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How typical, trying to re-write history... essentially all the intelligence agencies of free countries in the world all believed that Saddam did indeed have weapons programs... and France/Germany/et al. are supposed to ignore their own intelligence for "an individual... stated he works for the CIA and that the CIA found "no compelling evidence of any weapons of mass destruction in Iraq." The Russians even publicly, though quietly, assured that Saddam had such programs. The fact that neither France/Germany/Russia decided to even lend moral support was because of their windfall from dealing with Saddam (both economically and influence peddaling)... after all, Saddam would only gas Americans, Britons, and Israelis, so what did they care? Saddam also had a full year and an completly unmonitored, unobstructed border with its friend Syria. Saddam also had hundreds of tons of pesticide in in bunkers... now why would he do that?
Canada also did side with the corrupt, insufferable, obstructionist, appeasnik French and Germans concerning the just and nessesarry mission in Iraq. Saddam also did beyond any shadow of doubt help terrorists and was obviously even more a part of the war on terror than Afghanistan, but that didn't seem to sway our friends to the North. He even sent "reward" money to "Palestinian" suicide bombers' relatives! The idea that he was not a problem and would behave is utterly naieve and completly undefendable, especially since Saddam believed WMDs were his "insurance policy," and Canada wouldn't even publicly stand with us? Getting rid of Saddam was the right thing to do, and Canada wouldn't lend its voice when it was needed most.
And lets not forget the insult of rejecting radar sites for the ballistic missile interceptors even though NORAD has had sites in country for years... Paul Martin even demanded we ask first before trying to stop hypersonic ballistic missiles only moments from impact! Keeping troops in Afghanistan and not hanging the US Navy out to dry on the eve of war against Saddam is commendable, but frankly is something I expect... Canada's survival is dependant on victory against terrorism too.
And why shouldn't we ask that NATO units be under ultimate American control? This isn't Gulf War-I, basically a big excercise in air power and Blitzcreig, and only America has the ability to airlift any large number of troops. There has to be only one command for an operation like Iraqi Freedom, command by comittee - especially when things might become politically contentious - would simply not work this time. Since we're providing the ride, much of the logistics, and the bulk of the forces anyway, we were well justified asking our "allies" to fight under our command.
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But besides that, friends don't ask friends to jump off cliffs for them, particularly when they have essentially nothing to gain from it. The Canadians won't gain much from the ISS either, the science that could be done there has always been a flimsy cover for being an aerospace make-work project, and nobody really cares much about who the astronauts are onboard. The Canadian space program would be right back where it started pre-ISS days.
The US, unlike Canada, has much more to lose in the project, that the massive burden of the ISS threatens to cripple the only long-term project that has the political impetuous to suceed, the VSE. When the ISS inevitibly is retired, NASA must have built sufficent inertia with VSE that NASA would not be quietly closed by an obscure line in a Congressional budget. And for what? Next to nothing.
What we could do, if we are feeling generous, is of course bring some Canadians with us when we get back in the business of going places. Drop the nonsense about ISS science racks and petty robot arms that are already built and sign on to make scientific gear for VSE to compensate. Canadians on the ISS? Boring... Canadains on the Moon though...
Shooting our space program in both legs and making it crawl to the Moon on pain of death is not what I would consider "working with industrial countries rather than offending them," given how little they have to gain, its us who they're offending.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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But besides that, friends don't ask friends to jump off cliffs for them...
Shooting our space program in both legs and making it crawl to the Moon on pain of death is not what I would consider "working with industrial countries rather than offending them," given how little they have to gain, its us who they're offending.
::applause::
I couldn't agree more.
--Cindy
We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...
--John Sladek (The New Apocrypha)
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Completing ISS is not "jumping off a cliff". The longer you argue, the longer you delay, the longer it will take to complete the task. It's time to shut up and get to work. You really do remind me of a child trying to get out of his chores.
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No, it's George W. and his advisers who are trying to rewrite history. Reality is Canada, France, and Germany said give the UN inspectors a chance to do their job and believe what they found. They did look, they found a chemical weapons factory bombed to rubble, they found a dozen old chemical deployment cannon shells covered in dust but nothing to put in them, they found a uranium mine but nothing to make nuclear bombs. Face it, the Gulf War of 1991 succeeded. When General Norman Schwarzkopf said the war was over it was time to go home, that meant the war was over it was time to go home.
Osama bin Laden offered to help fight Saddam Hussein in the Persian Gulf War. No, they didn't cooperate. Osama wants to convert the entire Arab world to Islamic fundamentalism, Iraq was a secular country. There's more terrorist training in Iraq now after the war than there was before. Iraq and Al Qaeda are completely separate; contrary to any rhetoric you may have heard from George W. Bush, they are not the same thing. Did Iraq support actions in Palestine? Possibly. That again is completely separate. The Israel/Palestinian issue is long and complex with a lot of bad things on both sides. It has nothing to do with an attack on American soil.
Don't complain about Canada "not standing with us". Canada had warned the US that an invasion of Iraq now could not be justified, would undermine the UN, and would result in exactly what has happened. It's not revisionist history to say Canada and France predicted the war would turn out this way, and did warn US officials.
You want NATO to be under "ultimate US control"!? The North Atlantic Treaty Organization is a military alliance of equals. It's an alliance of nations to stand together, protecting themselves by protecting each other. The point is to fight against any foreign nation attempting to conquer or assert control over them. You are suggesting the US assert control over them; that would make the US into the enemy that every nation is fighting against. Do you really not understand the concepts of freedom and liberty?
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Back to space. Yea, there are a lot of Canadians who would like to see a Canadian astronaut on Mars. The Moon is boring; been there done that. I wish I kept the image from one joke email that was going around when Spirit landed. Pepsi showed an ad depicting a controller at JSC pausing for a second to take a drink, big bugs on Mars stripped Sprit and left it on concrete blocks. The email came out after that. It was one of the Mars images from Spirit but someone added a sign that said "Tim Horton's coming soon" and an empty Molson Canadian beer bottle half buried in the soil. For those who don't know, Tim Horton's is a Canadian coffee shop. Somehow their marketing guys have managed to convince Canadians that it's a Canadian icon.
Again I have to come back to the simple realization of completing the ISS. Remember I'm the one who argued for developing a heavy lift SDV quickly and using that to lift station modules. I'm the one who came up with the idea of a combination mission, launching 5 loads of modules at a time on SDV and keeping the engine pod attached long enough to stabilize it. Then launch a shuttle orbiter from the other launch pad with 1 load of modules and use the shuttle to pluck off modules from SDV's cargo pallet and install them. Complete ISS with 3 such combination flights, 1 additional flight first to certify the Shuttle is ready (what was going to be Atlantis' flight, now Discovery will do that one). Somewhere in there service Hubble with another flight. They fly 2 more Shuttle orbiter missions to deliver Node 3 and the US Habitation module. That's a total of 7 flights including Hubble; much less than the 15 that NASA is currently talking about, and without reducing the station at all.
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Again I have to come back to the simple realization of completing the ISS. Remember I'm the one who argued for developing a heavy lift SDV quickly and using that to lift station modules. I'm the one who came up with the idea of a combination mission, launching 5 loads of modules at a time on SDV and keeping the engine pod attached long enough to stabilize it. Then launch a shuttle orbiter from the other launch pad with 1 load of modules and use the shuttle to pluck off modules from SDV's cargo pallet and install them. Complete ISS with 3 such combination flights, 1 additional flight first to certify the Shuttle is ready (what was going to be Atlantis' flight, now Discovery will do that one). Somewhere in there service Hubble with another flight. They fly 2 more Shuttle orbiter missions to deliver Node 3 and the US Habitation module. That's a total of 7 flights including Hubble; much less than the 15 that NASA is currently talking about, and without reducing the station at all.
Though it looks good from the stand point of getting the station done and having a slightly different HLLV for moon and mars to use it does give the shuttle army something to do besides set on there rump...
As for it being a cost saving to do, this it probably would not be since the cost would be obsorbed in the developement by the contractors. Rather than the contractors eating up all the funds you would think they could do there job for less..
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RobertDyck you are right about many things, if only GCNR knew 1/10 as much about politics/relations as rockets. But he does know space, extremely well, and ISS *is* a relative waste of upwards of $100B that could be spent better otherwise, and reallocating even a fraction of that money could accelerate by years more important programs: CEV, SDV, or almost anything would be better. For example instead of your 3 SDV/shuttle combo-launches, 3 SDV launches (or even 2 or 1!) could put up a *whole new* station comparable to ISS! Little or no idiotic construction, no risked shuttle astronaut lives, far less costly, and it wouldn't be "out of warranty" by first use..
The international partners could forgive the US for bailing, and can still use the "half station," and should take part in the return to moon/mars...and perhaps a sensible station as well, if that ever seems necessary and worthwhile.
I'd rather see ISS retired than shuttle (like thats gonna happen) -ISS is a huge waste, a flying junkpile, and a bottomless money sinkhole, and will do almost nothing especially if the centrifuge module never goes up. But Griffin is pretty sharp and things are looking better and better.
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Thats a lie, Bush based his decision on the same intelligence conclusion as the rest of the world's spy agencies, who all generally agreed that Saddam had an active WMD program. Bill Clinton thought he had them... The UN inspectors were a joke, the Iraqi intelligence apparatus ran circles around them, and in a country as big as Iraq, hiding a few dozen tractor trailer loads of equipment (in Syria?) would be trivial... and why did Saddam put dozens of tons of pesticide in concrete bunkers? The biggest reason though, is that Saddam had a faith, and some say a fixation, on having such weapons as insurance against invasion by his neighbors.
Congressional reports have enumerated multiple contacts between Saddam and known terrorists, including one of top officals of one of Saddam's secret services meeting with Bin Laden's henchmen, and Ansar al-Islam has been openly based and trained in Iraq for years. It is also highly probable that money and explosives training was provided by Saddam to terrorists too. Bin Laden and Saddam may not have liked eachother, but they hated the West more then eachother.
The insinuation that terrorism born of radical Islamism is a localized, national phenominon is clearly and obviously a lie too. Terrorists in "Palestine" (aka Egypt, trans-Jordan, southern Lebanon, etc), terrorists in Indonesia, terrorists in Iran, terrorists in Saudi Arabia, terrorists in the UK, terrorists in America, and terrorists in Canada are all part of the same problem. Al Qaeda now is just a figure head, and the best way to defeat them is to show them the futility of their struggle and see to it that they are the ones who will fail in Iraq.
Another one of the many lies perpetuated by the media is that Bush's sole, lone reason for invading was WMDs or WMD programs. That is flatly, factually untrue; back in his public speeches leading up to the war, Bush also justified invading Iraq to save its people from oppression and to establish a free state. He said that, and pretending he didn't doesn't make it untrue... Bill Clinton thought it was a good idea, enough to make "regieme change" an offical national policy. Even without WMDs, getting rid of Saddam and establishing a democracy there was well worth every penny and drop of blood.
As far as NATO, that depends on the situation: in the case of a large war far from Europe like in Iraq, America is the only country capable of projecting power of the nessesarry scale, distance, and duration. Thus, since we will be taking the lead for no other reason then we are the only ones with the capability, it makes sense to unify command under us. Even British troops needed some US airlift... For police actions in the former Yugoslavia or security in Afghanistan, the scale and distance of those operations are different, in which case unified command might not be nessesarry. Its nothing personal, its purely pragmatic. Freedom and liberty, by the way, don't apply to the military chain of command: as the saying goes, the military is there to defend democracy, not practice it.
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And AGAIN I affirm that we should cancel the rest of the ISS missions and sign the pice of junk over to the Russians. Neither Russia nor Canada nor anyone else has cause to expect us to do this thing because it fantastic cost is almost entirely on our shoulders and really does threaten NASA's future. NASA is going to spend at the very least some ~$35Bn more on the station canceling Shuttle now, probobly closer to $50-60Bn with Shuttle.
Assuming a budget of about $9Bn anually until 2018, thats only $100Bn from 2006 to the 2017 ISS mission end date, then continued ISS involvement will consume about half of NASA's budget, the majority of that cost in the crucial earlier years of VSE. I don't think anyone can truthfully say, which M. Griffin has already stated, that the continued work on ISS is a threat to the viability of VSE. And without VSE, NASA has no future. NASA is being expected to do more than Apollo for only one quarter the money... that will barely be enough to get there probobly, much less think Mars any time soon.
Think about that... if roles were reversed, and America was demanding that Canada cough up $59,300,000,000.00CDN and risk the lives of several dozen astronauts for something that is the next best thing to totally useless, which we wouldn't get anything useful out of it either, it wouldn't matter what promises were made, Canada would be well justified pulling the plug. The total cost of the station to the US taxpayer will amount to about $170,000,000,000.00CDN, and we are going to get almost nothing useful out of it... Such a waste is beyond the demand of any foreign power reguardless.
"Quickly developing" any HLLV is not going to happen, not while Shuttle and ISS are still going and CEV/CLV are being developed, and infact under the current NASA budget HLLV development will be basically differd until after the 2010 Shuttle end date, when that money will be freed up. NASA also plans to close one of the two launch pads indefinatly, and if the Shuttle "chaser" mission is delayed again then the ISS modules are history. The only practical options are to eliminate Shuttle and build a high-performance tug for HLLV which will save ~$10Bn but risk cutting years off ISS life, or trudge on with Shuttle and rush over that cliff now.
Its not "childish" to not do something stupid that you said you would do if neither party will get anything out of doing that thing, which is the case today with the ISS. Even if the station is completed, it will be an old, dangerous, useless and decreipt hulk that even Canada won't get much out of it. Too much money has been and will be spent on the station to justify any bennefit it could possibly yeild, and thus we should kill the station.
Yes! Lets hurry up and get back to work! ...Digging a grave so Canada and friends can push NASA in...
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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But Griffin is pretty sharp and things are looking better and better.
Yup. IMHO, at least.
An immediate ISS / STS termination decision is above Griffin's pay grade. Only the big guy, GWB, can authorize that and he won't for a whole basket of reasons having little to do with effectual space policy.
Thus, the argument is moot. (Not that I don't sometimes enjoy rattling the cages even in a good, moot argument.)
Griffin, however, has designed a CEV+CLV that:
(a) preserves the HLLV industrial base;
(b) can service ISS if necessary (not ideally);
(c) can travel to/from the Moon; &
(d) would be non-competitive to either SpaceDev or t/Space =IF= either company manage to fly a human rated space craft.
ESAS and CEV+CLV creates a HUGE niche for NewSpace or alt-space if they can fill it (ISS crew rotation) yet does not place the VSE in jeopardy if alt-space drops the ball.
Who can ask for more?
(Well okay, back in January 2004, President Bush could have grounded STS and gave ISS to Putin and called in Condi Rice to mend fences - - I even argued for exactly that 18 months ago right here at NewMars - - but its water over the dam, now.)
Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]
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I don't think that its quite that way Bill, the spiraling cost and indeterminate delays with Shuttle really do question the viability of flying it, or at least flying it as much as planned, to finish the station. As the cost and risk spiral higher still plus the rapidly declining bennefit of the ISS as abstract biology and materials science is curtailed, the question will be ever louder... Why are we doing this again?
Why really? To try and make France/Germany/Russia like us? All the money in the world wouldn't change that.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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GCNRevenger we must make the better out of this situation of ISS and shuttle or there will be no more Nasa.
The bad part is shuttle has flown only the once in what will be 2 years and Nasa has not save any of the funds in its shuttle budget. This is bad for the last count on the ET's there were maybe 4 complete and 2 that were various stages of build. 2 of these tanks are returning hopefully for a successful fix this time. I do not a reference for how many SRB's are in stock but the ones for Atlantis of this year had to be pulled off because they were reachng there shelf life.
The way I see it do not modify the tanks to fix the foam but use them for the first sdv HLLV and use the next available srb's even if they are close to there shelf life. This gives the first round test flights if done soon for nearly nothing.
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Why really? To try and make France/Germany/Russia like us? All the money in the world wouldn't change that.
I'll give you a little bit of advice. If you want Canada to like you then end the tariffs on softwood lumber and pay back the money collected so far, as the US is required to do according to the NAFTA commission decision. Do nothing about wheat; tell Senator Byron Dorgan of North Dakota where to shove it regarding further wheat complaints. We came to an agreement regarding water diversion for Devil's Lake.
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GCNRevenger we must make the better out of this situation of ISS and shuttle or there will be no more Nasa.
The bad part is shuttle has flown only the once in what will be 2 years and Nasa has not save any of the funds in its shuttle budget. This is bad for the last count on the ET's there were maybe 4 complete and 2 that were various stages of build. 2 of these tanks are returning hopefully for a successful fix this time. I do not a reference for how many SRB's are in stock but the ones for Atlantis of this year had to be pulled off because they were reachng there shelf life.
The way I see it do not modify the tanks to fix the foam but use them for the first sdv HLLV and use the next available srb's even if they are close to there shelf life. This gives the first round test flights if done soon for nearly nothing.
Maybe your right space nut. What good is the shuttle if it doesn’t fly. If we have everything ready for a flight and we are not using it before it’s shelf life runs out because of unmanageable safety practices perhaps it is just time to suck it up and cross your fingers. If the shuttle blows up at least we don’t have to worry about flying it anymore. In the days of Apollo people believed they had a one in four chance of dieing with each flight. Well, the shuttle is much safer then that. However, it is still unsafe but we are stuck with it. So let us use what we have and be done with it then start the VSE.
Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]
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Most modules for ISS are complete and sitting in a staging building at KSC. I listed several options to launch them and complete ISS. Using just the Shuttle for 23 launches (from the consolidated launch manifest) plus Hubble, Node 3, and the US Habitat for a total of 26, is the worst one possible. There are several other options:
• Russian space shuttle Ptichka
• EELV (Delta IV Heavy or Atlas V 55x) plus stabilization thrusters, a US-built on-orbit tug would rendezvous and pull it back to ISS
• EELV + thrusters & Progress
• SDV & tug launched with cargo, no rendezvous necessary
• SDV & Progress service module
• SDV & Shuttle orbiter
• Energia & Progress service module
Each EELV could only lift 1 shuttle load of parts, and most missions would require structure to lash loose parts together. Total lift mass of either EELV is lower than the Shuttle cargo bay even before accounting for structure and stabilization thrusters, so may require re-configuring loads. A US built tug wouldn't need a docking collar; it could use an end effector like the hand at the end of CanadArm. No need for an arm, though, just manoeuvre the tug to position the end effector over a grapple post. The on-orbit tug could be refuelled. As an estimate, the original Progress service module has 500kg of propellant so assume the tug uses the same. The fuel module of Progress-M carries 1,200kg of propellant plus 1,340kg of cargo. One Progress-M could provide 2 tug missions with a little left over for the station. Doesn't sound worthwhile, but it also carries cargo. Progress-M1 carries 2,230kg of payload of which up to 1,950kg can be fuel, the rest cargo. Now we're talking. That's enough fuel for 4 missions of the on-orbit tug plus 280kg of cargo.
If you want a more detailed calculation, the Shuttle orbiter carries 1,000 pounds of propellant for OMS. RCS has a total of 1,464 pounds of oxidizer plus 923 pounds of fuel. That's a total of 3387 pounds (1539.5kg) of propellant for on-orbit operations, but it has to push around both the orbiter and its cargo. The orbiter masses 104.3 tonnes on landing, I don't know its mass while on-orbit (OMS & RCS tanks still mostly full). It can carry 16.05 tonnes of cargo to ISS so let's say the total is 120.35 tonnes. A tug will have to push 16 tonnes of cargo plus 3 tonnes of tug for a total of 19 tonnes. That means 19/120.35 = 15.8% as much. Propellant required should be 15.8% * 1539.5kg = 243kg of propellant. The 500kg estimate from an original Progress service module is actually about double. It depends how close to the station the launch vehicle can deliver payload; the closer you get the less fuel the tug needs.
However, the EELV with reusable tug and Progress fuel tanker is the complicated option. It would be simpler to launch an expendable tug with several modules on an HLLV such as a SDV or Energia.
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25 Shuttle flights isn't going to happen without extending the 2010 deadline, and even the reduced manifest 15-flight plan is rapidly becoming impractical every day that the next flight is delayed.
None of the EELVs have the lifting power to bring up the heaviest modules and payload cradles and tugs for them, without which they won't stay stable for sure. So, the EELVs will have to be modified to make them more powerful to serve this role.
HLLV is not available, and won't be for several years probobly even if Shuttle went away starting tomorrow. If there are any delays, it will cut into the six or seven years of "complete" life the ISS will have. It too will need tugs and payload cradles.
Frankly, I question if Progress is advanced enough for the very careful maneuvering required to put payload modules within reach of the arm with sufficent precision reliably.
No viable option is going to possibly cost less then $5-10Bn, which when you add the ~$2Bn/yr engineering cost and another ~$2.0Bn for CEV crew, cargo, and parts from 2012-2017, any way you slice it the ISS is going to soak up a minimum of ~$35-40Bn, which is about half of NASA's budget. In return, NASA won't get much of anything except to not "offend" our partners by falling on our sword.
Pressing Shuttle back into service when we know there is a serious, reoccuring, and fatal problem is unacceptable. Astronauts might not have any trouble going lemming on us, but NASA wouldn't survive the political fallout of killing another crew the same way as Columbia, which almost happend to Atlantis and Discovery too.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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I know EELVs don't have enough lift capacity to carry modules with a tug, that's why I said launch the tug separately and just put on the module a tiny stabilization thruster that prevents it from spinning. The tug can come from the ISS to grab the module and pull it to ISS. However, this is the complicated option.
During the cold war it was part of American culture to characterize Russians as lazy, slothful, and uneducated. They claimed Russian fighter planes were inferior. However, they found planes performed as well or better than American planes. America had to stay on its toes to keep up with Russian fighter plane technology. America was ahead with electronics, slightly ahead with torpedoes for submarines, but slightly behind for fighter manoeuvrability. Today the Su-27 Flanker can out manoeuvre an F-15 Eagle or even an F-22 Raptor. Russia's stealth technology is nowhere near America's, only stealth makes the F-22 superior to the Su-27. Don't make the same mistake with Russian spacecraft.
When I said you could use a Progress instead of an American built tug, I did not say move the module close enough for CanadArm2 to grab it. I said dock. That means use the Progress with it's docking collar to connect directly to the docking port of one of the existing modules on ISS. That's how it operates now, the only difference is increased mass. Since the fuel to mass ratio of Progress is roughly twice as great as the Shuttle orbiter, I said 2 Progress service modules could move a group of 5 ISS modules lashed together. Once the forward Progress is hard docked to ISS, then the arm can pluck off modules one at a time to move them into place.
As for Shuttle: I gave my solution several times. The problem is bursting cells of the closed cell foam as it ascends rapidly into the stratosphere. This creates voids that did not exist at launch; those voids are weak spots that let foam break off from aerodynamic pressure when flying at hypersonic speed. Once a piece of foam breaks off, much of the foam behind will peal off like an orange skin. There's also the problem that foam in the close-out areas sprayed on by hand is only rated for cold as low as -70°C; it becomes brittle below that. Foam over the acreage can handle deeper cold, but published spec's say it can only handle -183°C; that's the exact temperature of liquid oxygen. The foam on the LOX tank is to a degree the absolute minimum rated service temperature, no margin. Don't you think the foam will be brittle? Liquid hydrogen is -253°C so foam over the LH2 tank is 70° below its rated minimum temperature. However, aerodynamic pressure is greatest at the slope of the LOX tank.
My solution is a spray applied polymer film to catch any foam that comes off. Don't try to eliminate foam detachment, rather keep it contained within a giant condom. Polyimide is very strong yet able to handle cold. Fluoropolymer film can handle temperatures colder than liquid oxygen, but I've never read about a spray-on fluoropolymer. Teflon FEP and PCTFE can handle -240°C, PTFE can handle -212°C, and ETFE (Tefzel) can handle -185°C, but again the problem is applying it. Polyimide can handle cold and spray applied. Solimide can handle -184°C but its foam, not film. Kapton type HN can handle cold to -269°C. The outside of the insulation foam will not be as cold as the metal of the tank, after all its purpose is thermal insulation, but Kapton can handle it anyway.
Kapton type 100 HN film, 1 mil thick at 23°C
ultimate tensile strength: 231 MPa (33,500 psi)
yield tensile strength: 69 MPa (10,000 psi)
tear strength-propagating (Elmendorf): 0.07 N (0.02 lbf)
tear strength-initial (Graves): 7.2 N (1.6 lbf)
Density: 1.42 g/ml
Based on 1 mil film and a rough estimate of the area of the ET, film mass should be 46.69kg. The question then becomes how to apply the film. Spray on is preferred, but these specifications are for factory made film. DuPont says "Kapton® is synthesized by polymerizing an aromatic dianhydride and an aromatic diamine." Can that be polymerized in place the way polyurethane foam is applied? Or would it have to be wrapped?
For the PAL ramp, I said replace it with open cell foam sealed in polymer film and filled with helium gas. Helium will not liquefy at liquid hydrogen temperature. You could use Teflon FEP, PCTFE, but now that I see the specifications for Kapton type HN, that would be better. Adhere the PAL ramp directly to metal, so crumbling closed cell foam will not let the PAL ramp come off. Make a small thin spot in the PAL ramp film that can blow out from pressure and a reinforcement ring around that spot so the tear cannot propagate. Basically each piece of PAL ramp forms a single closed cell; the thin spot lets it burst in a controlled way.
Is that detailed enough? Can we just get on with it and get the Shuttle flying again?
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Thanks to Bwhite here is a reference for the ISS and its possible uses.
Many bullets that I have in the quote area we have talked about as for reasons that the ISS is of use for the vision.
Question on the use of the EELV's, why would we GCNRevenger want to use it to lift the heaviest of modules when it could lift the lesser items and by doing so cut the number of flights that a shuttle is needed to be used on.
With RobertDyck attached thruster method could the shuttle be used to bring multiple previously launched by the EELV's to the station with its cargo bay doors open and a latching arm or bracing extentions to the modules once catching up to them in orbit.
[url=http://www.spaceref.com/news/viewsr.html?pid=18740]NASA and the Business of Space American Astronautical Society 52nd Annual Conference
Michael D. Griffin NASA Administrator 15 November 2005[/url]
So, how can the ISS that we are building today help us to move beyond low Earth orbit tomorrow?
To begin, we are focusing human research on ISS on the highest risks to crew health and other issues we will face on long exploratory missions.
With the ISS as a testbed, we can learn to develop the medical technologies, including small and reliable medical sensors and new telemedicine techniques, needed for missions far from home.
The ISS can host, and test, developmental versions of the new lox/methane engines we will need for the Crew Exploration Vehicle (CEV), and many other systems that we will need for Mars. These include the development and verification of environmental control, life support, and monitoring technologies, air revitalization, thermal control and multiphase flow technologies, and research into flammability and fire safety.
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There is no such thing a small, easy, cheap, light weight "small thruster method" for stabilizing heavy modules: you've got to have solar cells and eclipse batteries for them for power, sizeable thrusters and fuel reserves since the payload is so heavy, attitude systems (eg gyros) so you know which way you're pointed, antennas and hookups for remote control... basically, a tug, just without guidence hardware. It would be easier to just go ahead and build a tug, bolt it on the payload cradle, and use a more powerful launch vehicle.
You can't wrap the tank in Kapton, especially not the uber-thin 1mil variety. We have 2mil Kapton at the office, and while the stuff has pretty good tensile properties, it tears very easily. The slightest rip or cut in the stuff, in a hypersonic air flow, and it would peel right off the tank. I doubt a thin layer of it would be strong enough to resist any explosive bursting or overpressure either.
The imidation process to make the stuff isn't suitable for spray application either, plus it isn't readily compatible with adhesives (its nice since things won't stick to it). If just wrapping Kapton around the tank do the job, NASA would have done it already.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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If you use an EELV rather than a big SDV, the thrusters would only prevent spinning/tumbling, not any sort of manoeuvre. That means the thrusters can be much smaller with small fuel tanks. Gyros are used to control spinning and/or orientation because they use electricity instead of propellant. That's great for long term application, but for just a couple days you're better off with thrusters alone, no gyro. The only electrical power will be for control electronics, and that will be only a couple days so a primary battery will do the job. A lithium battery (not lithium-ion) can provide power with a density of 500Wh/kg. That's a lot better than 150Wh/kg for lithium-ion, but a primary battery cannot be recharged. Again, fine for a couple days.
New solid state rate gyros use a vibrating quartz crystal. Very tiny. They're not good enough to maintain orientation, but enough to prevent tumbling. It doesn't matter which direction the grapple post is pointing, just that it isn't moving.
You don't need hook-ups. Let the module be dead weight, use the tug to haul it to ISS and dock at a docking port. However, CanadArm2 for the station uses the grapple post itself to provide both power and communication. The end effector has 3 cables inside, they draw tight against the post and pull. They catch the knob at the end of the post and pull the cylinder of the end effector down against the disk at the base of the post. The cables for one electrical contact with the post, the end of the cylinder forms the other electrical contact with the disk. AC power provides power to the arm, and that's used as a carrier wave to modulate a data signal. CanadArm2 has an end effector at each end of the arm, it can move across the station by grabbing with one end before letting go with the other; it "walks" from grapple post to grapple post. Works for the station; can also provide hook-up from tug to module.
I knew GCNRevenger could give me insight into Kapton. DuPont claims the film can be treated to provide a surface for adhesive. I don't know what the treatment is, but they say it's available. Teflon FEP can also be treated on one or both sides to accept adhesive. Since its Teflon it has to be treated to accept adhesive, but it's a stock option. Should be straight-forward to fabricate the PAL ramp.
And don't assume NASA has thought of everything already. They're only human, they can't think of everything. They need people like us coming up with new ideas.
So we need something form-fitting over the tank without seams that can be caught in hypersonic wind. That sounds like a spray application. What is the imidation process? If we have an environmentally controlled chamber to apply the film (at Michoud) what would it take? As for tears, it sounds like we need a fibre for rip-stop. Glass fibres should do the trick. Could we mix a small quantity of glass fibres into the liquid so it's included within the film when it sets?
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With the ISS as a testbed, we can learn to develop the medical technologies, including small and reliable medical sensors and new telemedicine techniques, needed for missions far from home.
I don't see why they need ISS for that? You can develop, and test that stuff on the ground, no?
While having ISS around to do some final testing of said equipment/techniques might be convenient, it surely is not a reason for its existence.
IMO, the only defendable uses have got to have 'long-term micro-gravity effects' in their descriptions, all the other stuff can be easily done on Earth. I really think they're making a mistake in cancelling virtually all tech experiments onboard, even if ISS isn't the ideal setting for that.
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These are not satelites that only weigh a few tonnes, we're talking payloads in the 20MT region, which will require substantial thruster or heavy gyro capability to prevent natural spinning. Itty-bitty gyros would be completly useless for effecting any sort of attitude control of a mass this size.
Making the assumption that whatever ISS payload carrier will only be needed "a few days" is pretty - okay, maybe extremely - risky given the possibility of delays from Shuttle or a tug picking up the module to tow it to the ISS. It does indeed matter which way the grapple is pointing too, since the module would virtually have to come into contact with the station if the arm had to reach around to the "back" of the module.
Imidation is a real pain, where you take the somewhat unstable poly amic acid, which is fairly reactive and tends to degrade if not handled carefully, and then heating it up under inert atmosphere or vacuum to complete ring closure to form poly imides like Kapton. Its not real practical to do on an object the size of the Shuttle ET.
I don't think NASA has the time to come up with a brand new material for a sheeth, it is going to have to be something off the shelf. Certainly no coming up with a brand new composite that has its own set of question marks. A metal mesh, something like a high-strength version of "chicken wire," would be what I would look into first.
Don't bother with the PAL ramps, they were added to since NASA was parinoid and they aren't really needed. Rip them off and go back to the way the tanks used to be built, and problem solved.
One problem with open-cell foam is that air would be able to access the metal surface of the tank and liquify, which would add immense weight if even a small fraction of the foam become saturated with it, and might blow out anyway since the pressure drops so suddenly on launch. Then there is the unknown behavior if the air inside an imperable-coated foam liquifies or contracts and creates a vacuum. Thats something of a risk and a big question mark that should also be avoided.
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And this...
Hey Mike, really, somebody's head needs to roll here. The tank gets cracks in it sitting in a hanger and you expect it not to under the stress of launch?
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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The tiny rate gyros I mentioned are sensors only, they don't move anything. The sensors provide data to an electronic controller that fires thrusters. Stabilization to prevent spin is accomplished by thrusters alone. You can do this with any spacecraft, the catch is thrusters require propellant.
As for the film, you do have a point that NASA has to do this quickly. When I first looked for a spray-applied polymer film I came across the news announcement that Audi is using it to protect the paint on Cars. They used to use wax but it cost money and time for a dealership to send a car out to get it removed. I found an article on Audi's web site, it says Canada and the US now have environmental regulations that strongly discourage the polution caused by solvents and wax with all that water washed down the drain. The problem isn't applying wax, it's removing it. But this makes me think we need to look at the polymer film that first got me on the idea. Since the foam is spray-applied I thought a film could be too, the film used by Audi is the only one I found.
The Audi web page says they use "an aqueous polyester-polyurethane dispersion". Would that survive the conditions of launch? Foam is supposed to be a thermal barrier, what would the outside temperature be? How thick would the spray-applied film be?
Since the Audi article mentions a patent, I searched for a patent. I didn't find one by Audi but did find spray-applied films for patents 20050250901 and 20050249958. The patents are rather long and I don't see a material data-sheet, so don't know how to evaluate them.
Couldn't we just use Audi's film?
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Interesting quotes attributed to Mike Griffin.
One example:
"I firmly believe that if a few officers and enlisted men can launch a Trident D-5 [tactical missile] out of a submarine that stands off-shore from the Cape here, that we ought to be able to find a way to have a comparable number of people to launch our space vehicles ... and that will only happen if we design it in on the front end ... and that will only happen if we (appropriately) use a high tech approach is what we need to accomplish that."
November 16, 2005
= = =
If the foam is indeed cracking in the hanger perhaps orbiter will not fly again. I certainly won't whine.
Give someone a sufficient [b][i]why[/i][/b] and they can endure just about any [b][i]how[/i][/b]
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As for the film, you do have a point that NASA has to do this quickly. When I first looked for a spray-applied polymer film I came across the news announcement that Audi is using it to protect the paint on Cars. They used to use wax but it cost money and time for a dealership to send a car out to get it removed. I found an article on Audi's web site, it says Canada and the US now have environmental regulations that strongly discourage the polution caused by solvents and wax with all that water washed down the drain. The problem isn't applying wax, it's removing it. But this makes me think we need to look at the polymer film that first got me on the idea. Since the foam is spray-applied I thought a film could be too, the film used by Audi is the only one I found.
The Audi web page says they use "an aqueous polyester-polyurethane dispersion". Would that survive the conditions of launch? Foam is supposed to be a thermal barrier, what would the outside temperature be? How thick would the spray-applied film be?
Since the Audi article mentions a patent, I searched for a patent. I didn't find one by Audi but did find spray-applied films for patents 20050250901 and 20050249958. The patents are rather long and I don't see a material data-sheet, so don't know how to evaluate them.
Couldn't we just use Audi's film?
You are talking about needing a material that has excelent tearing properties, really strong and able to hold in foam even if a major overpressure blows it out hard. None of this "film" business, no kind of thin layer is going to have sufficent properties no matter what its made of. It will also need at least some thermal resistance, since its going to get awfully cold in the upper atmosphere or hot from friction.
The film applied to the cars is designed for just one thing: ease of application. I doubt that it has the high strength properties across a whole range of temperatures. I bet that it would have to be relativly very thick to offer the mechanical performance needed.
Plus, you have the problem of what happens if gasses build up under it or a vacuum void forms, in which case bad stuff might happen. NASA can't afford question marks like that any more then it can to come up with a brand new material.
Its got to be porus, its got to have maximum rip properties for minimum mass, and it has to handle temperature variences. A high-strength counterpart to "chicken wire" or a mesh made of high-strength polymer fiber (pressed flush into the foam if needed) over the orbiters' 40% of the tank is the way to go.
Simple, relativly quick, and a minimum of question marks.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Interesting quotes attributed to Mike Griffin.
One example:
"I firmly believe that if a few officers and enlisted men can launch a Trident D-5 [tactical missile] out of a submarine that stands off-shore from the Cape here, that we ought to be able to find a way to have a comparable number of people to launch our space vehicles ... and that will only happen if we design it in on the front end ... and that will only happen if we (appropriately) use a high tech approach is what we need to accomplish that."
November 16, 2005
= = =
If the foam is indeed cracking in the hanger perhaps orbiter will not fly again. I certainly won't whine.
Apparently it was due to filling and re-filling the tank with cryogen fuel several times, back when the tank had the malfunctioning fuel level sensor.
Interesting that Griffin said these things, even provocative given the political inertia to keep the Shuttle Army no matter the cost.
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Edit: If Griffin actually said these things in the link... this is definatly a big deal. Griffin must have seen the handwriting on the wall about VSE costs ballooning out of control with a "business as usual" approach with the same people as Shuttle running the operation, and is pretty much frantic.
This is the strongest kind of phraseology that I have ever heard out of him, and taken to its logical conclusion, is at least to large degree in contradiction to Congressional wishes, at least in spirit, and against the NASA "one big happy family" phenomenon.
I think given the debacle over Shuttle's external tank, that Griffin should consider approaching Boeing - which already has a highly automated rocket factory for Delta-IV - and cut Michoud and Stennis loose.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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Interesting quotes attributed to Mike Griffin.
One example:
"I firmly believe that if a few officers and enlisted men can launch a Trident D-5 [tactical missile] out of a submarine that stands off-shore from the Cape here, that we ought to be able to find a way to have a comparable number of people to launch our space vehicles ... and that will only happen if we design it in on the front end ... and that will only happen if we (appropriately) use a high tech approach is what we need to accomplish that."
November 16, 2005
= = =
If the foam is indeed cracking in the hanger perhaps orbiter will not fly again. I certainly won't whine.
Wow! Bill. Those are amazing quotes for Dr Griffin from that link.
Dig into the [url=http://child-civilization.blogspot.com/2006/12/political-grab-bag.html]political grab bag[/url] at [url=http://child-civilization.blogspot.com/]Child Civilization[/url]
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These Griffin quotes are big enough news that I think the text ought to be copied here directly and not as a link that might disappear or be unread:
""If we design another space launch system that requires $4.5B per year to do no launches at all ... just to own the system, then we will be put out of business ... we will be put out of business!"
"I'm counting on, and I am pleading with, the engineers on the design side and with the engineers on the operations side to work together!""
...and...
""We need a system that needs a smaller support base to keep it alive, if we expect to keep alive. The only way to do that is to use fewer people on any given thing. Now, we're still going to have the same overall budget - we want to use that budget to buy other functions. Again, I want you to do more things - other things than have everybody crowd around one space launch vehicle ... and that's what we're going to have to use high tech for.""
Just let that sink in for a minute...
"we will be put out of business"
"if we expect to keep alive"
I am starting to wonder if we should expect Griffin to resign by the end of 2006 at this rate, if it became obvious that VSE would fail.
[i]"The power of accurate observation is often called cynicism by those that do not have it." - George Bernard Shaw[/i]
[i]The glass is at 50% of capacity[/i]
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