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The current plan to retire the space shuttle around 2010, following
completion of the ISS, seems like it will leave the space station in a precarious state. Even assuming that we develop the "CEV" for crew transport functions, how will we make up for the loss of the shuttle's payload capability and remote manipulator system? Won't components on the space station require periodic replacement throughout the station's operational life? Examples would be the Control Moment Gyros, and perhaps things like solar arrays. Also, how will experiments be ferried to and from the station. Progress and ATV vehicles cannot return things back to Earth, and the Soyuz certainly doesn't have the required payload capability. The CEV doesn't seem likely to either. |
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vthokie wrote:
The current plan to retire the space shuttle around 2010, following completion of the ISS, seems like it will leave the space station in a precarious state. Even assuming that we develop the "CEV" for crew transport functions, how will we make up for the loss of the shuttle's payload capability and remote manipulator system? Won't components on the space station require periodic replacement throughout the station's operational life? Examples would be the Control Moment Gyros, and perhaps things like solar arrays. Also, how will experiments be ferried to and from the station. Progress and ATV vehicles cannot return things back to Earth, and the Soyuz certainly doesn't have the required payload capability. The CEV doesn't seem likely to either. the shuttle, while it is a great technological achievement, should have been replaced 20 years ago, its far too expensive to justify its use for things like station construction as for the station, a more realistic question would be "Should we continue to support the station?" To me, the answer is a definite "NO" Just think about it, the station has been cut, redesigned, scaled back, and now is deteriorating fast. In its currently planned configuration the amount of general maintenance needed to just keep it running takes so much of the crews time that little is left for science http://www.spacedaily.com/news/oped-04u.html now that the plan is to have a crew of more than 3 (3 being more likely) the maintenance mess does not look likely to be ending anytime soon http://www.space.com/missionlaunches...ew_040723.html remember the original plan for the station was to have a crew of 6+ which at least would have given some hope for some form of science return as for the CEV does anyone actually believe that will ever see the light of day? its budget has been cut http://www.spacedaily.com/news/spacetravel-04zp.html and even if Bush does manage to get the funding restored whats the chances of it surviving the next budget session (with a different president?) its doomed to follow the venturestar and so many other expensive projects that had next to zero chance of success from the outset --- Web: www.sol4.net Jabber: Block List: sol4.net/spam_blocks.shtml Powered by Apples and Penguins |
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![]() "vthokie" wrote in message om... The current plan to retire the space shuttle around 2010, following completion of the ISS, seems like it will leave the space station in a precarious state. Even assuming that we develop the "CEV" for crew transport functions, how will we make up for the loss of the shuttle's payload capability and remote manipulator system? We, the US, won't. Both ESA and Japan are working on vehicles to resupply ISS. Once the shuttle is retired, any new modules launched will surely be Russian. Resupply will be handled by Russia, ESA, and Japan. At that point, I'm guessing the international partners won't much care what the US does. In fact, if the US stopped sending astronauts to ISS, it would give ESA and Japan the opportunity to send more of their own people to ISS. Won't components on the space station require periodic replacement throughout the station's operational life? Surely, but this could be handled by having the shuttle bring up several spares before it's retired. Also, there are the Russian, ESA, and Japanese unmanned resupply vehicles. The only issues will be with pieces that need to go outside ISS and are too big to fit through the hatches on ISS. This means you'd have to mount such equipment on the outside of the unmanned resupply vehicle. Not an impossible task, but I'm not sure if any of the vehicles being currently developed have considered this possibility. Examples would be the Control Moment Gyros, and perhaps things like solar arrays. There should be enough solar arrays to compensate for failures. Worst case, the Russians can start tacking on more solar arrays like they did with Mir. Also, how will experiments be ferried to and from the station. Progress and ATV vehicles cannot return things back to Earth, and the Soyuz certainly doesn't have the required payload capability. Good question. The CEV doesn't seem likely to either. It seems more likely than Soyuz. CEV, after all, is intended to support the return to moon and Mars, so you've got to have some payload return, even if it's in a "cargo return" module without people on it. ISS would be a great place to test such a vehicle in an operational mode before sending it all the way to the moon. Jeff -- Remove icky phrase from email address to get a valid address. |
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Both ESA and Japan are working on vehicles to resupply ISS. Once the
shuttle is retired, any new modules launched will surely be Russian. Resupply will be handled by Russia, ESA, and Japan. At that point, I'm guessing the international partners won't much care what the US does. Neither the ESA nor Japan is planning a particularly robust flight rate. Russia would perhaps like to continue their flight rate but there is the issue of money. So I could see them *saying* they don't need the US, but I'm not sure they would really mean it. Also, there are the Russian, ESA, and Japanese unmanned resupply vehicles. The only issues will be with pieces that need to go outside ISS and are too big to fit through the hatches on ISS. This means you'd have to mount such equipment on the outside of the unmanned resupply vehicle. Not an impossible task, but I'm not sure if any of the vehicles being currently developed have considered this possibility. Interesting question. I had been sort of assuming that it wouldn't be all that hard to modify a Progress, ATV, or HTV to have an opening, or removable fairing/door, large enough to remove, say, a CMG, with the station's arm. But my optimism might be unfounded - there's the question of what the opening would do to the structure of the vehicle, whether the station arm can get close enough to maneuver, etc. Of course the other approach is to use something larger than the usual resupply vehicles (perhaps a module based on the Zvezda/Zarya design, for example). This one is, of course, further from being off a shelf or open production line. Also, how will experiments be ferried to and from the station. Progress and ATV vehicles cannot return things back to Earth, and the Soyuz certainly doesn't have the required payload capability. Well, the question is whether returning samples/hardware to earth is a requirement or a "nice to have". For the most part, given the cost of sample return, I'd lean towards saying it is cheaper to replace the hardware, destroy most of the samples after you have downloaded the data from them, and return a few samples here and there (e.g. Soyuz could carry a hundred or more kg, if it carries only 2 people, or even with a crew of 3 it could carry some small number of kg). Of course, these tradeoffs are rarely simple. Saying one choice is "cheaper" than the others means little if the two costs come from two different budgets and it isn't particularly feasible to trade between the two (as has been the case with shuttle vehicle versus shuttle payload budgets for the last decades, for example, or for money spent by one country versus money spent by another). |
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Jeff Findley wrote:
Surely, but this could be handled by having the shuttle bring up several spares before it's retired. Also, there are the Russian, ESA, and Japanese unmanned resupply vehicles. The only issues will be with pieces that need to go outside ISS and are too big to fit through the hatches on ISS. This means you'd have to mount such equipment on the outside of the unmanned resupply vehicle. Not an impossible task, but I'm not sure if any of the vehicles being currently developed have considered this possibility. HTV can do this. See http://www.jaxa.jp/jda/brochure/img/01/htv.pdf [1.4Mb PDF]. There should be enough solar arrays to compensate for failures. Worst case, the Russians can start tacking on more solar arrays like they did with Mir. Well, Zvezda can take a third on top, just like Mir. I think that such an installation is more likely than the addition of the SPP. It seems more likely than Soyuz. CEV, after all, is intended to support the return to moon and Mars, so you've got to have some payload return, even if it's in a "cargo return" module without people on it. ISS would be a great place to test such a vehicle in an operational mode before sending it all the way to the moon. I agree. If CEV is to be built for expeditionary missions, then I think it would be natural to test it out around the ISS. However, CEV is still a long way from flying, and given recent history, far more likely to be cancelled than to ever get off the ground. Bring back the X-38 derived CRV, I say. --Chris |
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![]() "Chris Bennetts" wrote in message ... Jeff Findley wrote: Surely, but this could be handled by having the shuttle bring up several spares before it's retired. Also, there are the Russian, ESA, and Japanese unmanned resupply vehicles. The only issues will be with pieces that need to go outside ISS and are too big to fit through the hatches on ISS. This means you'd have to mount such equipment on the outside of the unmanned resupply vehicle. Not an impossible task, but I'm not sure if any of the vehicles being currently developed have considered this possibility. HTV can do this. See http://www.jaxa.jp/jda/brochure/img/01/htv.pdf [1.4Mb PDF]. Thanks for the link. From the picture, it looks like HTV has a large, unpressurized area. The document says: HTV has 2 types of logistics carrier: pressurized section where crewmembers can work when HTV is being berthed to the ISS; and unpressurized section that accommodates Kibo's Exposed Facility payloads on Exposed Pallet. In addition to the U.S. Space Shuttle and Japan's HTV, Russian Progress and ESA's ATV also serve as ISS cargo spacecraft. However, HTV is the only vehicle to deliver materials used onboard the ISS and through EVAs. So HTV would appear to be the (non-shuttle) vehicle most likely to be able to deliver something like a CMG to ISS. I'm sure the details would need examined (like size and weight of the CMG). Jeff -- Remove icky phrase from email address to get a valid address. |
#7
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Next time, I.S.S. 2 or what ever its name will be should be build like
Mir. Jim Kingdon wrote in message ... Neither the ESA nor Japan is planning a particularly robust flight rate. Correct. Russia would perhaps like to continue their flight rate but there is the issue of money. Well... The same thing probably be can said about N.A.S.A. (U.S.A.), after the Space Shuttles were retired, will N.A.S.A. got the enough money? So I could see them *saying* they don't need the US, but I'm not sure they would really mean it. The Russian sure can said that they don't need the U.S.A. government, considering there's no way that the U.S.A. government will pay for the Russian space programs. Though obviously that the Russian no longer have control of their own space program, considering that they can be ordered to bring down Mir and then claimed that it was done with their own will. E.S.A. (Europe) and N.A.S.D.A (Japan) on the other hand are quite dependant on N.A.S.A. for manned spaceflight. Betcha that any future space station probably will done by the 'private' industry without any participation from any current government in the world. Of course the other approach is to use something larger than the usual resupply vehicles (perhaps a module based on the Zvezda/Zarya design, for example). This one is, of course, further from being off a shelf or open production line. Well.. There's the Progress M2, but design on it was left off considering that it was planned to be used with the Zenit launch vehicle. But I guess that's up to the 'private' industry to marry the Progress M2 with the Zenit. Well, the question is whether returning samples/hardware to earth is a requirement or a "nice to have". Considering that many of the experiments conducted are probably secret experiments labeled as something else, we really don't know on what kind of samples they need to bring down. Due the nature of their secrecy, the amount of the most important samples that need to bring back are probably in small size, probably big enough to be bring down using the Soyuz. |
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On 2004-07-31, EAC wrote:
Next time, I.S.S. 2 or what ever its name will be should be build like Mir. Jim Kingdon wrote in message ... Neither the ESA nor Japan is planning a particularly robust flight rate. Correct. Russia would perhaps like to continue their flight rate but there is the issue of money. Well... The same thing probably be can said about N.A.S.A. (U.S.A.), after the Space Shuttles were retired, will N.A.S.A. got the enough money? So I could see them *saying* they don't need the US, but I'm not sure they would really mean it. The Russian sure can said that they don't need the U.S.A. government, considering there's no way that the U.S.A. government will pay for the Russian space programs. Though obviously that the Russian no longer have control of their own space program, considering that they can be ordered to bring down Mir and then claimed that it was done with their own will. E.S.A. (Europe) and N.A.S.D.A (Japan) on the other hand are quite dependant on N.A.S.A. for manned spaceflight. The last Soyuz flew with an ESA crewmember, and this arrangement has been not uncommon of late. (Both are perfectly capable of developing a manned taxi re-entry vehicle, with an indigenous launch capacity suficient to support it. They've not made notable moves towards this - Hermes was cancelled about the time ISS in its current incarnation was decided upon - but the technical capacity is certainly there if the political will is...) Betcha that any future space station probably will done by the 'private' industry without any participation from any current government in the world. There is China, remember; stated and perfectly credible plans are to build a small space station, possibly utilizing Shenzou service modules, in the medium-term future. China is a lot more open than it was ten years ago, but I doubt it'll be a private business. Well, the question is whether returning samples/hardware to earth is a requirement or a "nice to have". Considering that many of the experiments conducted are probably secret experiments labeled as something else, we really don't know on what kind of samples they need to bring down. Due the nature of their secrecy, the amount of the most important samples that need to bring back are probably in small size, probably big enough to be bring down using the Soyuz. Hmm. So, you've theorised a previously unknown covert research operation, and used that to extrapolate downmass requirements. I am cynical... (If nothing else, a population of heavily ex-military people from both sides, plus random foreign passers-through, would seem to be militating against any effective secrecy) Let's take a sample flight: STS-113, the last pre-Columbia flight, brought back: "Experiments (...) including protein crystals and zeolite samples." "The Power Distribution and Conversion (PDC) box and one of the Exchangeable Standard Electronic Modules (ESEM3) were removed from the Microgravity Science Glovebox on-orbit and brought back on STS-113." (for repair and relaunch) http://google.com/groups?selm=FtFK9....0.che llo.com "FE-1/SO Peggy Whitson and Lopez-Alegria removed the PCG-STES007 (protein crystal growth-single locker thermal enclosure system #7) payload from EXPRESS rack 4 (ER4) and installed and powered it on in the Shuttle middeck." "Exp. 6 FE-2 Don Pettit is scheduled to transfer the PGBA (plant generic bioprocessing apparatus) and the PGBA mufflers from the ISS to the Orbiter middeck." "Exp. 5 CDR Valery Korzun removed the European GCF-B (Granada Crystallization Facility B) from its stowage location in the DC-1 module and transferred it, stored in the ARCTIC2 unit, to the Shuttle for return to Earth." http://google.com/groups?selm=tE%25G...0.c hello.com "Approximately 2,203 pounds of equipment and experiments from the International Space Station will also return home aboard Endeavour." http://google.com/groups?selm=q3lH9....0.che llo.com -- -Andrew Gray |
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