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#501 2020-03-21 14:16:57

SpaceNut
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From: New Hampshire
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Re: International Space Station (ISS / Alpha)

The crew we have onboard will be staying a bit longer as the Astronauts grounded in Russia's Star City over virus

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#502 2020-06-21 20:00:54

SpaceNut
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From: New Hampshire
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Re: International Space Station (ISS / Alpha)

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#503 2020-06-22 07:53:39

tahanson43206
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Registered: 2018-04-27
Posts: 3,822

Re: International Space Station (ISS / Alpha)

For SpaceNut re #502

Thank you for showing the link to the article on the (unexpected) presence of benzine in the air circulating in the ISS.

I'd appreciate any member of the NewMars community who discovers further information about the air-quality measuring equipment installed by the Russians, to update this topic.  It seems to me that ** any ** spacegoing vehicle or habitat needs to be fitted with comparable equipment.

In very general terms, it seems to me that NO carbon should be present in air delivered to a human habitat.  Ideally, (it seems to me) an air delivery system should provide ** only ** oxygen and at most two inert filler gases.   

Therefore, work being done around the planet to identify contaminants in air should yield solutions that will be helpful in space rated air delivery systems.

Since electromagnetic radiation is available as a sensing medium, I was curious to know what might have been done to explore the potential of using light as a way to measure carbon in air.  Google came up with an interesting list of citations.

I was happy to see an entire web site dedicated to technology used for measurement of gases in an atmosphere.

Here is the top level of citations:

pubs.acs.org › doi
Feb 27, 2012 - A novel optical method for the determination of CO2 concentration in ... the carbon dioxide equilibrium between solution and the air above, the ...

Optical Sensing Scheme for Carbon Dioxide Using a ...pubs.acs.org › doi
Mar 25, 2011 - The detection limits are around 0.23% for gCO2 and 1.53 hPa for dCO2. ... monitoring carbon dioxide in the atmosphere(7) and in seawater,(8) ...

A Gas Sensor Device for Oxygen and Carbon Dioxide Detectionwww.mdpi.com › pdf
PDF
Aug 11, 2017 - [1] and more in general in the air quality determination [2]. ... Chu, C.-S.; Syu, J.J. Optical sensor for dual sensing of oxygen and carbon dioxide ...
by M Santonico - 2017 - Cited by 5 - Related articles

Optical determination of carbon dioxide and oxygen by a ...www.researchgate.net › publication › 333519825_Optical...
Request PDF | Optical determination of carbon dioxide and oxygen by a ... The sensor film is attached to the inner wall of an air-tight container integrated with ...

Two-wavelength thermal–optical determination of light ... - AMTwww.atmos-meas-tech.net › ...
Jun 13, 2019 - Thermal–optical analysis is widely adopted for the quantitative determination of total (TC), organic (OC), and elemental (EC) carbon in ...

SpaceNut .... your post here leads to a set of additions of specialties to be added to the collection in My Hacienda.

It is taking us quite a while to build up that set of items, because at present we are the only ones working on it.

As a reminder for unregistered readers of this forum who may chance upon this post, My Hacienda is an attempt to visualize a set of 2750 small businesses which would combine to achieve and maintain a "first world" stand of living on Mars.

The number 2750 is arbitrary, arising as it does from the toss of a mental dart by Louis, who picked a location for Sagan City 2018 out of the thinnest of air.

However, I am pursuing it as a benchmark to try to answer the question of what is the minimal number of people and knowledge specialties that would be needed to achieve and to maintain a high order of civilization in a location remote from Earth.

Edit#1: For SpaceNut ... added to My Hacienda PlotMaster:
0054 Air quality vendor #1 This specialization is common on Earth as Heating and Air Conditioning (HVAC) Heating Ventilation Air Conditioning
0055 Air quality vender #2 The vendors is this set will compete with each other to serve residential and commercial customers
0056 Air quality vender #3 Technology on offer will include passive and dynamic air cleaning and preparation methods

(th)

Last edited by tahanson43206 (2020-06-22 08:01:16)

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#504 2020-06-22 16:44:26

SpaceNut
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Re: International Space Station (ISS / Alpha)

The out gassing is critical for detection in any closed habitat space that can not take in new resources and must filter those with in them to keep people safe. This is one of the self sustaining limits for all whom would in habitat the My hacienda plots...
As for providing a pipeline or bottled air for that purpose that's going to be more than one in time for competition such as some of the other plots identify in the registry.
As far as the plot registry size there is no doubt that it can become huge for the topic and even when the majority of business are repeated from the start anywhere from 2 to 4 times to divide into that initial 7800 plots we still end up with a minimum of 1900 plus to 3,900 unique plots to be had.

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#506 2020-08-16 09:12:38

SpaceNut
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Re: International Space Station (ISS / Alpha)

contains many robot/robotics

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#507 2020-08-27 17:06:00

SpaceNut
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Re: International Space Station (ISS / Alpha)

Russia’s Nauka ISS module arrives at Baikonur for final launch preparations

NSF-2019-07-03-18-58-35-800.jpg

Prichal features six docking ports – one of which will be used to connect it to Nauka.

The module’s launch – which has been delayed for more than 13 years – will mark the resumption of Station expansion.

Nauka is currently scheduled to launch on a Proton-M rocket in April 2021 and will be attached to the ISS at the location where the Pirs Docking Compartment is currently located. The module that would become Nauka – Russian for “Science” – was first constructed as the backup to the currently-on-orbit Zarya module.

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#508 2020-09-07 19:27:13

SpaceNut
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Re: International Space Station (ISS / Alpha)

tahanson43206 wrote:

For SpaceNut ... here is an item encouraging for human space flight, ** and ** for humans on Earth ...

The work is in early stages, and much more needs to be done, but it appears that an experimental treatment was successful in overcoming damage normally caused by weightless conditions ...

https://www.yahoo.com/news/mighty-mice- … 17778.html

The report is  by Marcia Dunn, whose work is generally well regarded.

(th)

Mice been used to aid in order to treat the issues of microgravity.

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#509 2020-09-19 17:35:39

SpaceNut
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Re: International Space Station (ISS / Alpha)

This is part of the cooling system and is external to the modules
https://www.spacedaily.com/reports/Smal … S_999.html

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#510 2020-09-25 19:08:12

SpaceNut
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Re: International Space Station (ISS / Alpha)

The station will be getting a new toilet for node 3 installation that is 65% smaller and with a 43% less mass for only a tiny little sum of 23 million.

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#511 2020-10-11 18:44:31

SpaceNut
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Re: International Space Station (ISS / Alpha)

Northrop Grumman launched its capsule to the International Space Station from the Virginia coast. A space station cargo ship is chasing after the International Space Station with a special food delivery Radish seeds, meats and cheeses

Stashed aboard the Cygnus capsule: pressurized air tanks to help offset a vexing leak at the space station, a new $23 million titanium toilet custom fit for women, packed in the  8,000-pound (3,600-kilogram) shipment.

Among the delicacies requested by the astronauts: proscuitto, Genoa salami, smoked Gouda and provolone, brie, cherry tomatoes, oranges, pecans and chocolate-covered cranberries in plenty of time for Thanksgiving.

Researchers are hoping for 40 radishes from the seeds going up, within a month. Larger plants like peppers and tomatoes should follow in a few years, adding to astronauts' diet.

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#512 2020-10-12 17:15:10

SpaceNut
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Re: International Space Station (ISS / Alpha)

modules are starting to show there age when ISS crew fails to resolve air leak issue in Russia's Zvezda Module with adhesive tape

zvezda-module-cutaway-marker-hg.jpg

A small air leak was detected in September 2019 on the ISS, and by August 2020, the leakage rate had increased five-fold - from 270 grams to 1.4 kilograms (9.5 ounces to 3 pounds) of air per day. The leak does not pose a risk to the crew.

Zvezda was launched on a Proton rocket on July 12, 2000, and docked with the Zarya module on July 26, 2000 allowing 2 crewmen to stay....

The station would need replacement modules before it losses certification aka expiration date...

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#513 2020-10-12 20:53:51

RobertDyck
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Re: International Space Station (ISS / Alpha)

They tried to seal it with adhesive tape? Is that Scotch tape or duct tape? Wouldn't that require special tape with adhesive that's air tight, and adheres to the metal of pressure hulls? And strong aluminum backing?

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#514 2020-10-13 06:24:17

tahanson43206
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Re: International Space Station (ISS / Alpha)

For RobertDyck re #513

The Russians are (apparently) in the embarrassing situation of having designed a module for the space environment that could not easily be analyzed for a leak.

Since the Russians have proven competent spacecraft designers over many decades, and leaks are rare, there may have been something special or unusual about the design of this particular module that led to its vulnerability.

However, their embarrassment is an opportunity for an up-and-coming spacecraft designer such as yourself to take to heart.  In the back of your mind as you imagine the components you will assemble into the working Large Ship ** could ** be the inevitability of leaks, and therefore the importance of designing for ease of location and repair.

One rule-of-thumb that occurs to me is to insure that every part of the vehicle can be dis-assembled while it is in use, in order to get at the outer skin, which could be punctured by a stray object at any time.  This is ** not ** something that the average home builder on Earth has to think about.

Now, before you've started making blueprints, is an ideal time to be thinking about this aspect of the design.

(th)

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#515 2020-10-13 08:47:18

GW Johnson
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Re: International Space Station (ISS / Alpha)

A while back,  one of the crew Soyuz capsules had a leak that turned out to be a drilled hole where one should not have been.  Whether this was a manufacturing error or sabotage was never made clear publicly,  and the news media quickly forgot that incident to death.

My guess is that this one is a fatigue crack somewhere,  in the aluminum pressure shell of the module.  They seem to know where it is,  if they tried to patch it with tape. 

Almost any sort of tape would work to one extent or another,  if applied to the inside of the pressure shell over the crack,  such that the air pressure acted to hold it in place.  A metal or plastic tape would work the best,  being impermeable to air.  But even paper masking tape would slow the leak,  if applied in this way.

The problem is getting to the leak.  Unless you can expose the pressure shell from the inside,  you cannot use the interior pressure to help seal your leak. If you try to use tape on the exterior of the pressure shell,  the pressure of the air acts to tear away your tape.  A tape repair on the outside will never really work,  because of that.

Nobody,  not the US,  not ESA,  not the Russians,  and I bet not the Chinese, design spacecraft hulls for accessibility to the inside of the pressure shell.  This is a lesson no one has yet learned,  except Bigelow,  and that was a happy accident of their design approach.  They don't mount equipment on the pressure shell,  it is mounted to an internal core structure.  And their thermal insulation/meteor bumper layers/radiation shielding is mounted on the exterior of their pressure shell,  which is a polymer-fabric composite,  not a metal,  since it is an inflatable.

This unlearned lesson will sooner-or-later become a catastrophic fatality.  Fatigue cracks,  left untreated,  grow.  If that crack in the shell grows far enough,  the pressure vessel WILL burst!  That is a sudden fatal depressurization accident for the entire ISS crew.  Taping the leak shut,  even from the inside,  does not stop crack growth!  The temperature swings day/night are what drive crack growth,  by thermal expansion effects.  It has nothing to do with pressure cycling.

Believe me,  this fatal accident will happen.  It did before,  with the DeHavilland Comet jet airliner in 1953-1954.  It took three planeloads lost in fuselage explosions over the Atlantic before the lessons of metal fatigue were learned.  Here it is facing us again,  this time in space.

To treat a fatigue crack,  you must find the ends of the crack (all of them!),  and drill them out to increase the effective radius of curvature.  That dramatically lowers the stress at the end of the crack,  stopping its propagation.  Then you can patch the pressure leak. 

But unless you can access the pressure vessel surface for inspection and work,  you cannot do any of this properly.  And you cannot do it in those bulky suits at all.  How do you hold a hand drill and use a 1/16-inch diameter bit accurately (!!!),  suited up like that?  Ain't gonna happen!  So you have do it,  in a shirtsleeve environment,  from the inside. 

I have yet to see a spacecraft (from anybody !!!) whose design would allow this.  Mounting equipment all over the inside of the pressure shell,  and putting all the insulation on the inside,  are the way they all do it.  That's a traditional holdover from the one-shot/throwaway days. 

And it is the wrong way to do this for routine operations. Just like the square-cornered windows in the DeHavilland Comet were wrong.  They didn't know any better back then,  until those 3 planes exploded in mid-flight.  We know better now!!  So there's no excuse.

GW

Last edited by GW Johnson (2020-10-13 11:45:54)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#516 2020-10-13 10:37:33

kbd512
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Re: International Space Station (ISS / Alpha)

GW,

I brought up this issue some time ago, regarding the importance of being able to weld on the hull to repair or replace it.  That's why we need to use Aluminum plates and bolts or rivets instead of welded sheet steel.  You can easily weld cracks in Aluminum.  You can still do it with steel, but it's more time consuming, requires more heat for a good weld, etc.  I had an idea a year or two back that used these new directional magnets, from a company named PolyMagnets, to secure things to the pressure hull, rather than having things bolted into place.  That would permit rapid un-bolting of computers / cargo / piping / wiring looms / etc, in order to rapidly get at the hull for repairs.  Anyway, we now have magnets that you can twist 90 degrees to "unlock" them, meaning two magnets that you rotate through 90 degrees in order to pry them apart.  It's a commercial product that is even used by small cranes to lift tons of materials, Grainger has this "MagSwitch" product listed for $50 to $500, dependent upon the strength / size of the magnets.  Anyone thinking about long duration space flight should really take up this idea.  They can call it their own idea, or call it the idea of the companies that invented these magnetic switches.  Either way, I just want the crew to be able to save their own bacon if something penetrates the hull.

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#517 2020-10-13 11:40:08

RobertDyck
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Re: International Space Station (ISS / Alpha)

The first crew Dragon had exposed aluminum pressure hull on the inside. You'll notice as flown there's some sort of white interior, presumably a plastic inside wall. So same problem with Dragon.

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#518 2020-10-13 12:00:29

GW Johnson
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Re: International Space Station (ISS / Alpha)

Hi Kbd512:

Hope you survived the heavy rains OK from those last 2 hurricanes.  We saw nothing up here in the regions around Waco. 

If you are going to use magnets (and they sound quite promising),  you'll have to physically attach them in some way.  Aluminum and stainless steel are not magnetic.  Both aluminum and the various steels are susceptible to fatigue cracking,  some worse than others.  Aluminum is by far the more susceptible to fatigue.  It is also the most common material used in aviation and spacecraft construction.

I know they say that composites are not susceptible to fatigue,  but I don't really believe it.  Not classical fatigue cracking like the metals,  but some sort of aging damage from repeated use.  Unlike the metals,  these composites are subject to weathering damage,  if nothing else.    I think it will show up as hard-to-detect internal delamination,  not a propagating crack.  The fibers in the composite stop crack propagation,  if they are laid up in the least correctly,  but they CANNOT stop delamination.  It'll probably show up at joints,  especially where fasteners are involved.

Hi RobertDyck:

I dunno exactly what I am looking at inside the Crew Dragon.  I suspect there are some sort of interior panels covering up the inside of the pressure shell.  Between the pressure hull and the outer "mold line" shell are both equipment and insulating materials,  that much I know.  And down near the base of the pressure shell,  that is where the propellant tanks for the thrusters are located. 

If there were a hull puncture on Dragon,  it is from the inside of the pressure shell that offers the only chance of a patch operation.  But whether this could be accomplished at all is quite unknown to me.  If it takes minutes to open those interior panels to expose the shell,  when you have only seconds before depressurization from a meteor or debris strike,  that is not a good combination.  It is likely fatal.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#519 2020-10-13 13:01:42

kbd512
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Re: International Space Station (ISS / Alpha)

GW,

We received a little bit of rain, but that was about it.  The magnets can be affixed into place by using a machined Aluminum tube with a flange or ridge machined inside of it.  The magnet will be placed behind the ridge, such that it's sandwiched between the tube's interior flange and the hull.  A slightly more sophisticated variant would be a "push-twist-lock" variant that has a bunch of empty locking cups (keyring type devices) cover the hull, but the magnetic locking blocks would only be positioned where required, to hold wiring looms or piping or equipment or consumables or personal belongings.  In the simplest form, the completed device would then be welded to the inside of the hull using conventional methods or friction stir.

Thereafter, whether the device affixed or locked into the hull is welded in place or twist-to-unlock removable (just like the magnetic clamp itself, but using the traditional keyring method), the connecting magnet can be twisted into the receiving cup using an interrupted screw thread, to bring the connecting magnet close to the magnet post affixed to the hull, whereupon another 90 degree twist will "lock" the magnet into place.

Come to think of it, you don't absolutely need magnets, but magnets welded to the hull would provide an encapsulated solution with no moving parts, meaning no friction rings and tension springs or other small parts (twist-to-unlock aircraft type fasteners that require screw drivers to remove).  We could then provide small "wrenches" or "drill chuck" type tools (a special type of Allen key by any other name) to provide the leverage required to unlock and remove the magnets to eliminate protrusions that could cause injury.

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#520 2020-10-14 18:51:18

SpaceNut
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Re: International Space Station (ISS / Alpha)

A trio of space travelers has launched successfully to the International Space Station, for the first time using a fast-track maneuver to reach the orbiting outpost in just three hours.
cosmonauts Anatoly Ivanishin and Ivan Vagner, as well as NASA astronaut Christopher Cassidy, brings the station crew to 6.....

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#521 2020-10-20 15:44:12

SpaceNut
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Re: International Space Station (ISS / Alpha)

https://en.wikipedia.org/wiki/Zvezda_(ISS_module)

ISS air leak repaired with help from floating tea leaves

A cosmonaut finally found the leak by releasing tea leaves to float freely in the station’s Russian side.

He saw them cluster near a crack on the wall. The crew has temporarily patched the leak with tape, but it may not hold for long.

Sounds like metal fatigue.

The orbital lab's first module was launched over two decades ago in 1998 and there have been growing concerns about its age.

Russia pressing forward on ISS expansion Jul 03, 2019 · The third new Russian module is the Science-Power Module-1 – also known as SPM-1 or NEM-1

5ecba2272030271def67c35c.jpg

maybe if the station is to stay then it time to look at a launchable replacement module
https://en.wikipedia.org/wiki/Interim_Control_Module

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#522 2020-10-21 14:27:59

GW Johnson
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From: McGregor, Texas USA
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Re: International Space Station (ISS / Alpha)

"near a crack on the wall"
"sounds like metal fatigue"

Toldja so,  didn't I?  In post 515 just above!

It's the day / night temperature swings that are the cycling mechanism.  The stresses change due to thermal expansion and contraction.  This is markedly worse if your pressure shell is the outside surface with the insulation on the inside,  but it happens if the pressure shell is inside insulation that is not massively thick. 

Depends upon what kind of tape we are talking about,  as to whether it will stick permanently or not.  The descriptions indicate the pressure shell is exposed on the inside where the cosmonauts could see it,  and could patch it with that tape. 

You'd like the super adhesive that is on Gorilla tape,  but you'd also like the impermeability of an aluminum tape.  Why not put a patch over the crack of Gorilla tape,  and then cover that with a second layer of aluminum tape?  Depends upon what they have on board,  but we can always ship up better choices later.

The problem with the tape repair is that no one drilled out the ends of the fatigue crack.  So,  it will continue propagating,  at both ends,  too!  You have to drill out the crack ends to stop future propagation.  That requires some sort of magnifier to see exactly where to drill,  and a precision means to position the drill.  Only a small drill bit is needed.  I suggested 1/16th-inch,  but it could be half that. 

When you drill,  it will leak a lot more,  until you put the patch over the hole.  That is inevitable.  So you work fast,  and your backup is to abandon and seal off the module. There is no way around that.  Unless you can work bare-handed in vacuum.

But wait,  there's a way to do that,  for up to about half an hour at a time!

If you had a supple MCP suit made of separate pieces,  you could still do this inside a depressurized module,  because nothing is too hot or too cold to touch,  and you need no gloves for up to half an hour.  No bulky insulated outer wear is needed,  just the vacuum-protective underwear,  and the oxygen breathing helmet.

Now do you see why what Dr. Webb did toward multi-piece MCP in the late 1960's makes so more sense than what Dr. Newman did with one-piece MCP at MIT?  Dr. Webb's approach was basically vacuum-protective underwear.  Dr. Newman's approach was an all-in-one garment for EVA only.  EVA-only IS NOT the threat here with module pressure leaks.

The real world is a bitch,  ain't it?

GW

Last edited by GW Johnson (2020-10-21 14:32:22)


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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#523 2020-10-21 19:31:23

SpaceNut
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Re: International Space Station (ISS / Alpha)

The drill size sounds about right. Put a cordless drill inside a taped down bag to limit the out going air and to mitigate the pieces of metal from getting lose while drilling. Put pieces of tape on the inside to make a sticky location for the metal to collect onto. Now to fill the crack and hole is the issues as its got to be quick setting. An adhesive that hardens with UV might work temporarily but realistically we need to weld the area and the weld a buckle band  or plate over that to reinforce the area.

.

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#524 2020-10-22 08:58:54

GW Johnson
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From: McGregor, Texas USA
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Re: International Space Station (ISS / Alpha)

I'm skeptical of welding repairs to cracks in aluminum spacecraft pressure shells for two very compelling reasons.  (1) The ability to successfully weld paper-thin aluminum sheet is not a common welding skill.  (2) No one who does have this skill welds aluminum with a pressure difference across it (weld puddle blows out into space),  so it would have to be done (while space-suited) with the space depressurized.

I did know one (out of hundreds) of welders who could weld back together a Coors beer can after cutting it in half.  That's a very low percentage.  Very low indeed.  That is the skill level we are discussing here.

No one has ever tried welding in vacuum,  excepting only electron-beam welding in vacuo to make rocket motor cases.  That's the only vacuum welding process I ever heard of.  As far as I know,  any sort of stick or wire-feed welding done with a pressure difference across the workpiece will always blow the weld puddle out to the low pressure side.  That would be true for any material,  not just aluminum.  Liquids always flow in the direction of deceasing pressure. It's just physics.

So if you depressurize to make the weld repair,  how do you NOT compromise the skill when wearing a space suit?  Especially with the clunky suits we have now.

GW


GW Johnson
McGregor,  Texas

"There is nothing as expensive as a dead crew,  especially one dead from a bad management decision"

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