#861
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Les (Friendly Airplane Asylum & ex-NASA flack) |
#862
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Will I be doing those additions for Venus Express? Maybe, if I find the time someday.
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Currently designing: add-ons for ESA's Mars Express paper model |
#863
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Never mind... Got my answer
Last edited by MECO; 07-10-2012 at 08:32 AM. |
#864
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You may already know about this resource, but whilst looking for something else I saw this 27.64 MB 'International Space Station Overview' PDF on the NASA website, amongst Press Kits and similar stuff. A lot of detail that may be of interest to ISS model builders:
http://www.nasa.gov/pdf/508318main_I...de_nov2010.pdf |
#865
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Wow, it's been a LONG time since I've worked on my ISS. Thinking about getting back to it......
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Mohammed Aly Current Projects LUT, Pad 39A |
#866
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that's a nice link there, thanks for the heads up!
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#867
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on the topic of the ISS (but off topic re paper models)....
I pose a question to you that are more knowledgeable than me: Just heard about the plan to scuttle the ISS in a few years. Apparently it will be crashed into the Pacific, since it cannot be left as orbiting "debris". This I understand. But why scuttle it? Why crash it to earth? Why not add a couple of cameras? Throw in some outdated electronics and give it the ability to send a photo or data back to earth every now and then. Then give it a nudge out into Space and send it on its way. Its already up there...why not use it for something else? Or put it into orbit around the Moon? Turn it into an orbiting Moon platform. Crash it into the Sun...to see how close it gets. Have it take photos and send back data right up to the point of incineration? Imagine the closeup views of the Sun we could get! I am fully aware of the reasons not to salvage it...salvage costs quite often outweigh the values. I guess I am just having a big problem with the idea of just crashing it into the Ocean and throwing it away so easily.
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SUPPORT ME PLEASE: PaperModelShop Or, my models at ecardmodels: Dave'sCardCreations |
#868
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I guess the short answer is money.
The ISS is so heavy that you had to spend an incredible amount of fuel to kick it into anything else than an earth orbit. If you just want cameras flying somewhere, you don't need so many tons of unneccessary man-rated modules. That's why we build unmanned spacecraft, they are small and light to take the maximum velocity from the limited amount of fuel. |
#869
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Dave, all this has been discussed over at NASASpaceFlight.com check out the forum there.
I agree with you, tossing/crashing/burning up 100 Billion dollers of nice shiny equipment is crazy. Personally I think it will get another extension, living beyond 2030. |
#870
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ISS weighs several hundred tons... and it's the size of a football field. That means that it would be very difficult to do more than the periodic reboosts on it that continually raise its orbit from time to time to prevent it from reentering naturally over time. If ISS were merely "abandoned in place" and left in orbit, much like Skylab was, then its orbit would eventually decay due to its enormous size and the very slight but measurable drag it experiences from Earth's outer atmosphere... and it would re-enter in an uncontrolled fashion, just like Skylab. Skylab, due to its size, survived long enough during reentry to rain debris across a wide area, thankfully in a remote area of Australia and at sea. ISS, being larger, would be just as likely if not more so, were it to reenter in an uncontrolled fashion. Remember the brouhaha over the shootdown of the large spysat a couple years ago?? While it's likely the Air Force didn't want any "sensitive parts" coming down where they could potentially be salvaged and studied by unfriendly intelligence services around the world, the official reason was that the satellite was carrying a large quantity of hydrazine propellants, which are highly toxic, and could potentially contaminate a large area or even poison people on the ground were it to impact in a metropolitan area... and some of the components (like mirrors and such) were of such a mass and material it was likely they would survive reentry in such a fashion as to pose a hazard to people on the ground should they impact nearby. ISS poses a similar hazard. Therefore, when ISS IS "decommissioned", it will eventually be sent on a targeted reentry somewhere over the Pacific ocean, where any surviving pieces in its "debris footprint" will fall harmlessly (hopefully, but statistically so) into the ocean and sink. Quote:
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The other issue is, if you're sending it to one of the Lagrange points, say L1 or L2 between Earth and Moon, (EML1 or EML2 behind the moon) then you have to decelerate it into a halo orbit at the L points... and keep it there. Or, if you're sending it to Low Lunar Orbit (LLO) you have to decelerate it into LLO, and provide reboost propellant on an ongoing basis to account for lunar mascons degrading the orbit. HLO might be better from this point of view, but again, the thermal issues will be considerable. Accelerating and decelerating such a MASSIVE object creates a WHOLE lot of headaches... it just isn't worth the effort. Nothing remotely the size of ISS will be needed in LLO or EML1 or 2 for many many decades, if ever... by which point ISS will be as antiquated as the Wright Flyer... Quote:
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When ISS eventually is decommissioned, it will be decrewed and put in a standby power-down mode. The propulsion, guidance, stabilization, and communications telemetry systems will have all been put in top working order to facilitate the eventual deorbit. Once the crew has left, the station will be left to orbit, as it's orbit will naturally and predictably decay due to the continual miniscule air drag that it encounters from Earth's outer atmosphere (which will eventually get Hubble too, BTW-- Hubble has no ability to boost it's own orbit, unlike ISS via its Russian Service Module or a visiting Progress cargo ship). Without reboosts, ISS's orbit will gradually decay until it's near an uncontrolled reentry. At some point, a deliberate manuever will put the service module flying backwards to the orbital direction, to provide retrograde thrust. The SM will be commanded to burn its reboost rockets in retrofire mode to lower its orbit to intersect Earth's atmosphere at the desired entry point, to put the debris footprint and impact points of any surviving bits into an unpopulated part of the ocean... Just as was done for Mir, so will ISS follow... Later! OL JR
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The X-87B Cruise Basselope-- THE ultimate weapon in the arsenal of Homeland Defence and only $52 million per round! |
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