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#41
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Moscow...we have a problem.
On Sun, 20 Nov 2011 22:03:08 +0000, Dr J R Stockton
wrote: Then one does not use that type of propellant; one uses a system that stores better. There are solids, hypergolics, and cryogenics. Solids we've discussed. Hypergolics are toxic and corrosive (a Titan II exploded in its silo in Arkansas). Cryogenics are difficult to store for long periods of time due to high boil-off rates. What else is there? But I was not proposing making a few launchers and keeping them on standby for decades, as the USG wants for ICBMs. Instead, after a relatively short period of storage, each one is used for a routine launch. No rockets are standardized that way. Rockets are very expensive. The launch industry wants to get every penny and pound out of their rockets as they can, and each one is essentially custom made. A rocket built to launch a Boeing satellite can't be used to launch an Astrium satellite, at least not without a lot of modification, which defeats the purpose. The Federal US needs the capability to introduce a new class of launcher. It did that in the seventies (+-), with STS. It thought that it could do that with Ares and Constellation. It may be able to do that with the new SLS; but we need to wait for a year of the next Presidency to know whether to believe it. Shuttle was a failure. Ares was a failure. SLS will almost certainly be a failure. Now you want the government to try again? Who's going to pay for this. Us taxpayers? Pass the cost on to the satellite industry? All that would do is force the industry to move to China and India, which won't give a hoot about having to pay for standby satellite rescue systems. Those who need such things should pay. They will certainly say they don't need them. So do you order them to pay? How? They'll just buy launches from China, India, or Russia instead, and it is a certainty China and Russia will turn a blind eye to the problem. The problem won't go away. His system is new, and naturally things are slow, and many delays seem to be occasioned Federally. His system must obey the same laws of physics as everyone else's system. So far, the only organization that has shown the very high launch rates Musk insists he can meet, is the U.S.S.R. Musk doesn't have the ability to send underperformers off to the Gulag. I must insist we wait until SpaceX has actually launched more than a couple of large rockets before we declare them the be-all and end-all of space launch. Ariane V is not fast. One of their launch campaigns is still measure in months from hardware arrival at Kourou to launch. Ariane V and Atlas 5 both go to the pad fairly shortly before launch, but that's just the end of a long launch campaign. I think not. Ariane has plenty of payloads booked, Booked years in advance, with rockets custom tailored to the customer's payload. and so has no call to keep launchers hanging around ready to go. If a reliable customer were to ask for a launch-in-a-month capability, or in a day, then no doubt Arianespace would be able, after contemplation, to offer an appropriate price. That price would be gargantuan, and years down the road, as it will require an entirely new infrastructure. No customer is going to pay this huge bill in the off-chance one of their satellites goes kaput in orbit. The problem is not so much the rockets (although maintaining an ICBM on standby 24/7 is far from cheap or easy) but the spacecraft. Then either design the satellites for the conditions, Much, much, MUCH easier said than done. If that were practical, it would already be done. or fuel and attach the satellites only when a launch is imminent. Better, but still hugely complex. Again, satellites don't take well to sitting around doing nothing for years on end. Remember that an emergency replacement can cost more and have a shorter life; if that's not acceptable, then it is not really an emergency. Huh? We're talking about recovering dead satellites, aren't we? That's going to require a very sophisticated satellite with rendezvous and docking/grappling capability. Such a satellite is not off-the-shelf, and will be far from cheap. Shooting down a dead satellite The US does not have that capability. The US can only shoot at such a satellite, and break it. Same difference. The US has the capability to render the satellite harmless. That's all we need. Brian |
#42
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Moscow...we have a problem.
well japan had a similiar sort of main engine failure but was still
able to communicate with and command its probe. I guess they didnt design it with no communication ability in the event of engine failure...... russia not so good. design engineering and oversite failure...... |
#43
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Moscow...we have a problem.
On Nov 23, 3:51*pm, Fred J. McCall wrote:
bob haller wrote: well japan had a similiar sort of main engine failure but was still able to communicate with and command its probe. I guess they didnt design it with no communication ability in the event of engine failure...... russia not so good. design engineering and oversite failure...... Reality just doesn't intrude into your little private corner of the universe, does it, Bobbert? -- "Ordinarily he is insane. But he has lucid moments when he is *only stupid." * * * * * * * * * * * * * * -- Heinrich Heine fred the loon, spacecraft failures are to be expected, designing a craft with little communication ability if a engine doesnt fire is just plain dumb. they did get a bit of communication with the vehicle but no useful telemetary. so all is not totally lost |
#44
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Moscow...we have a problem.
In sci.space.history message
, Mon, 21 Nov 2011 18:14:28, Brian Thorn posted: On Sun, 20 Nov 2011 22:03:08 +0000, Dr J R Stockton wrote: Then one does not use that type of propellant; one uses a system that stores better. There are solids, hypergolics, and cryogenics. Solids we've discussed. Hypergolics are toxic and corrosive (a Titan II exploded in its silo in Arkansas). Cryogenics are difficult to store for long periods of time due to high boil-off rates. Cryogenic propellants are cheap, at ground level. They are also widely- traded commodities. They can be ordered at need, in accordance with prior arrangements. Remember that this is not the "launch in 5 minutes or else" missiles; I see it as being "launch in a few days" or thereabouts. Moreover, there is no need to use cryogenic propellant_s_. Soyuz, the most-used rocket family, uses LOX and (a superior grade of) jet fuel. Both are routinely delivered to airports world-wide. and LOX is not so very cold; a liquefier to handle the boil-off from a modestly-sized properly-built LOX farm cannot be so difficult to build and run (FYI, I've worked in a place which built its own Helium liquefier, and at other places that routinely used quantities of liquid Helium & Nitrogen.) What else is there? But I was not proposing making a few launchers and keeping them on standby for decades, as the USG wants for ICBMs. Instead, after a relatively short period of storage, each one is used for a routine launch. No rockets are standardized that way. Rockets are very expensive. The launch industry wants to get every penny and pound out of their rockets as they can, and each one is essentially custom made. A rocket built to launch a Boeing satellite can't be used to launch an Astrium satellite, at least not without a lot of modification, which defeats the purpose. One reason why rockets are very expensive is that the design is varied in that manner, in the USA. It's time the country learned better, and caught up with the late Soviets. The Federal US needs the capability to introduce a new class of launcher. It did that in the seventies (+-), with STS. It thought that it could do that with Ares and Constellation. It may be able to do that with the new SLS; but we need to wait for a year of the next Presidency to know whether to believe it. Shuttle was a failure. Ares was a failure. SLS will almost certainly be a failure. Now you want the government to try again? It is alleges that Churchill said "one can rely on America to do the right thing, ... after having exhausted all other possibilities". But I meant America as a whole should introduce such a class into US service, not that the USG should design and manufacture. TsSKB-Progress would perhaps offer reasonable terms for delivery of a shipload of Soyuz a couple of times a year, though SpaceX might be better. His system is new, and naturally things are slow, and many delays seem to be occasioned Federally. His system must obey the same laws of physics as everyone else's system. Physics, yes. But not those requiring wide distribution of pork and comfy office jobs. So far, the only organization that has shown the very high launch rates Musk insists he can meet, is the U.S.S.R. Musk doesn't have the ability to send underperformers off to the Gulag. Perhaps giving overperformers a free trip to Florida, Tahiti, or LEO will be equally effective. And, otherwise, the Capitalist Russians must have plenty of Gulags to rent out. I must insist we wait until SpaceX has actually launched more than a couple of large rockets before we declare them the be-all and end-all of space launch. Ariane V is not fast. One of their launch campaigns is still measure in months from hardware arrival at Kourou to launch. Ariane V and Atlas 5 both go to the pad fairly shortly before launch, but that's just the end of a long launch campaign. I think not. Ariane has plenty of payloads booked, Booked years in advance, with rockets custom tailored to the customer's payload. With Ariane models selected, which is not the same. But I was explaining how Ariane already has enough mission purchasers. Shooting down a dead satellite The US does not have that capability. The US can only shoot at such a satellite, and break it. Same difference. The US has the capability to render the satellite harmless. That's all we need. Except that it would be beneficial if the populace understood what is going on. I can only judge by the ordinary US press; and I don't believe that they are especially selected for stupidity in comparison with the general population. Who was it that, earlier this week, described Curiosity's power source as "fission" - VoA, I believe. The press should learn to write accurately; many readers will understand or remember, and can tell the others. -- (c) John Stockton, Surrey, UK. Turnpike v6.05 MIME. Web http://www.merlyn.demon.co.uk/ - FAQish topics, acronyms, & links. Proper = 4-line sig. separator as above, a line exactly "-- " (SonOfRFC1036) Do not Mail News to me. Before a reply, quote with "" or " " (SonOfRFC1036) |
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