More ISS hardball - How does this affect US vision?

GCNRevenger · 2004-12-16 17:58:21

There is no need for transport to or from the ISS, since it is worthless and wouldn't last but a few years past the time when a space taxi could be built. A Lunar mission will likly employ direct return which would dictate a capsule, particularly with limited LSS capacity being fatal with taxi launch delay.

"N2O4 requires something non-reactive with an oxidizer, but there are several polymers even more imperable to oxygen than Kel-F..."

Huh? Nitrogen Tetraoxide is a horribly reactive substance, and it may very well cause composit fuel bottles to disolve.

I'm thinking of a TSTO vehicle capable of carrying heavier payloads, a true "Shuttle II" as it were. For the day that we need launch capacities beyond even what HLLV can provide.

RobertDyck · 2004-12-16 19:17:13

"N2O4 requires something non-reactive with an oxidizer, but there are several polymers even more imperable to oxygen than Kel-F..."
Huh? Nitrogen Tetraoxide is a horribly reactive substance, and it may very well cause composit fuel bottles to disolve.

Fluoropolymers are notoriously non-reactive. Even N2O4 won't touch it. I don't know about nylon or other cheap polymers, though. It's probably best not to go cheap with something as toxic as nitrogen tetraoxide.

GCNRevenger · 2004-12-16 19:20:01

Yes I know fluropolymers are pretty inert to common things, but some less so then others. Nitrogen Tetraoxide is definatly not a normal thing either.

RobertDyck · 2004-12-16 19:45:45

DuPont FEP film is chemically inert and solvent-resistant to virtually all chemicals, except molten alkali metals, gaseous fluorine, and certain complex halogenated compounds such as chlorine

I expect other fluoropolymers, such as Kel-F, to be the same. According to http://www.tecan.com/index/com-pr-ap_so … .htm]Tecan Kel-F is "resistant" (non-reactive) to everything except chloroform and perchloric acid, and it's "partially resistant" to even those. An oxidative compound like N2O4 won't affect Kel-F.

GCNRevenger · 2004-12-16 19:51:43

Perchloric acid is very much an oxidizer if it gets warm, above about 150C it gets down right nasty. I don't think it would resist extended exposure to N2O4. Solid rocket engines even use Perchlorates as oxidizer.

RobertDyck · 2004-12-16 20:03:44

Perchloric acid is very much an oxidizer if it gets warm, above about 150C it gets down right nasty. I don't think it would resist extended exposure to N2O4. Solid rocket engines even use Perchlorates as oxidizer.

"halogenated compounds" means chemicals that contain a halogen. Halogens are one column of the periodic table, characterized by electrons in 5 of the 6 P orbital positions of the valence shell. There are 3 orbitals each holding one electron of each spin, clock-wise or counter-clockwise. Elements tend to 8 electrons in the valence (outer most) shell; 2 in the S orbital and 2 in each of the P orbitals. The halogens attract an electron most strongly since that completes the set of 8. That makes halogens extremely reactive with any element that has few electrons in the valence shell. The halogens are fluorine, chlorine, bromine, iodine, and astatine. The yet unnamed element with atomic number 117 would also be a halogen, but it has a half-life of a fraction of a second so it doesn't matter.

Chloroform and perchloric acid contain chlorine, a halogen. Nitrogen tetraoxide doesn't contain fluorine, chlorine, bromine, iodine, or astatine so it isn't reactive. If you want to test that assertion, go ahead. I don't have any N2O4 handy.

Ok, so you can't use fluoropolymers to contain perchlorates. You don't need a composite tank to contain solid rocket fuel.

GCNRevenger · 2004-12-16 20:24:37

I happen to know a little bit about chemistry. After all, it is my profession.

Your argument that potent oxidizers won't react with fluorine-bearing organics due to their high electron affinity doesn't tell the whole story nor is it accurate about all oxidizers. You also skiped the part about there being numerous C-C bonds in Kel-F as well as C-F bonds, and how groups of atoms can form more potent oxidizers then individual ones.

Suffice it to say that N2O4 is a middle-upper strength oxidizer probobly only a little less potent then perchlorates, and could likewise degrade Kel-F.

RobertDyck · 2004-12-16 20:53:10

Ok, so it needs to be tested. I happen to have samples of Teflon FEP and Tefzel films. I'm accumulating samples for material exposure racks to be deployed at MDRS and FMARS. DuPont still hasn't provided the thin films of Teflon FEP. (grumble, grumble, salesman get off his ass, grumble, grumble) I'm now going to try to get Kel-F to add the set before deploying the test. But I don't have dangerous chemicals like nitrogen tetraoxide sitting around my house. My job is developing the hardware and software for an automated calibration system for sensors of an autopilot for miniature UAVs. We have a small shop, but no N2O4. Why don't you test it and see what it does? I'ld love to hear the results.

Austin Stanley · 2004-12-16 23:27:38

The solution for composit tanks would be a thin coating of a more corrosion resistant material, in this case probably titanium or zincronium. Although I'm not sure how exactly you would deposit such a coating onto the inside of a composit tank. Conventional plating techniques obviously will not work on non-metals.

That said most chloroflourocarbons (like Teflon and Kel-F) are okay for working with Perchloric Acid that is fairly concentrated. Heck, even some common plastics like polyethylene and polypropylene could be used. But that doesn't necessary apply to anhydrous (>85% concentration) perchloric acid, and like GCN when the stuff is heated it is dangerously reactive/explosive even. I'm not sure if Kel-F could stand up to it, you would have to test it.

GCNRevenger · 2004-12-17 11:05:51

I'm thinking that if perchlorate will attack polymer because it is a strong oxider when heated, then so would N2O4.

Test it? I don't relish the idea of handling the stuff, and I would have to talk the boss into buying some... we don't leave that kind of thing sitting on the shelf.

SpaceNut · 2004-12-17 11:51:48

N2O4 MSDS fact sheet

other data

This one has chemical boiling point

Yup I would say pretty nasty stuff from the quick look.

SpaceNut · 2005-01-06 13:55:48

Russia To Focus Its ISS Projects

Well the Russians are not sitting by idle with there plans to use the Station to its fullest in the air.

Russian ISS segment would be complete by 2011. Plans call for launching into orbit a multi-purpose laboratory module in 2007, a science and power platform in 2009, and another laboratory module in 2011.

What segments does the US have remaining to place into orbit?

SpaceNut · 2005-01-13 06:50:33

Well from this news release it appears that the Russian's are not letting up with launches to the ISS. The plan is to launch two manned Soyuz spaceships and four Progress cargo spaceships to the ISS this year. How many will the US be doing if the shuttle does not fly...

Russia to launch six spaceships to ISS in 2005

SpaceNut · 2005-01-20 08:07:47

Well the Russian and the ESA have been hard at work hammering out the agreement for the Russian Rockets to Fly From Equator from the new launch pad and other infrastructure on French Guyana's Kourou Island.

SpaceNut · 2005-01-24 12:23:53

Just like clock work the ISS is being resupplied by the very partner that does not want free loaders and why should there be.

The next Progress” cargo vehicle to be launched to ISS on February 28

They also noted that it was planned to send to the ISS two piloted “Soyuz-TMA” spaceships and four cargo vehicles this year (one every quarter of the year). “All the launchings will be carried out within the framework of the International Space Program from five launching pads of the Baikonur cosmodrome by means of Soyuz-type boosters.
The International Space Station now has four modules with a total inner space of 470 cubic metres. Its mass tops 180 tons. It is planned to complete the building of the station by 2010. By that time, the “orbital structure” is to grow up to twenty-six modules and elements (six of them will be Russian) and the station’s mass will then equal to about 400 tons.

SpaceNut · 2005-01-31 06:28:28

Well the planning stages are set for when the shuttle retires though no one knows quite what that will mean as of yet.

What do we do with the ISS?

At the heads of agency meeting last week in Montreal few indications were given about the long-term future of the International Space Station.

In fact NASA’s international partners are scratching their heads trying to figure out what the US is really planning to do with the ISS after the last shuttle mission has undocked from the ISS with the last load of large items to be returned safely to Earth?

The big question for the next NASA administrator will be whether he going to reverse the decision to delete the ISS service role from the Crew Exploration Vehicle’s mission.

the feeling in Washington seems to be, “let’s just commit ourselves to finish building the thing and we’ll figure out what to do with it later.”
While this may be typical of the way things happen inside the US Government it leaves the Europeans and the other partners thoroughly puzzled. Is there really no plan for the $100-billion “world-class” orbiting laboratory other than the few long-term exploration oriented developments that are currently in the works? It seems that NASA has not been able to develop a plan that can realistically fit post-2010 or 2014 ISS operations into its current budget plan.

The mission, the business, and the tandem

The concept of government-led exploration of the solar system requires a determined commitment by space agencies that could be “very much a hostage to fortune”.

With that said the US appears also to be held hostage to the present.

GCNRevenger · 2005-01-31 07:55:37

Not having any plans to use the ISS is a good thing, because the ISS is useless, wholey and utterly. There is not enough science that can be performed there to justify its cost, the ISS has always been a make-work program for US and Russian space agencies.

If other governments want to piddle around with it, fine, but we're going to the Moon.

Commodore · 2005-01-31 19:14:48

Not having any plans to use the ISS is a good thing, because the ISS is useless, wholey and utterly. There is not enough science that can be performed there to justify its cost, the ISS has always been a make-work program for US and Russian space agencies.
If other governments want to piddle around with it, fine, but we're going to the Moon.

Its all apart of our master plan to handicap the rest of the world with a 1980's designed rickety old station while we do bigger and better things.

That said, I still think that theres a need for an orbital platform. One capable of varitable gravity, growing food (and actually eating it) of both the crop and livestock varieties, testing space reactors and active radiation defenses.

Basically simulating a full Mars transit.

GCNRevenger · 2005-02-01 06:55:33

That said, I still think that theres a need for an orbital platform. One capable of varitable gravity, growing food (and actually eating it) of both the crop and livestock varieties, testing space reactors and active radiation defenses.

We don't need an orbital platform for these things. And at this moment, we will be hard pressed just to have the money to get to Mars at all without throwing a few billion at a space station we don't need.

-Growing of plants or fish, which is all basic Mars missions will have capacity for, has been studied enough to understand how to manage in zero-G. We've been doing plants for decades.

-Simulating variable gravity is not important, the transit to Mars is short enough artifical gravity is likly not needed... if it is, then Zubrin's method would be easy enough and wouldn't need in-space testing.

-Space reactors with reasonably low liquid or any gas coolant flow rates are not botherd much by gravity, and can be tested right here. In fact, they can be tested much better, since you cannot safely recover a space reactor for study for wear&tear/failure modes.

-Radiation defenses or other studies in radiation tollerances can be tested here too, a small particle accelerator shooting protons, alpha particles, and iron nucleii would be more then capable of simulating the space radiation environment right here on the ground.

In any event, the ISS can do none of these things. It cannot have an artifical gravity capability that people could operate in, it is below the Earth's Van Allen belts so that it cannot be used for radiation testing, it is too small to grow animals, and there is no way through any practical means to bring a hot nuclear reactor back to Earth safely.

SpaceNut · 2005-02-01 09:09:09

Well if you were on board here is something that you would hope not occur during a [url=http://msnbc.msn.com/id/6890895/] Spacewalk. Station thruster fires set off incident alarms within NASA.
Coordination breakdown could have led to toxic exposure.[/url]

During the spacewalk, the station's stabilizing gyroscopes repeatedly became overloaded with a mysterious torque, and they had to be relieved periodically by firing rocket thrusters located on the Russian half of the station. On at least one occasion, and contrary to agreed upon mission rules, these thrusters appear to have been activated when the two crew members were working dangerously close to them.
This put them at risk of both thermal damage from the thrusters themselves and, more likely, to chemical contamination from the fuel used by the thrusters. Even in small amounts, any fuel splashed on the space suits could render the air toxic in the station when the men returned from their spacewalk.

GCNRevenger · 2005-02-01 11:41:42

Wow, it just keeps on getting worse. The Incredibly Stupid Station is just plain comic... or at least until someone gets killed. Which they already have if you consider Columbia.

clark · 2005-02-01 11:55:11

Columbia exploded on a scientific mission- it didn't go to the ISS on its last mission.

just a minor quibble.

SpaceNut · 2005-02-01 14:07:49

HTV spacecraft eyed as supply vehicle
This is sort of IMO hush hush so as to not anger the russian but if we can pay for these rockets though the nation of Japan. why not Russia? The safe guard of financing the russian military IMO is a moot point if they are truely our partners in space.

Grypd · 2005-02-01 14:33:16

This is ridiculous.
The ISS is having to use its thrusters as the basic system to keep it spinning the right way has Overloaded

The ISS is still suffering from the occasional recurrent unexplained noises though the Mission controllers now think its the result of stress being put on the whole frame. There where those nasty dent pictures.

The ISS keeps having its air supplies get low as the main system to manufacture and purify the air keeps breaking down.

The ISS has real difficulties for feading the much reduced crew aboard as its supplies are reliant on the Russians who never planned to have to do the whole deal..But hopefully the ATVs will be up and running soon.

The ISS is hardly finished and is going to take ages if ever to be done as long as we get the shuttle working as no other option is available to send the modules into space and its very unlikely to be able to do any real science before it simply wears out from age

The ISS is in the wrong orbit for development of space and it really has no future potential in that regard. If we need to go to the Moon we will need to create Another station to be able to develop those potentials.

The ISS is causing real problems in international relations with the Russians actually calling the shots but with everyone blameing NASA for why they cannot get the Billions they have spent to create modules to go up there. Especially as NASA in the past had blocked alternative launchers sending up there own modules or creating modules with seperate power supplies.

The ISS has become what it was not to be a floating failing white elephant. A lot of good work went into the creation and design of the various modules to be utterly wasted. I find it very frustrating.

GCNRevenger · 2005-02-01 15:35:58

I know that Columbia wasn't going to the ISS... what I was getting at was that the ISS is in large part - no, let me rephrase - the justification to continue flying Shuttle. Without the ISS, the Columbia science mission would not have been justifiable against the cost of Shuttle operations, and would not have been flown. Shuttle would have been essentially retired years earlier.

And no, we do not need a new space station to get to the Moon. The development, construction, and launch of a space station as a Lunar way-station, would bankrupt the Lunar program.

What we should do is to either adopt the Earth-Orbit-Rendevous method and use an upgraded Delta-IV heavy to launch Lunar payloads/ships and the TLI rocket stage to get there seperatly. The alternative would be to stick with the Saturn-style one shot Lunar flight with a new light-duty heavy lift rocket, except that the manned ship and lander would be sent seperatly to rendevous in Lunar orbit.

It makes me wonder if the current US & NASA administration are praying for a serious ISS fault so that the station could be abandoned and still save face. Otherwise, the most painless way out of this mess is let Shuttle fly another 20 times, no more, finish the ISS and call it quits with the Incredibly Stupid Station.

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#101 2004-12-16 17:58:21

Re: More ISS hardball - How does this affect US vision?

#102 2004-12-16 19:17:13

Re: More ISS hardball - How does this affect US vision?

#103 2004-12-16 19:20:01

Re: More ISS hardball - How does this affect US vision?

#104 2004-12-16 19:45:45

Re: More ISS hardball - How does this affect US vision?

#105 2004-12-16 19:51:43

Re: More ISS hardball - How does this affect US vision?

#106 2004-12-16 20:03:44

Re: More ISS hardball - How does this affect US vision?

#107 2004-12-16 20:24:37

Re: More ISS hardball - How does this affect US vision?

#108 2004-12-16 20:53:10

Re: More ISS hardball - How does this affect US vision?

#109 2004-12-16 23:27:38

Re: More ISS hardball - How does this affect US vision?

#110 2004-12-17 11:05:51

Re: More ISS hardball - How does this affect US vision?

#111 2004-12-17 11:51:48

Re: More ISS hardball - How does this affect US vision?

#112 2005-01-06 13:55:48

Re: More ISS hardball - How does this affect US vision?

#113 2005-01-13 06:50:33

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#114 2005-01-20 08:07:47

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#115 2005-01-24 12:23:53

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#116 2005-01-31 06:28:28

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#117 2005-01-31 07:55:37

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#118 2005-01-31 19:14:48

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#119 2005-02-01 06:55:33

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#120 2005-02-01 09:09:09

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#121 2005-02-01 11:41:42

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#122 2005-02-01 11:55:11

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#123 2005-02-01 14:07:49

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#124 2005-02-01 14:33:16

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#125 2005-02-01 15:35:58

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