"International Partners" means the Russians who launch manned missions from 51 north at present. If encouraged [ie funded] they could launch manned missions from Kourou. They have been building this capability for some time now. As for the Japanese, Tanegashima is at 30 degrees north. Chinese Xichang is at 27 deg 57' N. and Jiuquan is at 40 deg 57' N.The point is, if VASIMR works for ISS orbit raising, it could also work for orbit inclination change.As with all ideas, it is only possible when people decide it can be done. If there is only support for status quo and the advantages of other possible scenarios can not be visualized, then the idea is "impossible" a priori. The stated reasons that make this idea 'impossible' are all political, and not based on physics.New ideas start with "what if...?" Sadly, I think most Americans have forgotten how to ask this question.
We want the same "encouragement" as the Russians.
Yes, the question is, how would this change the overall architecture, what would be the net cost pluses and minuses of an ISS in 30 degree inclination orbit wrt outward bound exploration, assuming full international cooperation? It could be a depot for fuels and other consumables, in-space construction 'dry-dock' for assembly of large vehicles, return decontamination and rest before return to Earth...of what value is a large, semi-permanent, multifunctional outpost in this location to incoming and outgoing traffic? ...versus having nothing there.
Quote from: Integrator on 10/12/2009 03:12 pmYes, the question is, how would this change the overall architecture, what would be the net cost pluses and minuses of an ISS in 30 degree inclination orbit wrt outward bound exploration, assuming full international cooperation? It could be a depot for fuels and other consumables, in-space construction 'dry-dock' for assembly of large vehicles, return decontamination and rest before return to Earth...of what value is a large, semi-permanent, multifunctional outpost in this location to incoming and outgoing traffic? ...versus having nothing there.VASIMR could be a good way to change the orbit of the ISS. But all the things you say can be done - and should but likely won't - from its current orbit. What's the urgency to move ISS?
Von Braun has a line in "The Mars Project" pointing out a space station is any orbit is not important to his fleet, because even if you assemble it at one, you won't be able to return to it, due to the realities of orbital mechanics. But if you've got a little extra delta-v, that's not so.
Quote from: Integrator on 10/12/2009 11:02 amWho said anything about orbit beyond LEO? We are just discussing using VASMIR to change the orbit inclination and maintain altitude margin.The orbital inclination of the ISS won't be changed.
Who said anything about orbit beyond LEO? We are just discussing using VASMIR to change the orbit inclination and maintain altitude margin.
It's a non-started out of a multitude of reasons, most notably international partners being fundamentally against it.
It's an odd discussion anyway, considering this is a VASIMR thread and when (or better if) VASIMR is ultimately flown to the ISS and used as an experiment (!) is totally up in the air.
Quote from: William Barton on 10/12/2009 04:24 pmVon Braun has a line in "The Mars Project" pointing out a space station is any orbit is not important to his fleet, because even if you assemble it at one, you won't be able to return to it, due to the realities of orbital mechanics. But if you've got a little extra delta-v, that's not so.Or higher Isp, or aerobraking or a higher energy orbit. Propulsive braking back to a Lagrange point is perfectly possible - even with ... tadadada ... hypergolics.
I think Von Braun was thinking of very low Isp hypergolics (in the middle 200s). His 3-stage shuttles were 4x the size of Saturn V for a 20mT payload (iirc) and the fleet was going to take 900 launches to assemble!
The other question is whether it matters enough to bother, at whatever cost.
Aren't the launch windows for the Moon much more important to chemical propulsion than something like VASIMR?
But he was assuming using hypergolics from LEO, wasn't he? Nowadays we could use cryogenic propulsion from LEO to L1/L2, and hypergolics only from L1/L2 to Earth swingby through TMI. And we could preposition propellant using electric propulsion, initially SEP but later on maybe VASIMR.The idea of returning to a space station is perfectly possible. LEO would be more difficult than L1/L2, but not impossible with VASIMR or aerobraking. On the other hand, you don't really need a whole station, a depot or even just a refuelable transfer vehicle acting as a depot would be good enough. On the other hand, if you have one anyway, why not use it? It seems more useful on the outbound leg than on the inbound leg though.But why oh why do we need to change the orbit of the ISS for that?
VASIMR could be an excellent way of doing it but I haven't heard an explanation why the orbit needs to be changed.
It looks like a solution in search of a problem.
I'm all for finding initial applications for VASIMR, especially VASIMR on the ISS, but I don't think changing the inclination of the orbit of the ISS is that application.
Why not just use VASIMR to reboost its orbit periodically?
If we change the ISS's orbit to same inclination as the moon have you don't have to wait for ca. 2 weeks to get a new window. This means increased flexibility for missions.
Nodal regression will rotate your orbit plane out of moon plane.
Quote from: William Barton on 10/12/2009 04:24 pmThe other question is whether it matters enough to bother, at whatever cost. Almost nothing is for free but all consumables are on the ISS for free and could at least cheap produced there. Unused Hydrogen gets blown into space. That could get the fuel for VF-200. If you realize a cascade with the existing cooling aggregates you can perhaps produce the coolant for the superconductors of VF-200. At least oxygen is liquefiable at nitrogen is close.Quote from: William Barton on 10/12/2009 04:24 pmAren't the launch windows for the Moon much more important to chemical propulsion than something like VASIMR?Do you mean using VASIMR between earth and moon? Excellent idea! But why drop every time a spacecraft that can get cheap refueled? To keep such a spacecraft in orbit would get much easier if you have an orbital spaceport in LEO.Quote from: William Barton on 10/12/2009 04:24 pmVon Braun has a line in "The Mars Project" pointing out a space station is any orbit is not important to his fleet, because even if you assemble it at one, you won't be able to return to it, due to the realities of orbital mechanics. But if you've got a little extra delta-v, that's not so.Well, the technology that Von Braun did thought about was totally based on chemical drives. His thoughts are therefore often outdated and in this case it's obviously outdated. It's anyway curious to argue in a VASIMR-thread against a space station in a (more) equatorial orbit with an architecture that is totally based on chemical drives.I think Jules Verne space cannon also won't have any advantage by a space station.
"International Partners" means the Russians who launch manned missions from 51 north at present. If encouraged [ie funded] they could launch manned missions from Kourou. They have been building this capability for some time now.
As for the Japanese, Tanegashima is at 30 degrees north.
Chinese Xichang is...
Exactly. Which incidentally is part of why L1/L2 are much better staging points. But the idea of using ISS as a staging point is a very good one, more so on the outward journey than on the return journey and more so with smaller launchers than with HLV. It can be done from the current orbit of the ISS, it could be done from a lower inclination. VASIMR is a good idea. ISS staging is a good idea.
Current ISS orbit and lower inclination orbits are all fine. VASIMR might be a good way to move the ISS should we want to. The international partners seem to prefer the current orbit. But the bigger point is the ISS is under enormous threat from SDLV, though fortunately not in the short term.
On the other hand and unfortunately action may have to be taken soon to make sure ISS has a future beyond 2020. ISS staging makes much less sense with HLV and heavy upper stages. SDLV consumes so much money there will not be an ISS after 2020 if there is an SDLV unless NASA gets more money. Quote from: mmeijeri on 10/12/2009 06:31 pmDid read about 20% more budget are intended. ISS is an excellent proving ground for VASIMR, but also for things like automated docking and rendezvous, bioregenerative life support systems etc. It is also a potential anchor customer for commercial manned spaceflight. Making sure ISS continues to exist at all is much more important than changing its orbit.
Did read about 20% more budget are intended.
Quote from: SpaceWarper on 10/12/2009 05:45 pmQuote from: William Barton on 10/12/2009 04:24 pmThe other question is whether it matters enough to bother, at whatever cost. Almost nothing is for free but all consumables are on the ISS for free and could at least cheap produced there. Unused Hydrogen gets blown into space. That could get the fuel for VF-200. If you realize a cascade with the existing cooling aggregates you can perhaps produce the coolant for the superconductors of VF-200. At least oxygen is liquefiable at nitrogen is close.Quote from: William Barton on 10/12/2009 04:24 pmAren't the launch windows for the Moon much more important to chemical propulsion than something like VASIMR?Do you mean using VASIMR between earth and moon? Excellent idea! But why drop every time a spacecraft that can get cheap refueled? To keep such a spacecraft in orbit would get much easier if you have an orbital spaceport in LEO.Quote from: William Barton on 10/12/2009 04:24 pmWhat I had in mind when I mentioned it was a VASIMR tug between ISS (where it is) and LLO (or L1/2). Obvious a VASIMR tug would be reusable. I did find thoughts about powering five VF-200 with 1MW. Therein is a lot to interprete.Quote from: William Barton on 10/12/2009 04:24 pmWhat's being ignored is, it will cost money to move ISS. Is it worth it, or would the money be better spent elsewise? Lets no forget VASIMR isn't a fuelless space drive! Fuel is for free if you take the hydrogen from their oxygen-generator that produce oxygen from water and they blow into space. VF-200 can work with hydrogen. I didn't find any significant necessary consumable that isn't there for free or can't get produced there. Therefore i think it's almost for free.
Quote from: William Barton on 10/12/2009 04:24 pmThe other question is whether it matters enough to bother, at whatever cost. Almost nothing is for free but all consumables are on the ISS for free and could at least cheap produced there. Unused Hydrogen gets blown into space. That could get the fuel for VF-200. If you realize a cascade with the existing cooling aggregates you can perhaps produce the coolant for the superconductors of VF-200. At least oxygen is liquefiable at nitrogen is close.Quote from: William Barton on 10/12/2009 04:24 pmAren't the launch windows for the Moon much more important to chemical propulsion than something like VASIMR?Do you mean using VASIMR between earth and moon? Excellent idea! But why drop every time a spacecraft that can get cheap refueled? To keep such a spacecraft in orbit would get much easier if you have an orbital spaceport in LEO.Quote from: William Barton on 10/12/2009 04:24 pmWhat I had in mind when I mentioned it was a VASIMR tug between ISS (where it is) and LLO (or L1/2). Obvious a VASIMR tug would be reusable. I did find thoughts about powering five VF-200 with 1MW. Therein is a lot to interprete.Quote from: William Barton on 10/12/2009 04:24 pmWhat's being ignored is, it will cost money to move ISS. Is it worth it, or would the money be better spent elsewise? Lets no forget VASIMR isn't a fuelless space drive! Fuel is for free if you take the hydrogen from their oxygen-generator that produce oxygen from water and they blow into space. VF-200 can work with hydrogen. I didn't find any significant necessary consumable that isn't there for free or can't get produced there. Therefore i think it's almost for free.
What I had in mind when I mentioned it was a VASIMR tug between ISS (where it is) and LLO (or L1/2). Obvious a VASIMR tug would be reusable.
What's being ignored is, it will cost money to move ISS. Is it worth it, or would the money be better spent elsewise? Lets no forget VASIMR isn't a fuelless space drive!
It doesn't make any sense to me to burn your house to buy a new car.
Quote from: SpaceWarper on 10/12/2009 08:04 pmIt doesn't make any sense to me to burn your house to buy a new car.House = ISS and car = SDLV? If so, we agree.
maybe if they use heavy xenon and not h2 vasimr engine will have greater performance?why not carry some noble heavy gas to iss, to test the true potencial of vasimr?
Once the VASIMR system is delivered where would it be placed on the station? On top of Z1?