyuz reliability is not far behind. There's no reasonable comparison to anything else, after all. Buran made 1 limited flight, got broken, although the full extent still isn't known, during that flight, and sat in the assemble building until the building collapsed on it. There's no objective indication that the expendable Soyuz capsule is any safer than the STS. Er.. how about the fact that the STS is currently grounded for safety improvements after the last fatal crash? Leaving Soyuz as the world's only manned orbital vehicle, other than the Chinese and maybe Bert Rutan! That's not objective, it's subjective. Because the Russians, (and for that matter, us) are willing to accept the risks that flying Soyuz right now represent. That doesn't make it risk-free. Anytime you fly anything, whether it's a kite or a 747 with 500 people aboard, or a spacecraft, you run the risk of a fatal crash. If you fly something enough, it becomes pretty much certain that you'll crash it. To a large extent, it's a question of whether the risk is perceived to be sufficiently minimized. Here in the U.S., we see that there are steps that can be taken to reduce the risk of Shuttle flights, and we'er willing to take the time to implement them. I don't think there's a lot that you can do to make a Soyuz less risky. (Which does not make it risk free). As for Burt Rutan, please don't make the mistake that SpaceShipOne is the harbinger of entry into orbit. It's not. The design is very heavily optimized for a single, very limited goal - getting an X-prize equivalent mass to 100 km altitude. The peak Mach Numbers for SS1 are down around Mach 2, the materials are all conventional, and the "shuttlecock" re-entry profile isn't going to hack Mach 25. Don't get me wrong, it's an excellent achievment, but useful Space Travel it isn't. I'd say the Russians realised they had no need of a shuttle and quit while they were ahead. More like they couldn't afford it. Both Buran and Energia (The booster) Well sure. It is true that their country did collapse during the devlopment of the Buran and Energia projects, leading to their cancellation. My point was that this wasn't because they were inferior kit, quite the contrary. But there also isn't enough sample size to claim with any validity that it was superior, either. -- Pete Stickney A strong conviction that something must be done is the parent of many bad measures. -- Daniel Webster |
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#59
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On Mon, 14 Jun 2004 06:25:55 GMT, Kristan Roberge wrote:
Alistair Gunn wrote: Kristan Roberge twisted the electrons to say: Well columbia's solution would have been to park to the ISS and stay there until NASA can get their arse in gear and rush another orbiter into orbit... ... and where does Columbia find the fuel to do this? there's no rule that says you have to RUSH to a higher orbit. The orbits are radically different, the Shuttle could not have come close to the ISS. Not even "slowly" (as if that would matter). Al Minyard |
#60
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Alan Minyard wrote in message . ..
On 13 Jun 2004 10:52:07 -0700, (robert arndt) wrote: The Hungarians may have had their own indigneous project. Don't forget they did have the worlds first turboprop in the 1930s. It worked but had problems with the combustion chamber burn through. Someting that could only be solved with hard work on the test stand or good alloys. And which turboprop would that be? My understanding is the british did it first, and it was in the 1940s. The Jendrassic CS-1 designed in 1938 and tested in August 1940. The war stopped its production even though a specific aircraft was designed to fly with it- the Hungarian RMI-1 X/H which was fitted with DB engines instead and destroyed in a bombing raid. Rob \ In other words, it never flew and was just another failed project. Al Minyard Hungarian, Gyorgy Jendrassik who worked for the Ganz wagon works in Budapest designed the very first working turboprop engine in 1938. Called the Cs-1, Jendrassik's engine was first tested in August of 1940; the Cs-1 was abandoned in 1941 without going into production due to the War. Max Mueller designed the first turboprop engine that went into production in 1942. He will forever be remembered for making the worlds first turbo-prop. At the time the little nation of Hungary was well ahead of the USA and the UK in this field. One wonders what would have happened had the USA and UK had a Soviet army 10 times the size bearing down on them. Their turbo-prop engine worked but had combustion difficulties and power and life were well down. Wheras the Germans had the resources to build the massive test chambers (complete with multimega****t refrigeration, water spray, alitude, instrumentation, wind tunnels etc) to make the adjustments the Hungarians did not. There is a picture of it he http://tanks45.tripod.com/Jets45/Lis...ginesOther.htm I believe the very influential German Engineer Max Mueller designed the first turboprop engine that went into production (for a test program) in 1942 most likely under Heinkel. (he changed employment from Junkers, Heinkel and Porche) I'd have to check my sources though. |
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