[HN Gopher] One hull crack located in ISS, another one suspected
___________________________________________________________________
One hull crack located in ISS, another one suspected
Author : revicon
Score : 379 points
Date : 2021-01-22 22:24 UTC (1 days ago)
(HTM) web link (tass.com)
(TXT) w3m dump (tass.com)
| keyle wrote:
| I burst into laughter reading the Russian's quotes. I love how
| casual the astronaut is about it!
|
| I'm no astronaut but I wouldn't be sleeping with crack in my
| hull, leaking air.
| lolc wrote:
| After fixing that leak they can go back to sleeping among
| uncharted fragments that can collide with no warning but
| catastrophic impact.
| calcifer wrote:
| They leak 0.3 mmHg _per day_ and are currently at 750 mmHg. An
| emergency is 0.5-1 mmHg _per minute_. They really don 't have
| anything urgent to worry about.
| faeyanpiraat wrote:
| Ok, so it's a 4.5cm long crack.
|
| If an aluminum bycicle frame cracks like that, it is useful
| to drill holes at the end of the cracks, to stop the cracks
| from progressing.
| curiousllama wrote:
| Except loud cracking sounds followed by a gentle breeze
| sellyme wrote:
| If they're experiencing a breeze they might have bigger
| problems to worry about than a cracked hull.
| segfaultbuserr wrote:
| > _He underscored that air loss due to the crack are
| insignificant. "This leak is like as if you'd drill the hull
| with a 0.2 mm diameter drill. I'm not sure such drills even
| exist in household. _
|
| I had to check my collection of PCB drill bits when I was
| reading it, and yes, I confirm that I'm a proud owner of a 0.2
| mm drill at home, it was the smallest one in the box ;-)
| nosianu wrote:
| The existence of a drill is no guarantee that you can
| actually create a hole. I once was a battle tank maintenance
| guy and we had to replace a cover placed in front of the
| armor. The replacement had holes in different positions, no
| problem, just drill a new hole, right? An hour and a few
| broken drills later we gave up. No doubt there are drills
| that work on that armor-steel, my point is, depending on the
| material just _any_ drill may not be good enough. An hour of
| hard work barely caused a <0.5mm "deep" scratch to appear!
| PS: We solved the problem by not solving it. Attaching three
| points instead of four was enough, de decided. That tank
| would never see a real battle but was only used for training
| anyway.
| HeyLaughingBoy wrote:
| True. But if it's a PCB drill as (s)he said, then it's
| likely either solid carbide or has a carbide tip. Hold
| everything rigidly enough and run that drill at the right
| speed and feed rate, and there's a good chance that it will
| drill armor plate.
| segfaultbuserr wrote:
| Full product catalog from the manufacturer if anyone's
| interested:
|
| https://www.uniontool.co.jp/assets/pdf/catalog/drill_rout
| er2...
| TomK32 wrote:
| still unused?
| segfaultbuserr wrote:
| Still unused. The smallest bit I've used is a 0.8 mm one.
| Anything smaller, it's impossible to even see where you are
| going without a microscope.
| ortusdux wrote:
| What are there reserves like? How long could they sustain a 0.5 -
| 1.0 mmHg / min leak?
| csours wrote:
| I wonder what that means in grams/min
| throwanem wrote:
| You'd have to take the derivative with respect to time, I'd
| think, because the ejection rate might decrease with
| pressure.
|
| Instantaneously, with a 1mmHg/min leak I think you'd lose
| roughly 1.5kg or a little over a cubic meter's worth in the
| first minute, given the 915.6 m^3 pressurized volume and a
| mass of ~1.3kg/m^3 for air at sea level (760mmHg, which is
| close enough). How long it takes to get down to an
| unsurvivable ~250mmHg (assuming an Earth-air-like breathing
| gas aboard ISS, which seems reasonable) takes more trouble to
| figure out than I care to go to on a Friday night, but the
| lowest possible bound (assuming a constant ejection rate)
| would be somewhere around 500 minutes, or between eight and a
| bit to nine-ish hours.
|
| Honestly I'm more curious what area a breach would have to
| have to produce that kind of leak rate.
|
| _edit:_ Actually, given the effectively infinite volume at
| effective vacuum outside the hull, you wouldn 't see the same
| "counterpressure" effect you would in atmosphere, that causes
| pressure equalization to slow down as it approaches equality
| - there's no _equalization_ that can happen here. That said,
| you 'd still lose less mass per unit time over time, as the
| internal pressure and thus the mass per unit volume drops.
| xxpor wrote:
| Are Tass articles always translated this poorly? I'm just
| surprised that a state owned news agency would put something like
| this out.
| tempestn wrote:
| Are you sure it was a translation? I assumed it was quoting
| Solovyov speaking English.
| meepmorp wrote:
| The article is reporting an interview that happened on
| Russian state TV, so it's almost certainly a translation.
| xxpor wrote:
| It's not even the interview that's the issue, the actual text
| the author wrote is a mess too.
|
| >He underscored that air loss due to the crack are
| insignificant.
|
| >In November, Russian cosmonauts photographed the suspected
| leak location on the outside of the ISS, but found no hull
| damage at where the crack is supposed to be.
|
| Granted, it's understandable, but it sounds like someone who
| learned English in school but never really uses it rather
| than someone paid to translate.
| shard wrote:
| I tried to make the two sentences grammatically correct:
|
| >He underscored that _the_ air loss due to the crack are
| _is_ insignificant.
|
| >In November, Russian cosmonauts photographed the suspected
| leak location on the outside of the ISS, but found no hull
| damage at where the crack is supposed to be.
|
| These seem minor to me, compared with some horrific ad copy
| that I've seen, which mangled SVO order or used completely
| inappropriate terms. Articles and plurals are hard for non-
| native speakers whose mother tongue do not have them (not
| sure if Russian does or not), and prepositions require
| memorizing a large number of idioms.
| userbinator wrote:
| Yes, Russian has no articles. Omitted (or incorrect)
| a/an/the is one of the more distinctive signs of someone
| whose first language is Russian.
| sellyme wrote:
| I routinely see English errors far more egregious than that
| in publications written exclusively by native speakers, so
| I'm not sure it's too noteworthy.
| andrewpk wrote:
| https://media2.giphy.com/media/fADf4RUs3hUFvHz18o/giphy.gif?...
| badRNG wrote:
| I don't often upvote memes on this site... but this got an
| audible laugh out of me
| arthurcolle wrote:
| Can they duct tape it from outside?
| codesnik wrote:
| from inside should be better for actually keeping air from
| leaking. I wonder why it isn't working 100% well
| arthurcolle wrote:
| Doesn't that depend on how the crack is forming, from outside
| or from inside? Gosh, can you imagine being in space and
| knowing there's a crack? I'd be so stressed. But the Russian
| dude said that the integrity is within acceptable limits or
| something, so I guess they can just do some calculations and
| feel confident.
|
| Still, it must be intimidating to know that you are
| performing your own due diligence for the very fabric of your
| own life-support systems.
| artiscode wrote:
| I wonder if radiation will become an issue at some point. It is
| being irradiated all the time, doesn't it also start to leak
| inside? Can that be an issue in the future for inhabitable
| objects in space?
| forgotmypw77 wrote:
| i think we,re kidding ourselves about human space exploration.
| machines are taking over and soon they,ll be able to do it
| autonomously or near so. we,ll be stuck on earth for a good
| while... with this biome we,re so intent on wiping out right
| now
| socram2k wrote:
| Revolving the earth each 90min, with the changes in the amount
| of energy received by the sun in each cycle has to be very
| stressful for a metal frame.
| NickNameNick wrote:
| That depends on what you mean by radiation, and 'leak inside'
|
| On the ground, most radiation 'leaks' are mostly chemical
| contamination problems.
|
| In space the volume of free material, and the pressure gradient
| should prevent anything outside coming in. Except perhaps on
| the exposed surfaces of the airlocks/docking adapters.
|
| Come types of particle radiation might cause
| transmutation/activiation of the hull material - that could be
| a concern. I doubt it's major issue.
| throwanem wrote:
| Suits can bring material in, and do. I forget if it was the
| "smell of space" or the "smell of the moon" they were talking
| about, but I remember reading that one astronaut described
| the odor as like that of burnt gunpowder, and that suitborne
| particulates proved to be the source.
| mikro2nd wrote:
| I shudder to think what the _inside_ of those space suits
| must smell like...
| throwanem wrote:
| Yeah, Mike Mullane has a lot to say in his autobiography
| about the _earthier_ odors of spaceflight. Suits probably
| aren 't all that bad by comparison with what the Shuttle
| cabin got like near the end of a long mission, especially
| if the toilet was acting up - a circumstance I gather was
| regrettably less rare than might be imagined by the
| naive.
|
| It's something that science fiction doesn't really
| explore - jokes about Trek's near-total lack of sanitary
| fixtures aside, even self-consciously grittier fiction
| like the Expanse series seems generally very disinclined
| to go there. I understand why, but that doesn't stop me
| thinking it'd be fun to see some hard-sf author really
| get into the weeds of why and how space makes something
| as elementary as the cleanly voiding of bodily waste into
| a surprisingly complex and difficult engineering problem.
| dotancohen wrote:
| > I shudder to think what the inside of those space
| > suits must smell like...
|
| Depends.
| richardwhiuk wrote:
| All radiation that you care about on the space station will
| be electro-magnetic - i.e. gamma rays.
| aero-glide2 wrote:
| It is supposed to be retired in 2024. But politicians will push
| it to 2030 so that ISS contractors keep getting paid.
| jpgvm wrote:
| Maybe with Starship flying soon we can replace the station for
| a fraction of what originally cost. I hope they consider
| pushing it out into a stable orbit instead of deorbitting it
| though... it seems like such a sad thing to destroy a piece of
| space history forever that we could feasibly retain now mass to
| orbit is orders of magnitude cheaper.
| walrus01 wrote:
| As a person that's previously owned a Zodiac-type boat, I really
| wonder what an ISS patch kit looks like.
|
| What sort of adhesives, covering materials, chemicals and
| application stuff do they have on hand for quick "we need to stop
| air escaping through this hole NOW" type situations?
|
| Obviously the problem is sort of reversed, if you have a leaky
| zodiac you're patching it from the outside and trying to stop air
| escaping into the atmosphere. If you have a leaky ISS module
| you're inside it, and applying some sort of quick-setting
| malleable chemical goop into a hole that's sucking your air
| outwards...
| spike021 wrote:
| Not a big space person, but this makes me wonder: why have we not
| planned for a new ISS? We must have better tech nowadays from all
| the working countries/groups currently involved, plus SpaceX and
| other space companies' backing that would not have existed as it
| does now back when this ISS was first designed/created.
| input_sh wrote:
| We do have plans for its replacement. Axiom is going to launch
| three modules, starting from 2024. When it's time to retire ISS
| (2028 probably), Axiom's modules will detach, effectively
| becoming ISS 2.0.
|
| I'm fine with ISS being open for commercial operations, but
| can't help but feel unease by the entire ISS being a commercial
| endeavour. But then again, about a fifth of NASA's budget goes
| to keeping the lights on in ISS.
| rtkwe wrote:
| I'll believe it when there's more than renders or they've
| booked a rocket. The current decomm date floating around for
| the ISS is 2025 so they're not long left.
| stefan_ wrote:
| Because the scientific value is dubious. Most of the
| experiments tend to be "doing X, but in space" or looking for
| solutions to medical problems that only occur because you are
| on the ISS on the first place.
| renewiltord wrote:
| When Starship comes online, building a thing like this will be
| hecka fast.
| qayxc wrote:
| Nope - there'll be not much difference.
|
| It's not just the getting things into space that's the hard
| and costly part. Modules take years to design, build, and
| test.
|
| That's why the current trend moves towards ever smaller and
| thus cheaper satellites and big launchers like Delta IV
| Heavy, Ariane 5, and Falcon Heavy barely see any action at
| all.
|
| Starship would enable single-launch space stations, yes. But
| there are no single-launch space station designs yet and
| building one will either take time (ISS/MIR) or end up being
| much more expensive per person day due to weak design (e.g.
| Skylab).
| desine wrote:
| It's a self-feeding culture. Launches were expensive, so
| you designed your spacecraft very thoroughly for many years
| before sending it up. If launches have become cheap, in
| part due to iterative design processes and letting oneself
| fail, then the same techniques can be applied to orbiting
| bodies. Launch a bunch of cheap inflatable labs, test them
| in real (out of) world conditions, and iterate towards a
| final design faster
| enraged_camel wrote:
| >> It's not just the getting things into space that's the
| hard and costly part. Modules take years to design, build,
| and test.
|
| Using the traditional approach, yes. But SpaceX is proving
| that there are other approaches that yield fruit far faster
| and also for drastically less money.
| qayxc wrote:
| Well, how many space stations have SpaceX designed so
| far?
|
| And what, pray tell, is the "traditional approach" in
| designing space stations compared to magical "approaches
| that yield results faster"? Are you aware that Skylab was
| designed, built, and launched in under 4 years and
| consisted of a converted Saturn-IVB rocket stage?
|
| The total program cost was $275M per year over 8 years
| (including design, 4 stations, 4 Skylab- and 3 Apollo
| launches, as well as operations), which translates to
| $1.6Bn/yr in 2021 dollars.
|
| Today, Bigelow Aerospace would have - maybe (they're
| currently defunct due to the pandemic - the B330 more or
| less ready to fly, but that is launched on an Atlas V.
|
| It took two demonstration models, launched in 2005 and
| 2007 to get them ready for prime time. In 2013 they
| developed the BEAM module under a 16 month NASA contract,
| which was launched and attached to the ISS in 2016.
|
| So BA built and deployed two prototypes in 2 years and a
| crewed fully functional module in 16 months with just
| $17.8M. Yet you assume that SpaceX, who never built a
| space station before, can somehow do it even faster and
| cheaper? Why? On what factual basis and on which
| historical examples do you base this assumption on?
| kiba wrote:
| _So BA built and deployed two prototypes in 2 years and a
| crewed fully functional module in 16 months with just
| $17.8M. Yet you assume that SpaceX, who never built a
| space station before, can somehow do it even faster and
| cheaper? Why? On what factual basis and on which
| historical examples do you base this assumption on?_
|
| Why not? The ISS is a spacecraft in all but name. It
| wouldn't be strange if they decided to use starship as a
| space station development platform, since they already
| planned for starship to carry humans to Mars.
| rurounijones wrote:
| > And what, pray tell, is the "traditional approach" in
| designing space stations compared to magical "approaches
| that yield results faster"?
|
| Well, the first thing that comes to mind is the huge
| amount of work done to keep things light, thin, self-
| contained and fit within existing payload bay sizes and
| can be constructed with minimum number of launches.
|
| If launch costs drop through the floor there is less need
| for that.
|
| You could build heavier, more robust stations because
| mass to orbit prices are so low. You could build it
| without having to minimise the number of launches. You
| could have much bigger and heavier sections sent up in
| pieces and built "on-site" so to speak.
|
| Much easier to consider when the price to move those
| heavy components up to space orders of magnitude cheaper
| and launches take place daily / weekly.
|
| (Yes I know I am glossing over a lot of things here).
| danielheath wrote:
| Yes, but there's a good reason why they have so-far
| reserved this approach for unmanned vehicles.
| hindsightbias wrote:
| NASA had no vehicle for launching a replacement. It didn't even
| have a domestic vehicle for launching astronauts for 9 years.
| SLS ate up any funds that were left.
|
| Private industry doesn't need a station.
| snoshy wrote:
| Largely because it's a fantastically expensive undertaking, and
| hasn't quite borne out the fruits that were speculated about
| over the years. USA provides a huge bulk of the funding,
| expertise, and personnel required to keep the program running.
| That's not to say that Russia, Canada, Japan, etc. don't do
| their part, but it's really not as much of a truly global joint
| effort as you might be led to believe.
|
| Then there's a genuine question of what this enormous
| expenditure truly buys us. NASA's budget has been strangled for
| decades now, and robotic probes and missions to other planets
| have been perennially delayed due to cost, while their
| scientific ROI would truly be much greater than for ISS
| experiments in many cases. Don't get me wrong, I'm a huge fan
| of the ISS and manned spaceflight in general, but this kind of
| money does require serious explanation to Congress to justify
| the costs. Oh, and there's the entire money pit that is
| Artemis/SLS that stays on NASA books.
|
| Also, why now? The private space industry is at what seems to
| be the beginning of an inflection point with heavy launch
| capabilities (SpaceX Starship) looking likely to drive down
| costs by over an order of magnitude. A single Starship might
| provide 800 cubic meters of volume, and the whole ISS is 1,000
| cubic meters. Why not wait for that to come online and then
| launch many many ISS' worth of volume to several labs?
|
| Lastly, the privatization of launch vehicles in particular has
| a lot of people questioning if private industry might be better
| able to step up to this challenge of manned orbiting labs. It
| has a potential to expand the range of solutions, massively
| decrease costs, and provide efficiencies that NASA might not be
| able to provide. When you don't have to manufacture space parts
| scattered all across the globe, it's easy to see why this could
| be cheaper and more efficient.
| mikro2nd wrote:
| The program might not have borne all the speculative fruits,
| but the one _very_ major thing that has come out of it is the
| learning about the effects of living in micro-gravity on the
| human body. If ever we want to get humans out into the rest
| of the solar system, this knowledge is priceless. Oh, I know
| that NASA has this constant pressure to justify that learning
| in terms of stuff like "medical benefits" (and there surely
| are a bunch of those!) but really it's the foundational pure
| science that's critical here. I don't think there's any
| monetary value can be put on that.
| jjcon wrote:
| > NASA's budget has been strangled for decades now
|
| It's higher than it was in the 70s and has remained pretty
| constant since then trending upward (when adjusting for
| inflation)
|
| http://static1.squarespace.com/static/500caca8e4b0e4a25027aa.
| ..
| mkl wrote:
| Yes. But in another way to look at it, as a percentage of
| the US federal budget, in 2017 and 2019 it was the lowest
| it's been since 1959.
| https://en.wikipedia.org/wiki/Budget_of_NASA
| jjcon wrote:
| As there continue to be more and more federal programs
| that will pretty much be the case for any individual
| portion of the federal budget - smaller proportionally
| but larger over all - so that really doesn't say anything
| calibas wrote:
| >Then there's a genuine question of what this enormous
| expenditure truly buys us.
|
| It helps to answer the question of whether or not humans can
| even survive long term away from Earth. Sure, if you judge it
| purely by the price tag, it's not doing very well. If you
| judge it by the scientific, societal and philosophical
| implications, we're not spending nearly enough.
| VWWHFSfQ wrote:
| > if you judge it purely by the price tag, it's not doing
| very well.
|
| This is a bad time for the ISS program to ask for more
| money. The USA Congress is not going to give NASA and the
| ISS program more money when they've already committed to
| print an enormous amount of dollars for COVID stimulus and
| various other COVID-related bailouts. NASA and the ISS is
| going to be on a budget for awhile. Even moreso than they
| were before.
| YetAnotherNick wrote:
| > It helps to answer the question of whether or not humans
| can even survive long term away from Earth
|
| How will it answer that question that we already don't know
| of? I don't think that was the aim of ISS anyways and will
| definitely won't be the aim of second ISS. Humans can
| survive in space for year without significant physical
| damage but with lot of training.
| calibas wrote:
| To me, it's just so odd that people don't seem to
| understand why we have an ISS. Is the main argument
| "We've already learned what's needed about life in space,
| and now we don't need a space station anymore"? That
| seems absurd.
| lordlic wrote:
| No, the argument is that there's plenty to learn, and
| it's all very interesting, but it doesn't stand up
| against people's very real needs here on Earth. I'm about
| the biggest fan of space you'll find, but even I, sadly,
| find the ethical calculus unassailable. Manned
| spaceflight won't accrue material benefits for ten
| generations or much more, and meanwhile human beings are
| dying of treatable or curable diseases, suffering under
| poverty, and living without access to clean water.
|
| This spoken-word work from 1970 conveys the sentiment
| well: https://www.youtube.com/watch?v=goh2x_G0ct4
| perl4ever wrote:
| >I'm about the biggest fan of space you'll find, but even
| I, sadly, find the ethical calculus unassailable.
|
| I'm not the biggest fan of manned spaceflight, and I
| couldn't care less about the ISS in particular.
|
| But how does "ethical calculus" tell you to care about
| killing the ISS, vs. say LIGO, or wasteful military
| spending, or the video game industry, or foie gras, or
| goldschlager, or TikTok or astronomy in general or the
| Xbox or selfie sticks or...
|
| If I was dictator, I'd prefer missions like New Horizons,
| but I can't see what ethical calculation is involved, I'd
| just rather see pictures of far away stuff than pay taxes
| for a space station to go around in circles.
| bluGill wrote:
| The ISS exists to give Russia cover to keep the ex Soviet
| rocket scientists employed and thus not tempted to work
| for some evil dictatorship.
| onethought wrote:
| The problem with Privatised space industry is your country
| doesn't control the agenda. SpaceX is a pretty rare thing,
| the rest of the private space industry (Blue Origin, Virgin,
| Boeing) is as much of a money pit as NASA was.
|
| Then you have rapidly progressing government run space
| programs like China and India. The fact that the US banned
| China from the ISS and banned Non-Americans from
| participating in what it deems as weapon systems has only
| driven more resolve for home grown/soveraign alternatives.
| snoshy wrote:
| Echoing the sister comment to add more color, I think when
| it comes to this scale of money, it becomes too easy to
| conflate public and private capability. The ISS cost $150
| billion. That is a kind of cost that even the tech
| behemoths of the world today would not be able to stomach.
| Some efforts really require country-coffer levels of money
| to be realized.
|
| That means the US government directly controls which
| projects live and die, simply because they control the
| purse. Most space endeavors don't require this scale of
| money, and even a small token of innovation incentives can
| often result in outsized societal benefits. Even for SpaceX
| to just think about the Starship program, they literally
| had to corner the global orbital launch market for nearly a
| decade to come.
|
| While I do agree that Boeing is a money-pit due to their
| involvement with SLS, I still wouldn't put Virgin or Blue
| Origin in anywhere close to that bucket. While these two
| might not be as incredibly innovative and capital efficient
| as SpaceX, they're still orders of magnitude better than
| anything like the SLS, Boeing, Lockheed Martin, and others
| that are considered "old space".
|
| China is pouring an absurd amount of its own money through
| thinly guised military development arms, and they're
| excelling at it. It's truly a shame that the US cut them
| off from the ISS, and its even more detrimental that the
| rest of the world has not paid close enough attention to
| their efforts. They're about the only player that's even
| close to competing with anything like SpaceX.
|
| I wouldn't put India in the same club as China either.
| India has done extremely well at making cheap reliable
| orbital class launch vehicles by cost cutting and
| incremental improvements. Once SpaceX comes to the scene,
| they will be obsolete. They do not have the public appetite
| to invest the scale of money required to build programs the
| likes of US & China can build.
|
| Russia meanwhile seems obsessed with trampolines.
| blackrock wrote:
| China finally have their own heavy lift rockets, the Long
| March 5B. This gives them the ability to finally launch a
| Mir-like space station, which they will start assembling
| this year.
|
| The 5B also gives them more options.
|
| In 10 years, when they complete their own Super Heavy
| Lift rocket, the Long March 9, of Saturn V class, then
| things will get interesting. It seems like they will ace
| this one as well. This can help them send human missions
| to the moon.
|
| But the interesting developments, are their space plane
| research. Which they started back in 2006, and estimated
| it would take 15 years, and would require a heavy lift
| rocket, the 5B, which they now have. This would put it
| around the 2021 time frame, which is now. And last year,
| they successfully tested their secret space plane
| prototype. If they scale up their space plane, and enable
| it to transport humans too, then they'll have an
| interesting mechanism to transport their astronauts to
| their space station, and return them gracefully back to
| the earth.
|
| Then, it seems they will succeed with their Long March
| 8R, for reusable vertical take off and vertical landing,
| similar to SpaceX. It seems they will be the 2nd
| organization, after SpaceX, to achieve an operational
| VTVL system.
|
| I figured, if they can robotically stick the moon landing
| in a vacuum, using retroactive propulsion, then they can
| probably land a reusable booster back on earth.
| onethought wrote:
| China is more crazy because SpaceX got access to Nasa
| research and development (through people and location)...
| China have kind of home grown there whole system in an
| insanely short time
| tachyonbeam wrote:
| Electron Labs are a successful competitor to SpaceX in the
| satellite launch space. They don't have the same
| capabilities, but they are much more cost effective than
| Boeing. Virgin Orbit also just successfully launched a
| satellite with a rocket attached to an airplane. I think
| it's possible we could see more serious competitors to
| SpaceX given enough time.
| onethought wrote:
| You mean Rocket Labs? - yes agree they have a similar
| innovation culture to spaceX (from the outside)
| curiousllama wrote:
| > you don't control the agenda
|
| True, but not really in the way you describe. The US is the
| main (often, the only) customer of US space companies. If
| you control the money, you control the operational agenda.
| If you want a a new ISS? Just write up the contract.
|
| The way in which you don't control the agenda is only
| inasmuch as the strategic interests of the space company
| diverges from those of the US govt. But typically, with
| outsourced high-value work, vendors will evolve to MORE
| closely align to their big customers. (It screws the small
| customers often, but hey, the govt isn't small).
|
| The issue in my mind is much more value extraction &
| leverage, but as long as there's multiple players
| (including an in-sourced option), I don't see how it's a
| problem.
| lordlic wrote:
| Gigadollar-scale space projects seem like a particularly
| poor fit for the private industry model, though.
| Conventionally the idea of free-market competition is
| that companies stand to gain if they succeed but have to
| eat the losses if they fail, and so competition
| eventually selects the best. But we're not talking about
| making widgets or sandwiches or launch vehicles. Things
| like the ISS, JWST, etc are _all_ one-off projects, and
| they _cannot_ be allowed to fail, so competition doesn 't
| really help and the public is left holding the bag, just
| like we see in the endless cost overruns of politically
| unkillable DoD contracts.
|
| "Public bad private good" isn't a coherent strategy. If
| NASA isn't good enough then the preference should be to
| improve NASA rather than to insert an unnecessary layer
| of profit-taking for SpaceX or Boeing to do the same
| thing anyway.
| curiousllama wrote:
| >Things like the ISS, JWST, etc are all one-off projects,
| and they cannot be allowed to fail
|
| True
|
| > "Public bad private good" isn't a coherent strategy
|
| Also true
|
| Still, an infinite series of one-off projects comprise a
| continuous market. If SpaceX royally screws up one
| project, then yes, the public is left holding the bag _on
| that project_. But you know who's getting a lot fewer
| projects? SpaceX.
|
| A federal gov't monopoly isn't the answer, just as
| abolishing NASA isn't the answer. Both are good. But...
| SpaceX is proving they can launch cheaper, quicker, and
| just as safely - isn't that a thing worth encouraging?
| onethought wrote:
| But space x work in spite of the nasa system... could you
| dream of nasa celebrating SN8 plowing into the ground as
| a raging success... it's a huge cultural shift, not so
| much driven by private sector competition (Honestly who
| competes with space x?), more to do with leadership
| style.
|
| BlueOrigin is a perfect Nasa 2.0 comparison.
| dotancohen wrote:
| > could you dream of nasa celebrating SN8 plowing into
| > the ground as a raging success.
|
| Nobody is celebrating SN8 plowing into the ground. We are
| celebrating the fact that SN8 plowed into the correct
| square meter of ground. We also celebrate the fact that
| SN8 plowed into that particular meter of ground while
| oriented in the direction that we hoped, but barely
| dreamed, that it would be oriented.
| onethought wrote:
| That's my point... I'm not saying space X is bad or
| irresponsible, they are just different (and I think in a
| good way). Agree SN8 was amazing! And something NASA
| would never have done. Nor would they livestream it, nor
| keep it available on their website.
| redis_mlc wrote:
| > SpaceX is proving they can launch cheaper, quicker, and
| just as safely - isn't that a thing worth encouraging?
|
| No because there isn't a launch demand large enough to
| justify what SpaceX is trying to perfect, and all of
| Musk's projects are welfare queens.
|
| HNers confuse the entertainment value of watching rockets
| get reused with actual space delivery - which is exactly
| backwards.
|
| If you're confused by the above, what is SpaceX going to
| do with their launch capacity after Starlink?
| saalweachter wrote:
| The ISS is modular.
|
| There's no need for a "new" ISS, _per se_. You just attach new
| modules and, if need be, detach and deorbit old modules.
|
| It's less exciting, kind of like maintaining an old code base.
| fuoqi wrote:
| There are plans on the Russian side. If it will be decided to
| discontinue ISS after 2026, then the new Russian modules
| (Nauka, Prichal, and SPM-1) will be undocked to form core of a
| new station. Depending on negotiations it could either become
| ISS-2, or sovereign OPSEK [0]. But unfortunately I don't have
| high hopes for those plans to be implemented in reality for a
| number of reasons.
|
| [0]:
| https://en.wikipedia.org/wiki/Orbital_Piloted_Assembly_and_E...
| spiritplumber wrote:
| The ISS mostly happened because it was a way to keep ex-Soviet
| aerospace scientists and engineers doing aerospace things
| rather than, say, go build ICBMs for third world countries.
|
| Same as Arecibo happened because the USAF wanted a big radar
| and the Hubble happened because (I forgot which spy agency it
| was) had a spare satellite.
|
| Sad when you think about it...
| HPsquared wrote:
| Satellites in general happened as a result of an arms race.
| rtkwe wrote:
| The space race at all was 90% a pissing match between the
| USSR and the USA.
| fuoqi wrote:
| >The ISS mostly happened because it was a way to keep ex-
| Soviet aerospace scientists and engineers doing aerospace
| things rather than, say, go build ICBMs for third world
| countries.
|
| Nope. It's funny you seriously consider it being true.
| Building space stations and ICBMs are two VERY different
| fields for one thing. And number of launches to ISS is
| significantly smaller than number of satellite launches.
|
| One of the main reasons for the US was a chance to buy space
| station building technology and transfer relevant expertise
| for a relatively cheap price tag. Russian/USSR scientists and
| engineers were far ahead in this field thanks to the Mir
| station. Creating a demand for the Space Shuttle was a good
| bonus as well.
| proggy wrote:
| Hubble's optics were designed around contemporary
| manufacturing infrastructure for spy satellites, presumably
| the KH-11 design developed by the National Reconnaissance
| Office (NRO) [1].
|
| [1] https://en.wikipedia.org/wiki/KH-11_Kennen
| adamjb wrote:
| Don't forget the other half of it: the ISS was basically the
| only justification for the Shuttle's continued existence
| philistine wrote:
| It's literally the most expensive single structure built in the
| history of our species. Perhaps this little fact can put in
| perspective why we have yet to plan for another one.
| ChuckMcM wrote:
| Materials aging in space is a pretty deep subject. That it is the
| Russian Zvevda module that is leaking/cracking is likely related
| to the fact that it is also the oldest module in the ISS.
|
| The ISS is/was scheduled to be retired in 2024 (aka 3 years from
| now) but there are calls to keep it going. My fantasy would be to
| have SpaceX move it into the Lunar L1 Lagrange point which would
| keep it in use but it would have to deal with more cosmic rays,
| also station keeping would be an issue unless we could really get
| energized tether station keeping to work (lots of solar energy to
| provide power, but not a lot of mass to provide thrust, so
| tethers are energized conductors that push against the Earth's
| magnetic field)
|
| Parking it in L4 or L5 could keep it for future generations but
| it would be even more of a challenge to go visit.
| stretchcat wrote:
| Are tidal forces a significant source of strain on the ISS, due
| to the size of the station putting different parts of it in
| slightly different orbits? And if so, would these forces be
| less at a lagrange point?
| jeffcox wrote:
| I realize their orbit is relatively clear of debris and micro
| meteors, but is this materials decomposing or degrading and not
| random damage and happenstance?
|
| The ISS has no doubt been important and I remember how excited
| I was when it was being assembled. Is it really so historically
| significant it's worth the amount of effort you're describing?
| thescriptkiddie wrote:
| Cracks are a common sign of metal fatigue, which can be
| caused by repeated stress cycles. Imagine bending a piece of
| plastic back and forth until it snaps.
| pengaru wrote:
| Especially for "cold butter" metals like aluminum and
| copper.
| ben_w wrote:
| I've never heard that phrase used in this content before.
| How does "cold butter" apply to these metals?
| pengaru wrote:
| I don't recall which of the many print books I read in my
| gearhead/TIG-welding days had used the term, but the lack
| of a distinct fatigue/endurance limit [0] for these
| metals was put into practical terms with something along
| the lines of "like slightly bending a cold stick of
| butter".
|
| It's why aluminum airplanes are supposed to get inspected
| for cracks regularly, and why aluminum bicycle frames
| must be so uncomfortably rigid. If there's cyclic stress
| occurring, it's a question of when, not if they will
| crack.
|
| If I had to guess it's from Carroll Smith's 80s-era
| Engineer to Win, it sounds like something he'd write.
|
| [0] https://en.wikipedia.org/wiki/File:S-N_curves.PNG
| fao_ wrote:
| I think it refers to the type of break the joint makes?
|
| However, while searching I found this search excerpt:
| Which metals diffuse into other metals and how? | Naked
| ... www.thenakedscientists.com > forum
| Sodium and potassium metal (both *soft solids, like cold
| butter*) react
|
| So perhaps it is used to designate 'soft solids' versus
| 'hard solids'
| lmilcin wrote:
| Hull is definitely not decomposing or degrading. If left in
| peace at sufficiently high altitude it would look the same in
| a million years.
|
| My bet is the issue is most likely stresses due to vibrations
| under pressure and pressure changes. It is complex but also
| well known problem. As the astro/kosmonauts move about the
| station, resupply dock, pressure changes, etc. some parts are
| being subject to constantly changing stresses while already
| being stressed due to pressure.
|
| It might also be possible that there are some additional
| thermal stresses but I think it is less likely these are
| source of the problem.
| Voloskaya wrote:
| > My bet is the issue is most likely stresses due to
| vibrations under pressure and pressure changes.
|
| So you are saying it's degrading?
| HPsquared wrote:
| Degradation of the structural integrity, I'd say.
| maxerickson wrote:
| These discussions about materials are often difficult,
| because there are meaningfully different processes that
| are lumped together in everyday language.
|
| Mechanical stresses leading to failure at a particular
| point are certainly a form of degradation, but I believe
| they mean degradation in the sense where the entire body
| of the material is undergoing some change (like a plastic
| bottle fogging or such).
|
| I think seeking clear descriptions is fine, treating it
| as a "gotcha" game is tedious and unnecessary.
| waheoo wrote:
| > "gotcha" game is tedious
|
| I agree but you can say the same thing in reverse. This
| is a public forums, you don't need to claim something
| isn't right because it doesn't fit the technical
| description.
| lmilcin wrote:
| Just stop this already.
|
| The post said "is this materials decomposing or
| degrading".
|
| While I may have not been precise about "degrading" part,
| we can assume the metal is definitely not "decomposing".
| waheoo wrote:
| Ah I think my reply went to the wrong person. Edit: Nope
| just under your comment is all.
|
| My remark is at the person claiming tit for tat about the
| tat instead of the tit.
| lmilcin wrote:
| I took liberty to look through the literature and it
| seems change of physical and chemical properties of
| material due to all types conditions (including physical
| stresses) is covered by the term.
|
| I am not into mechanical science that much, I have always
| treated degradation as a kind of surface or volume
| phenomena where the material looses its properties due to
| temperature, radiation, age, chemical reaction, etc. For
| mechanical effects there are already very good terms like
| metal fatigue and stress induced cracking.
| elihu wrote:
| > Is it really so historically significant it's worth the
| amount of effort you're describing?
|
| Space launches are getting a lot cheaper, so moving the ISS
| to another orbit might not be such a big deal as it used to
| be. We don't really need to keep the ISS around forever, but
| on the other hand, losing it would in some ways be similar to
| the burning of Notre Dame in 2019 (I can't believe that was
| less than two years ago). It's mankind's first permanent
| foothold in space. In that sense, it's irreplaceable.
|
| Let's say moving the ISS at the end of its usable lifespan
| costs a half billion dollars. That's like asking every U.S.
| taxpayer to pay about two dollars. Is it worth it? To me I
| think it's worth a lot more than two dollars, even if it
| unlikely that i'll ever actually be able to visit the ISS in
| my lifetime.
| jarofgreen wrote:
| > It's mankind's first permanent foothold in space.
|
| Mir?
| elihu wrote:
| Good point, I forgot about Mir. According to wikipedia it
| lasted from 1986 to 2001.
|
| I had briefly considered Skylab, but figured it didn't
| really count as "permanent". Wikipedia says it was up for
| 24 weeks.
| MisterTea wrote:
| > Parking it in L4 or L5 could keep it for future generations
| but it would be even more of a challenge to go visit.
|
| "If your planet has one or more broken down space stations on
| its lawn, you might be a redneck colony." (Sorry.)
| Waterluvian wrote:
| That's hilarious. Is that from anywhere beyond being a take
| on that one comedian's shtick?
| ipnon wrote:
| I imagine it's from a popular science fiction novel.
| Sargos wrote:
| It's just Jeff Foxworthy
| mycall wrote:
| American Astronaut or Stingray Sam is more apt.
| nitrogen wrote:
| Missed opportunity to replace "lawn" with "Lagrange"
| ves wrote:
| Alternatively, Lagrawnge
| codeulike wrote:
| Lawngrange
| fwipsy wrote:
| Lawngarage?
| lsllc wrote:
| I think we need a "Space New Deal", I'm honestly saddened by
| the lack of progress in space in my lifetime. I mean we've done
| some great work, but we haven't made any giant leaps since
| getting to the moon 51.5 years ago.
|
| Thankfully, we do have SpaceX et. al. who really are making
| some big strides -- but how do we multiply & speed up that
| effort? ... sorry, I'm being selfish, but I really want to go
| to Mars.
| waheoo wrote:
| That's what space force was wasn't it?
| godelski wrote:
| Space Force is specifically for military and not public. To
| protect strategic assets like keystone satellites, launch
| detection system, etc. Stuff the Air Force was doing but
| the sub department in the AF grew big enough that it became
| it's own thing. Similarly it's not unlikely to see a cyber
| force happen in the future.
| leptons wrote:
| TV and movies have sold you a fantasy.
| merpnderp wrote:
| Look at the SLS, how much money was spent, and how unlikely
| it is to ever do anything, and it looks like we aren't even
| capable of a Space New Deal if we wanted to.
|
| Luckily we have SpaceX.
| khuey wrote:
| Going to space is only a secondary goal for SLS though.
| Keeping a bunch of people in politically influential states
| and congressional districts employed is the primary goal
| and it's succeeding at that.
| WalterBright wrote:
| Government spending "creating jobs" is a lot like a
| business plan where you pay people to buy your products,
| or a car that makes its own fuel.
| khuey wrote:
| I'm not saying it's a _good_ goal but it is clearly the
| goal.
| iguy wrote:
| While I am horrified by the sums of money, I think
| there's a slightly less cynical take than the
| congressional districts one.
|
| If you want to have an industry of people who make X,
| then there need to be people employed making X, every
| year, for decades. And at more than one company, so that
| it isn't too fragile a career path. When X is single-use
| rockets there is the advantage that after one flight you
| have to re-build, whereas when X is tanks (or other long-
| lasting hardware) you have to choose to throw the old
| ones away.
| etaioinshrdlu wrote:
| Well, in the literal sense, the government can raise
| revenue via tax and employ people. So it's literally
| true... You might not like it, or it might be ill
| advised, or might believe that all taxation is theft, but
| it is what it is.
| merpnderp wrote:
| Money represents work, and the government is waisting
| billions of dollars of highly trained professional work
| hours on the SLS. This money could have been used in
| unaccountably more productive enterprises, but the
| incentive structures and feedback loops are so broken in
| government, it can't even build a rocket ship, in an era
| where every two bit backyard company is building their
| own.
|
| The taxes raised to pay for SLS actually are screwing
| over the rocket industry because companies actually
| getting things accomplished have to compete for the
| highly trained engineers and scientists being wasted on
| SLS. There's no amount of "trickle down theory" that
| makes the SLS a net gain for society.
| carapace wrote:
| > This money could have been used in unaccountably (
| _sic_ ) more productive enterprises
|
| The space industry is one of the major resource sinks
| that prevent runaway economic growth that would destroy
| civilization as we know it: the so-called "economic
| supernova".
|
| The natural result of scientific progress is a kind of
| economic _singularity_ beyond which is entirely unknown
| territory. What happens to our civilization when the
| primary underpinnings are obviated by technology? No one
| knows.
|
| So, NASA, FAANG, the Financial Industry, most of the
| lawyers, accountants, and bureaucrats, etc. are just
| make-work jobs to occupy productive people to keep them
| from inadvertently causing the apocalypse.
|
| (FWIW Bucky Fuller calculated that the inflection point
| to runaway wealth was in the mid-1970's. We're fifty
| years over due for the end of history.)
| JohnJamesRambo wrote:
| I've been watching a lot of documentaries about Mars and the
| more I learn the more it seems so incredibly daunting and
| overwhelming. The atmosphere isn't even thick enough to slow
| down properly from the massive speed you need to get there at
| a time scale that works.
|
| >The highest atmospheric density on Mars is equal to the
| density found 35 km above the Earth's surface.
| jldugger wrote:
| What do you think the fuel charge would be on a martian round
| trip?
| sgtnoodle wrote:
| Since there's virtually no drag between the planets, the
| distance doesn't linearly determine the amount of fuel.
| What matters is velocity changes. It's about 10km/s to get
| into orbit, and 5km/s or so to transit to Mars. Coming back
| is a lot easier because Mars has less gravity and
| atmosphere, and you don't need to bring as much stuff back.
| So maybe let's call it 20km/s total? Fuel has mass, so it
| takes fuel to bring fuel. If you were to bring all the fuel
| you needed along, it's probably going to end up being 5-10x
| the fuel for getting just to low earth orbit. Either you
| build one giant rocket, or more realistically you launch a
| few smaller rockets. Alternatively, if you can manufacture
| fuel on Mars, you only need to take along 15km/s worth of
| fuel. A single falcon heavy launch could probably handle
| that.
|
| Said another way, such a mission could probably be
| completed with one or two falcon heavy launches. That's
| basically equivalent to 3-6 falcon 9's worth of fuel, and a
| falcon 9's fuel cost is something like $200k. So,
| $600k-$1200k in fuel.
|
| A spaceship system actually suitable for going to Mars
| would probably use cheaper fuel than falcon heavy. By the
| time it's actually built, though, inflation and politics
| will have made the fuel expensive again. So my best guess
| is a cool $1million!
| jldugger wrote:
| .... Did you factor in the fuel you need to actually
| stop? I'd prefer not to be the next martian crater.
| JohnJamesRambo wrote:
| I've been watching a lot of documentaries about Mars and the
| more I learn the more it seems so incredibly daunting and
| overwhelming. The atmosphere isn't even thick enough to slow
| down properly from the massive speed you need to get there at
| a time scale that works. How do you land large colonization
| facilities, landers, etc. in an atmosphere that is 1% as
| dense as Earth's? How do you then have enough fuel to leave?
| I know there are workarounds for everything but there are
| some hard physics walls here.
|
| >The highest atmospheric density on Mars is equal to the
| density found 35 km above the Earth's surface.
| edgyquant wrote:
| I don't think colonization of Mars is the future
| regardless, but landing on Mars isn't more difficult than
| landing on the moon.
| posix_me_less wrote:
| You have been mislead, we don't need atmosphere to slow
| down. We have rocket thrust for that.
| grey-area wrote:
| _How do you land large colonization facilities, landers,
| etc. in an atmosphere that is 1% as dense as Earth 's?_
|
| With supersonic retro propulsion on a rocket that can be
| reused.
|
| _How do you then have enough fuel to leave?_
|
| You don't, so you need to make the fuel with robots landed
| on one-way missions first. Luckily there are plenty of raw
| materials on Mars (in the atmosphere, soil and water
| deposits).
|
| It's very hard but it's certainly doable if you can do the
| first part.
| rtkwe wrote:
| There has to be some revenue stream beyond just satellite
| launches and government research. Right now there's only so
| many reasons to go to space and a lot of those are pretty
| small markets or able to be served by one or very few
| provider(s) pretty well.
| NortySpock wrote:
| low attenuation fiber optic cables?
|
| https://madeinspace.us/capabilities-and-technology/fiber-
| opt...
|
| (similar to, but not the same as, zero attenuation fiber
| optic from the fictional book Artemis by Andy Weir)
| https://en.wikipedia.org/wiki/Artemis_(novel)
| posix_me_less wrote:
| Is the new book any good? I liked Martian.
| NortySpock wrote:
| I thought Artemis was decent.
|
| It ain't The Martian, but if you like the hard sci-fi of
| The Martian, Artemis is more of that (except with a
| touristy moon base).
| BenjiWiebe wrote:
| I enjoyed it, but I wouldn't compare it to The Martian.
| rtkwe wrote:
| Maybe, but you'll need more than just one thing to really
| take off. Also terrestrial fiber seems plenty fast for
| most applications at the moment?
| NortySpock wrote:
| low attenuation means fewer repeaters needed on oceanic
| cables, reducing the cost of operating the fiber optic
| cable.
|
| "Using estimates for the theoretical loss limit of ZBLAN
| glass, a 2,000-km length of ZBLAN fiber could have the
| same optical loss as 10 km of silica fiber, which would
| be an extraordinary performance gain."
|
| https://upward.issnationallab.org/the-race-to-
| manufacture-zb...
|
| "Fluoride fibers inherently provide naturally a much
| wider bandwidth than silica with up to 100x usable number
| of data channels, <2 petabytes per second of data with no
| amplification for 1,000km or more and no need to carry
| power for said amplification lines. By comparison,
| current undersea cables use one repeater for
| amplification every 100-150km, at a cost of ~$1M each."
|
| https://www.spiedigitallibrary.org/conference-
| proceedings-of...
| ChuckMcM wrote:
| Frankly, I expect the zero-g sex market to be a pretty big
| draw for the folks with more money than sense.
| pixl97 wrote:
| I can only guess that it would be much harder to
| accomplish than one would imagine. Definitely want a
| padded room so you dont bang your head, or other parts
| slamming into sharp objects.
| ChuckMcM wrote:
| I note that the Bigelow Aerospace semi-inflatable
| module[1] that is attached currently to the ISS has no
| windows and padded walls.
|
| [1] https://bigelowaerospace.com/pages/b330/
| GordonS wrote:
| Putting aside space-sex, I really like the idea of an
| inflatable module that can quickly (and _presumably_
| fairly cheaply) increase the space on a station.
| lmm wrote:
| A few people will do it once or twice, sure. Doubt that's
| a sustainable market unless you can get the cost way
| down.
| edgyquant wrote:
| Zero-g sex is extremely dangerous. There was an episode
| of the Universe about it.
| godelski wrote:
| Sorry, what? The reason we have so many launch providers
| today is because space is extremely valuable. Even though
| you don't realize it there are hundreds of satellites above
| you head and you're connected to many of them.
| Telecommunicate (not just your phone), GPS, weather, etc.
| We wouldn't have the modern world without access to space.
| Things getting cheaper is causing a boom.
| rtkwe wrote:
| I'm largely talking about setting up a space industry
| that includes human spaceflight independent of government
| spending which is what you need for it to really take off
| because unless it's specifically designed to be
| impossible to kill like the SLS other missions get killed
| and messed with as each new admin or congress decides
| it's an easy place to make a mark.
|
| There's a lot up there but it's still not that big and
| there's limited space for new arrivals. SpaceX largely
| exists because of the government contracts to launch to
| the ISS and for various NRO launches there's not enough
| public need for launches alone to sustain a rocket
| industry is what I mean. Especially for human launches,
| the only reason to have a human rated orbital capsule is
| to service the ISS.
| akeck wrote:
| I feel like we sort of did get a "Space New Deal" in the form
| of "Let's just send robots everywhere." Not great from a
| human space flight perspective, but political will is what it
| is.
| WalterBright wrote:
| It is simply too expensive for government to do it. It'll
| have to be private enterprise. (Not that private enterprise
| could pay what NASA spends either, but that it would be 10x
| cheaper for private enterprise to do it.)
| lordlic wrote:
| You think NASA, ESA, Roscosmos, etc can build the ISS but
| they can't raise it to a higher orbit? Honestly, this
| cheering for privatization of space research is getting out
| of hand.
| WalterBright wrote:
| I'm saying that the bill for NASA doing it would be 10x
| what a free market operation could do it for.
| sudosysgen wrote:
| In 2021, the cheapest and most reliable way to send a man
| to space is to use a Soyuz, for a cost of 19-22 million
| dollars per person. This is of course a communist design
| launched by a public space agency built by a majority
| public ownership factory.
|
| I think it might be time to accept that in these cases
| its pretty often not the inherent efficiency of the free
| market - which can often be less efficient than
| alternatives - but the ineptitude of the US government
| and it's agencies as far as doing things efficiently.
|
| There are US politicians and functionaries that admitted
| publicly that they made the government less efficient for
| ideological reasons to make the free market look better.
| WalterBright wrote:
| > 19-22 million dollars per person
|
| That doesn't mean it was profitable. The price could have
| been set for political reasons. Or it could have been set
| by the marginal cost of the launch, ignoring entirely the
| development cost that was written off when the USSR
| collapsed. Or it could have been enough to simply pay for
| the weight of the astronaut in a rocket that was going up
| anyway, like a hotel will sell rooms at a deep discount
| just to not lose as much money if it cannot otherwise. If
| communism produces goods and services cheaper than the
| free market, we'd be awash in Soviet goods.
|
| The US government produces goods and services at "cheap"
| prices, but the losses are made up for by the taxpayer.
|
| > which can often be less efficient than alternatives
|
| I'd like to see a case of that.
| mdiesel wrote:
| > If communism produces goods and services cheaper than
| the free market, we'd be awash in Soviet goods.
|
| Which we aren't, because they're undercut by Chinese
| goods...
| Andrew_nenakhov wrote:
| No. Communism and planned economy are not capable of
| producing consumer goods. Source: I actually lived in the
| USSR.
| edgyquant wrote:
| Anecdotal evidence isn't evidence. They're capable, what
| they lack(ed) is the creativity to do so.
| Andrew_nenakhov wrote:
| You mean my whole youth lived around Soviet-made goods is
| an 'anecdotal evidence'?
|
| Well, perhaps I should have tried living in those fantasy
| Soviet Unions some people on the internet love so much.
| Those must have been magnificent states!
| sudosysgen wrote:
| Well, it does remain anecdotal evidence. The point of the
| above commenter is that while they could be made the lack
| of creativity in planned economies lead to them not being
| made, not that there were made.
| Andrew_nenakhov wrote:
| You talk about planned economy shows that you learned
| about it from third-party sources. There was an abundance
| of creativity, it just wasn't aimed at creating consumer
| goods, because they just could not be made in the planned
| economy _at all_.
| sudosysgen wrote:
| That might very well be true, I'm just trying to iron-man
| their argument. Do you have some sources about that and
| why that is?
| edgyquant wrote:
| Yes what you present is anecdotal evidence. Also nobody
| is saying they like the Soviet Union that is an idiotic
| strawman. My point is that they could be made but the
| USSR wasn't gearing its economy towards consumer goods
| because it was a military state who cared almost entirely
| about heavy industry to benefit its military industrial
| complex and competition with the US.
| WalterBright wrote:
| The US free economy produced a better military _and_
| plenty of high quality consumer goods.
| lordlic wrote:
| It's not too expensive for governments to do it, and it
| doesn't have to be private enterprise. Neither of those
| things are true. Nor is it even clear that it would be
| cheaper to contract with some private provider to boost
| the ISS than for the space agencies to figure it out
| themselves with the launch vehicles they have. How do you
| think NASA, ESA, etc build rockets anyway? They contract
| with Lockheed, Boeing, Airbus, Northrop, and others to
| build them. Having the whole operation be under the
| auspices of SpaceX doesn't do much other than make other
| governments more reluctant to help fund it.
| WalterBright wrote:
| Government contracting is not at all indicative of how
| the free market works.
|
| Also, the free market would never have built a design
| like the space shuttle. Pushing very heavy wings and
| landing gear into space doesn't make sense and never did.
| NewLogic wrote:
| It was actually the side-mount design that made the least
| sense. It left the heatshield completely exposed to ice
| and insulation strikes.
| WalterBright wrote:
| To be fair, the magnitude of that risk was not realized
| in the design phase. Though one could hardly miss the
| giant, heavy wings & landing gear and the heavy structure
| to support it. That was obvious to me at the time, and I
| often wondered why no article about the shuttle ever
| mentioned it.
|
| Musk figured out a far better way to make a reusable
| rocket. All it needs is a bit of extra fuel that is
| burned at the last second.
|
| (Playing the Lunar Lander game in college, I soon
| realized that the minimum fuel burn to land it was to
| fall ballistically and go to full power as late as
| possible, hitting 0 fps just as one touched down.)
| blackrock wrote:
| Could they have mounted 2 space shuttles, bottom to
| bottom, instead?
|
| Where the 2nd space shuttle was the fuel tank, and it
| lands somewhere down range, and is then transported back
| to the launch center by barge.
| krallja wrote:
| Yes, a crewed fuel tank was one of the designs
| considered, as was three shuttles (2 crewed tanks + 1
| ship) in a triangle. Visit the Udvar-Hazy Air & Space
| Museum Annex in Virginia if you ever get a chance,
| there's an exhibit on all the proposed designs. We got
| the worst possible one.
| WalterBright wrote:
| Another set of heavy wings and landing gear to push up.
| ska wrote:
| > but how do we multiply & speed up that effort?
|
| I think it's pretty much politically impossible. The first
| big space push was mostly a political pissing match (i.e. not
| really driven by doing it for its own sake). It's pretty easy
| to come up with other major challenges that most people will
| consider more important that also aren't getting funding ...
| so private industry looks more likely to get some traction.
| States might get interested if/when those efforts start to
| get more interesting or threatening.
|
| Mars in your lifetime is implausible, but not impossible I
| suppose.
| NortySpock wrote:
| China's public plans include a semi-permanent base on the
| Moon. That oughta ruffle some feathers in Congress.
|
| Chinese paper on plant-based life support systems for
| extended crew stays.
| https://www.biorxiv.org/content/10.1101/2021.01.12.426282v1
| Something1234 wrote:
| Did the Chinese build their own biosphere 2 (Arizona)?
| andi999 wrote:
| Since you mentioned biosphere 2, I was really surprised
| to learn the Steve Bannon was director for 2 years of the
| project.
| lenkite wrote:
| Really hope China ditches the Outer Space Treaty and
| claims sovereign territory on the moon. Only then will
| the space race ignite again. It seems only competition
| makes the human spirit move.
| hutzlibu wrote:
| I suspect any player powerful enough to have the means to
| claim territory on the moon, will ditch the outer space
| treaty eventually. Unless it is a purely scientific
| mission, but that is un likely at the moment.
| newsclues wrote:
| Like the last space race you just need the military to fund
| the research under the guise of civilian space exploration.
| peteretep wrote:
| > The first big space push was mostly a political pissing
| match
|
| And then next one will be too, only with China
| bnralt wrote:
| > The first big space push was mostly a political pissing
| match (i.e. not really driven by doing it for its own
| sake).
|
| My understanding is that the Defense Department was
| interested in human manned spy satellites liked the planned
| Manned Orbital Laboratory early on, but that automation
| progressed to the point where it was preferable.
|
| I think that's one thing people miss when they talk about
| lack of progress in space. We use space, a lot. The thing
| is, in terms of things we actually want to do, automated
| vessels work a lot better than manned ones. People who are
| focused on manned space missions aren't focused on space,
| they're advocates for one particular tech stack that's
| extremely inefficient at doing the things we currently want
| to do in space.
| wahern wrote:
| 10 years ago the consensus--scientists, engineers, etc--
| was that self-driving cars would be ubiquitous or on the
| cusp of ubiquity today. That same common but woefully
| mistaken wisdom is also behind the preference for remote
| space exploration and exploitation.
|
| We clearly have issues with underestimating the
| complexity of these engineering problems and
| overestimating the pace of technological progress. I'd
| also argue, albeit more contentiously, that we
| systematically underestimate the utility of a physical
| human presence at exploration sites, and the cognitive
| dissonance of our biases cause us to scale back our
| ambitions so we don't have to admit to the limitations of
| the remote-controlled approach.
|
| Exclusively committing to remote-controlled exploration
| also avoids the thorny issues around deliberately putting
| explorers into harms way or even actual harm. I think
| Musk understands, knowingly or at least intuitively, that
| the debate is basically impossible to have; our culture
| isn't equipped for it. Necessity will drive us toward
| human space exploration. Safety will be to some extent
| needlessly neglected, and then there'll be vigorous
| finger pointing and "I told you so"s after the fact--
| after the sacrifices have been made and after the
| benefits have been secured for all. Basically the same
| pattern will play out as with any other area where
| prohibition or abstention is the official choice despite
| its patent unviability.
| 7952 wrote:
| Engineering difficulty is often put forward as a limiting
| factor. But actually I think history suggests that with
| enough resources we can accomplish things. And in fact it
| is possible for a project to have astonishingly brilliant
| engineering and still be disappointing in terms of wider
| impact (see the space shuttle).
|
| The limiting factor is much more mundane. Getting humans
| to collaborate selflessly on complex projects is
| difficult. Effective communication in large groups is a
| massive unsolved problem. That is what holds us back, not
| engineering complexity. Perhaps the true genius of SpaceX
| is using Mars to bring people together. Something the
| bean counters at Boeing never thought of!
| godelski wrote:
| There's still a lot of defense reasons to go to the moon.
| You can put much larger telescopes there, though you're
| back to windows of time you can look at a location but
| you can have good will and dedicate time to scientists.
| Though they might not want to reveal the resolution even
| though this can be roughly back tracked through size.
| There's also the weapons incentive even though that's
| illegal. But if you're able to cheaply and consistently
| put people on the moon then you clearly have the
| resources to cheaply put large rods of tungsten in orbit
| (good luck responding to), being able to take out enemy
| satellites (nav, surveillance, missile launch detection,
| etc), replace/upgrade satellites quickly, etc. The Apollo
| missions were always about how much payload you could put
| in orbit.
|
| It's also beneficial if you want to start space mining,
| really essential for that actually.
| Dylan16807 wrote:
| > the resources to cheaply put large rods of tungsten in
| orbit
|
| And then it takes a big rocket to get them back _out_ of
| orbit. Such a waste of effort.
| simonh wrote:
| There have been studies and the rods from the gods
| concept doesn't work. Atmospheric braking would slow them
| to their terminal velocity before impact. You might as
| well throw them out of a plane. There are also all kinds
| of problems with time to target, terminal guidance and
| cross range capability.
| Blikkentrekker wrote:
| All of what you said can better be done by machines and
| many such things are done by machines.
|
| The milestones that get people existed are when men reach
| places hitherto unreached, but there is no practical
| purpose to risking the life of a man who needs far more
| complicated facilities to survive, other than bragging
| rights.
|
| The _I.S.S._ was largely a political and not a scientific
| endeavor, and it 's a shame it consumed so many
| resources, that could have gone to more serious
| scientific efforts.
|
| The cost of the _I.S.S._ could have easily given mankind
| nuclear fusion, -- the ability to power entire countries
| with a couple of litres of seawater. It 's strange where
| priorities lie.
| seabrookmx wrote:
| > could have easily given mankind nuclear fusion
|
| There's no proof of this because viable nuclear fusion
| has not yet been achieved. Humanity may never achieve
| this for all we know (though I sincerely hope we do).
| Blikkentrekker wrote:
| The same can be said about any research whereto resources
| are allocated.
|
| Making a reasonable estimate when both started, nuclear
| fusion seems to be a smarter investment, for if it
| finally be there, the benefits are incalculable.
| fuoqi wrote:
| >being able to take out enemy satellites (nav,
| surveillance, missile launch detection, etc)
|
| You can easily do it without having objects in orbit. You
| can simply launch a ballistic cloud of debris at
| suborbital speeds and kinetic energy of the targeted
| satellite will do the rest. Time to hit could be shorter
| for an orbital system, but not significantly so. This is
| why I consider the recent news about the Russian orbital
| satellite killer to be a cheap fearmongering.
| saberdancer wrote:
| Putting a spy telescope on Moon seems like a bad idea.
|
| - Moon moves across the sky very slowly (relative to
| stars) which means that your spy satellite would have
| about 30 days to cover full earth, and would be able to
| see only a part of Earth at any given moment
| (theoretically half, but lot of it would be from very bad
| angles) - Moon is in an ecliptic? orbit, so spying on
| anything close to the poles will be from an angle - this
| might not be bad in all cases but the lack of flexibility
| is a big thing - Putting any mass on the Moon requires
| much more delta V than putting something in orbit. If you
| can put a big telescope on Moon, you can put several in
| Earth orbit or put one much bigger one.
|
| Having capability to stage on the Moon would be
| interesting, especially if fuel can be made on the moon.
| It would be easier on human bodies and you have access to
| lot of resources. If you can find water and decent
| metals, that's a pretty good spot to fuel your rockets.
| exDM69 wrote:
| The moon moves slowly but the Earth rotates quickly. Most
| of the earth surface can be seen during one day. The
| earth is not illuminated by sunlight all the time, about
| half of the lunar month would be completely dark.
|
| Moon is in an inclined orbit, which is slightly elliptic.
| I assume this is what you meant by "ecliptic" (which
| refers to the orbital plane of the Earth around the Sun).
| The orbital inclination has the most significant
| implications to Earth surface visibility, but the Moon is
| far enough that almost half of Earth surface is visible
| at all times.
|
| For Earth observation, satellites are better positioned
| than a lunar surface observatory.
|
| The moon isn't a great place for an outpost or staging
| point for exploration. Launches and descents are
| expensive and spoil all the savings. Maybe if LH2/LOX
| could be manufactured on the moon very cheaply (from
| water ice), it could make sense to do refueling for
| exploration vehicles parked on a halo orbit near Lagrange
| points.
|
| But orbital refueling of cryogenic propellants
| (especially hydrogen) or manufacturing them on the moon
| aren't viable in the near future.
|
| There aren't a lot of good economic or exploration
| incentives to go to the moon, unfortunately. It only has
| scientific and prestige value. The long lunar night (14
| earth days) makes it a poor location for a permanent
| outpost.
|
| All of that said, I'm all for going to the moon with
| humans on board.
| saberdancer wrote:
| You are right about Earth rotating. I spaced out on that
| one.
|
| About the ecliptic, I was trying to say that any
| observatory on the moon would have issues observing polar
| regions because the Earth surface in polar regions would
| be at a low angle. I know some spy sats "look ahead" to
| get better detail resolution but they have ability to
| look from different angles as well. Moon would be a bad
| spot for that.
|
| Rest of it I mostly agree. One thing up to debate is
| whether an outpost on the moon would be useful. If you
| can manufacture fuel on the Moon, it would be very
| useful. Another aspect is human health in zero G. Moon
| with low gravity may be enough to help with long term
| human stay.
| exDM69 wrote:
| The lunar orbit is inclined so that the moon moves
| between about +/- 28 degrees north/south latitude with
| reference to the Earth equatorial plane.
|
| That's Earth's axial tilt of ~23 deg + the inclination of
| the lunar orbit w.r.t. the ecliptic of ~5 deg.
|
| This means that when the moon is at its northest (above
| southern Florida), it has a pretty good view over the
| north pole (but it's at quite an oblique angle of ~60
| deg), and the south pole is not visible. About 14 days
| later it's the opposite.
|
| But yeah, I agree with the conclusion that the Moon is
| not a good place for a Earth observation for a lot of
| reasons.
| OJFord wrote:
| > Mars in your lifetime is implausible,
|
| Do you say that to mean 'anyone living's lifetime', or on
| the assumption that GP was alive for the 'moon landing 51.5
| years ago' mentioned?
| blackrock wrote:
| But Elon says they'll land on Mars in 2026. Say it ain't
| so.
| snomad wrote:
| Seems we have dialed back manned missions, but the rovers on
| Mars, the satellites orbiting Jupiter (Juno) and Cassini,
| reaching Pluto (New Horizons), and asteroids (Hayabusa) and
| soon to be James Webb Telescope are all very exciting and
| represent significant progress.
| mlindner wrote:
| > I think we need a "Space New Deal", I'm honestly saddened
| by the lack of progress in space in my lifetime.
|
| Space is making progress at incredible rates right now. It's
| moving faster than it ever has in history. So I'm not sure
| what the issue is.
| d_silin wrote:
| Well, if you want something done, the best way is to do it
| yourself. How much labour/$$$ are you willing to put per
| month for the space exploration efforts?
| mynameisash wrote:
| > I'm honestly saddened by the lack of progress in space in
| my lifetime
|
| I just told my youngest kid this the other day:
|
| When I was his age (~25 yrs ago), my dad told me with a bit
| of a sad look on his face, "I hope we return to the moon
| within your lifetime." At the time, I kind of laughed
| because, hey, we're sending people to the moon CONSTANTLY. It
| took me a minute to realize that I was sorely mistaken and
| that we haven't sent a human to the moon at ALL in my
| lifetime. I was taken aback.
|
| All this history about Neil Armstrong and the Apollo missions
| and the space shuttles -- we even got to see from Cocoa Beach
| a shuttle launch on a family vacation. So much of it even
| from MY DAD's youth, him telling us about when he got to hear
| the famous "One small step for [a] man" live from his Scout
| Jamboree trip. All of that, and we haven't actually been to
| the moon in decades? It totally blew my mind.
|
| I think before that moment, I must have assumed that it was
| Real Soon Now before we'd have a permanent base with people
| living and even being born. And to learn that we sort of gave
| up...
|
| It's not unlike when I was six and remembered reading about
| fully autonomous cars that were coming Real Soon Now, too.
| Thirty+ years later and that reality actually seems farther
| away than I had imagined despite the actual progress we've
| made.
| ghostpepper wrote:
| What does "new deal" mean in this context? Large amount of
| public funding?
| monkeywork wrote:
| "New Deal" generally implies making it a federal priority
| and putting proper funding and focus on it.
|
| See: FDR New Deal / The Green New Deal
| mjevans wrote:
| As the sibling already mentioned, FDR's
| https://en.wikipedia.org/wiki/New_Deal
|
| It's also the framework I think of when I use my own phrase
| 'New New Deal', as in a jobs program that focuses on
| building fresh public infrastructure (not-broken window
| jobs).
| unixhero wrote:
| I loooove Lagrange points
| gizmo686 wrote:
| Is there any reason to park in at a Lagrange point instead of
| just a high orbit?
|
| There aren't that many Lagrange points, so we should probably
| avoid cluttering them with objects that don't need to be there.
| rossmohax wrote:
| from what I've read Lagrange point isn't exactly a point, but
| a region where it's cheap (in terms of fuel) to stay. They
| are quite large.
| sandworm101 wrote:
| You can orbit the lagrange point, vertically as seen from
| earth. In such orbits it functions as if it were a point
| source of gravity.
| elihu wrote:
| At some point, if you go too high you end up in the Van Allen
| belts, which if I understand correctly are a really harsh
| place for spacecraft to be. Generally those orbits are used
| for parking bulky rubbish that's too much trouble to de-
| orbit.
|
| Geosynchronous orbits are above the worst parts of the
| radiation belts, so maybe that's a good place for the ISS. Or
| even higher; it doesn't need to be geosynchronous. The main
| advantage of a low orbit is that it's easier to get to from
| Earth, but if you're just parking it long-term as a museum
| piece that doesn't matter as much.
|
| I wouldn't expect Lagrange points to have much of a problem
| with clutter unless we decide to start parking enormous
| quantities of stuff there. Objects can spread out and orbit
| the points; as long as they're all going in about the same
| direction they should be able to avoid running into each
| other.
| m4rtink wrote:
| At least for the Moon, the lunar orbit is generally unstable:
| https://en.m.wikipedia.org/wiki/Lunar_orbit
| gizmo686 wrote:
| You don't need a stable orbit, just one that will keep it
| in our neighborhood and away from the atmosphere and
| congested orbits.
|
| Put it in a high orbit, and point a telescope at it every
| now and then to update our record of it's orbit. By the
| time we are ready to visit it, even if its orbit changed,
| its new orbit would not be any more inconvenient then where
| we left it.
| namibj wrote:
| The moon's lumpy gravity field actually causes the
| eccentricity of most orbits to raise quite fast,
| eventually bringing the periapsis below the surface (or
| the apoapsis on an escape trajectory, but I recall the
| former being more of an issue):
| https://www.youtube.com/watch?v=EadClM4Y45A
| ChuckMcM wrote:
| Station keeping. The L4 and L5 points are nominally self
| stable, if you put something there it won't wander off. (this
| isn't true of the L1 point which is more dynamic). To do
| station keeping you need reaction mass and working thrusters.
| That level of infrastructure requires some maintenance,
| whereas you could put an empty/abandoned ISS in the L4 or L5
| point and it would just sit there for no additional cost.
| gizmo686 wrote:
| Right, but why do you need to do station keeping at all.
| Tracking objects is cheap, and a normal graveyard orbit
| isn't going to be perturbed so much that it would be
| notably harder to reach again in any reasonable timeframe.
| ChuckMcM wrote:
| Few chances to have a collision with existing space junk
| in either L4 or L5.
| aetherson wrote:
| That's shooting an ant with a rocket launcher. You could
| avoid space junk in much lower orbits than the Lagrange
| points.
|
| I encourage everyone to get a sense for the sheer scale
| of this. Do it on your floor or walls. Try a scale of 1cm
| = 5000km or 1cm = 10,000km. Cut out little Earths and
| moons and map out geosynch, the lagrange points, etc.
| interestica wrote:
| Orbits decay. Things change. Political priorities change.
| I mean, they didn't _want_ skylab to come down when
| /where it did.
| Faark wrote:
| Skylab was in LEO. There is hardly any decay once you get
| higher up, you're quickly approach "many lifetimes".
| That's why the new huge LEO constellations won't be a big
| space garbage problem.
| joshxyz wrote:
| Exciting times.
|
| The first wonder of the space: The ISS.
| akiselev wrote:
| _> That it is the Russian Zvevda module that is leaking
| /cracking is likely related to the fact that it is also the
| oldest module in the ISS._
|
| Definitely sounds like it. They can't identify the leak on the
| inside so it doesn't sound like a micrometeoroid impact and
| they suspect a second leak that is so small they need a
| microscope to verify:
|
| _> "So far, we have found one place and suspect another, where
| as some kind of leak exists. We must bring a powerful
| microscope on a cargo spacecraft and use to examine this place.
| We are not totally certain so far," Solovyov said._
|
| IANAMS but that screams microfractures. The Zvezda is made
| largely of an aluminum magnesium alloy [1] that has a fatigue
| limit so even small repetitive stress can cause it to
| eventually fail. I'm curious whether this is wear and tear from
| just being in space and getting irradiated or if its repetitive
| mechanical stresses like a small tidal force as it orbits the
| earth.
|
| [1] https://weebau.com/iss/zvezda.htm
| bartread wrote:
| Is it possible it could also be from constant heating and
| cooling cycles as it orbits?
| HPsquared wrote:
| Those are the cause of the stress cycles. Components don't
| expand/contact uniformly, resulting in deformation and
| therefore stress. This process goes through cycles, causing
| stress cycles which eventually cause the growth of cracks
| (fatigue).
| HenryKissinger wrote:
| Have we invented a material that is resistant to these
| thermal cycles indefinitely, or at least within a range
| of temperatures of several thousand degrees? I'm never
| going to have my own Star Destroyer if we continue to use
| subpar materials.
| normaljoe wrote:
| As the other posts point out it's not just a matter of
| material, but a trade off. As you increase the ductile
| strength you end up with something that is more brittle
| and the same is true in reverse.
|
| Brittle materials are more temperature sensitive and can
| rapidly fail. Brittle fracture is no joke look for WWII
| Liberty ships split in two as an example. We didn't
| really understand why at that point in time.
|
| The answer though is actually pretty simple and why you
| can't get a perfect material. The lattice structure of
| the molecules connected to each other can be soft
| (plastic) or hard (steel).
|
| In the plastic example just take a milk jug and poor
| boiling water into it. Don't actually do this without
| protective gear (oven mit should be fine). The molecules
| holding everything together get excited from the energy
| (heat) move around and since they are not closely bonded
| end up in a different configuration. Your milk jug at
| this point does not look the same and is deformed.
|
| In the hard example just boil the water you are using for
| the plastic test. The pot you used does not change
| because the molecules are tightly bonded.
|
| It turns out the the tighter the molecules are bonded
| there is still a point where that bond will break. Hence
| the brittle fracture, which is every molecule mic
| dropping and going home at the same time.
|
| While I could go down another rabbit hole to the atomic,
| subatomic, level of how those lattice structures work. I
| won't as I think this example gives you what you need.
|
| Finally in this case we have a very old, by modern space
| technology, structure that is made of material that was
| most likely never expected to last this long. If you want
| a space ship to last you just have to make sure the
| engineers understand what "last" means. :)
| coryrc wrote:
| Steel, below a certain loading (err, ~20% of max
| fatigue?) does have indefinite life.
| bregma wrote:
| Even burning jet fuel can't melt such steel beams?
| chaboud wrote:
| Climbers and riggers should all be familiar with fatigue
| limits.
|
| It can be as high as 50% max tensile strength for steel,
| but I use 30% as my working figure when rigging, and I
| regularly re-inspect and age-retire gear (at least use
| annualized color coded markings).
|
| When I've rigged circus in the past I've taken to
| replacing aluminum gear I find with steel, especially if
| it's going to be installed for a while.
|
| That said, I climb on aluminum. I just age out my
| equipment. I'd hate for my last thought to be "huh... I
| guess aluminum really does degrade with repeated stress."
| lanstin wrote:
| I had an aluminum bicycle where the front fork failed
| suddenly. Not instantly but in maybe one or two seconds
| (just slowly enough to let me not have a terrible fall).
| My next bike was chrome/steel.
| HPsquared wrote:
| This solves something I'd wondered for a while - why my
| aluminium bike has a steel fork.
| robryk wrote:
| I was told once that the reason for that was stiffness:
| apparently aluminum forks are stiffer, so unsuspended
| ones are way less comfortable (in terms of vibrations
| being transmitted to the frame and handlebars) than steel
| unsuspended forks.
| chaboud wrote:
| Years ago I totaled a mountain bike in a strange pinched-
| wheel-in-crack accident that bent the frame in two places
| but left me uninjured.
|
| When I commented to a bike designer/engineer that it was
| a strange failure, he said that it was intentional, at
| least on hardtail mountain bikes like mine. A bent frame
| is ruined but doesn't lead to a catastrophic loss of
| control. A detached wheel or twisted fork would be next
| to impossible to control to a stop.
|
| He looked at my frame and explained that that the two
| bends were in exactly the place they'd been designed to
| be, just behind the last butting. It's an impressive bit
| of forethought.
|
| My guess on road bikes with steel forks, though, is that
| it's a matter of aerodynamic performance calling for
| compactness to reduce frontal area, something that would
| be harder to do in aluminum, and for far less weight
| savings than the longer tubes on the frame.
|
| There's always titanium... The only big drawback is the
| cost...
| nine_k wrote:
| I would suggest a thin, non-load-bearing, and easy to
| replace insulation / reflection layer above the
| pressurized hull. It could reflect much of solar energy
| back to space, and much of the hull's radiation back to
| the hull, keeping the difference of temperatures on the
| hull much lower.
|
| I wonder if it's already implemented.
| namibj wrote:
| Carbon-Carbon composite has a cycle life in the millions
| when cyclically loaded between 0% and 85% of ultimate
| tensile strength. Furthermore, that material has a very
| low thermal expansion coefficient and remains
| structurally sound at high temperatures.
|
| It does oxidize at high temperature, so you'll have to
| coat it with something. It's also fairly brittle,
| basically a strong ceramic (it caused us to loose
| Columbia during re-entry).
| mycall wrote:
| What is the difference between "Carbon" and "Carbon-
| Carbon"? It seems incongruous.
| ygra wrote:
| I think this is this: https://en.wikipedia.org/wiki/Reinf
| orced_carbon%E2%80%93carb...
|
| which is carbon-fiber in graphite, apparently, so the
| name is apt in that it's a composite of two different
| forms of carbon with different properties.
| HPsquared wrote:
| There's plain old "carbon fiber" which is short for
| carbon fiber reinforced polymer/plastic (CFRP). This is
| the much more common type, and is a polymer matrix
| reinforced by carbon fibers. This is very strong and
| light, but not terribly heat-resistant. In a carbon-
| carbon composite, on the other hand, the plastic
| component is also replaced by graphite. This gives a very
| strong and heat-resistant, though somewhat more brittle,
| material.
| wahern wrote:
| https://en.wikipedia.org/wiki/Fatigue_limit
| blackrock wrote:
| But won't anybody think of the souls of millions of
| people, snuffed from existence, and vaporized from the
| heat of a death laser from your Star Destroyer.
|
| As if millions of voices suddenly cried out in terror and
| were suddenly silenced.
| [deleted]
| WalterBright wrote:
| If the leaks are that small, sounds like putting an elastic
| coating on it should fix it.
| dhosek wrote:
| A bit of duct tape will do the trick.
| [deleted]
| taneq wrote:
| A can of this should do it:
| https://www.holtsauto.com/holts/products/tyreweld/
| WalterBright wrote:
| Or maybe that sealant Flex Seal they advertise on TV that
| you can make a boat from :-)
| driverdan wrote:
| You joke but it doesn't take much to seal this type of
| leak. They could probably use scotch tape.
| geocrasher wrote:
| Can you imagine the infomercial mileage they'd get out of
| that?
| WalterBright wrote:
| Full Disclosure: I have no financial interest in flex-
| seal.
|
| My general experience with glues is I'll use bolts. I
| can't get superglue to stick anything together other than
| my fingers. My rear view mirror fell off again, the third
| time I glued it on with superglue.
| sverhagen wrote:
| I now imagine how you went with bolts then, having
| drilled holes through the roof of your car!
| a9h74j wrote:
| I hate glue for almost everything, but as proof-of-
| principle check out VHB acrylic adhesive tape[1], or
| Gorilla double-sided[2]. VHB adhesive is also available
| on mushroom-head dual-lock fastener, in rolls.[3] (Also
| no financial interest.)
|
| [1] https://www.3m.com/3M/en_US/vhb-tapes-us/ [2]
| https://www.gorillatough.com/product/gorilla-double-
| sided-ta... [3] https://www.itapestore.com/3M-DualLock
| ethbr0 wrote:
| Side note: there also exist more temperature-tolerant
| duct tapes.
|
| I used some of this [0] in a last ditch effort to patch a
| small tear in a Miata canopy (rubber-coated canvas?).
| Everything else fell off. It's still happily holding,
| past 3x summers and winters.
|
| [0]
| https://www.homedepot.com/p/3M-Scotch-1-88-in-x-35-yds-
| Tough...
| pasabagi wrote:
| The trick with superglue is to make sure you have a
| really good contact between two clean surfaces. If you
| don't have that, superglue will do nothing for you and
| you're better off with something else. If you do, it's
| quite strong.
|
| The annoying thing is, glues work best when you use them
| in the exact situation (material, pressure, etc) they are
| designed for, but manufacturers are really vague about
| active ingredients or fillers, so you end up having to
| buy broad-spectrum glues that are not particularly good
| at anything.
| ethbr0 wrote:
| I've had good luck with super glue when roughing and
| recleaning the interface surfaces. That said,
| cyanoacrylate (?) does seem to have sudden fracture
| failure, e.g. cracking.
|
| When in doubt, I'm a firm believer in two part epoxy [0].
| Fiberglass impregnated when necessary. Also stores
| easier!
|
| And where water is involved (e.g. fiberglass shower
| tubs), marine epoxy like PC-11 [1]. Can attest it works
| fine as a multi-year shower patch.
|
| [0] https://www.loctiteproducts.com/en/know-how/build-
| things/epo... [1]
| https://www.pcepoxy.com/products/permanent-
| repair/pc-11-past...
| dotancohen wrote:
| Superglue is horrible for rear view mirrors, for a few
| reasons none of which I remember offhand. There exists
| special rear-view mirror glue, which is easy to use and
| is a permanent fix.
| WalterBright wrote:
| I used superglue because the special rearview mirror glue
| was pretty expensive. And the latter failed anyway, which
| is why I was looking to glue it back on.
|
| I was also suspicious of the special rearview mirror glue
| being special. For example, I have a VHS head cleaner
| tape that comes with magic head cleaner fluid, refills
| cost $$$$. One sniff told me what it was - alcohol. I use
| alcohol with it, and it works just great.
|
| I also remember years ago you could buy special vinyl
| record cleaning fluid for $$$$. It's just vinyl. I use
| liquid dish detergent, which does a superb job. Doesn't
| hurt the vinyl one bit, and all the grease, dirt, hair,
| and who-knows-what-that-is is all gone. (I buy old
| records at the thrift store because I like the easy
| listening style from the 60s and 70s.)
| jccooper wrote:
| They have put tape on suspected leak areas in Zvezda
| before.
| GordonS wrote:
| So bizarre to imagine a space station patched up with
| duct tape o_O
|
| Assuming the ISS is never going re-enter the Earth's
| atmosphere, how permanent a solution is tape? Presumably
| the fracture underneath will get worse with time.
| driverdan wrote:
| They use kapton tape but close enough.
| techdragon wrote:
| Other than the growth (in terms of length across the
| surface in question) of a crack/fracture, tape is a
| pretty valid solution as long as it can hold the
| pressure. In fact on the "inside" that's even more strait
| forward since the pressure pushes the tapes bonding
| surface interface into the opening, so depending on how
| malleable the "tape" is, it might not even need "glue" to
| do the job of sealing a hole sufficiently to hold in the
| ISS' internal atmosphere.
|
| Effectively the major issue is "larger"width/diameter
| cracks/holes create greater pressures that eventually
| exceed the ability of simple "tape" to suffice for a
| workable patch. This is all ignoring any NASA engineering
| manuals and limits, I'm talking entirely theoretical "how
| long can my duct tape keep me from suffocating" type of
| engineering, just to be clear.
|
| What needs emphasis in the long term for more permanent
| structures in space is on the poorly explored topic of
| welded joint fatigue, with respect to joints that were
| welded in low earth orbit.
|
| We have welded with several techniques in space before
| (the Soviets did it) but it basically stopped there and
| not much has gone into studies of the long term fatigue
| of the resulting welded joints. If we want permanent
| space stations we need to be able to "patch them up" in a
| way that we can rely on and at least have some idea what
| the lifespan will be. It's ok if we have to re-weld
| pressure hull segments every decade or two but not if the
| large scale structural welds on a space station hull
| assembled in space only hold for a few years before they
| start leaking.
| hef19898 wrote:
| The pressure difference is one bar, so duct tape is more
| than enough to hold that. Aging is different story all
| together, so.
| gspr wrote:
| > The pressure difference is one bar, so duct tape is
| more than enough to hold that.
|
| This is something I have to consciously remind myself of
| a lot when thinking about space technology. I have this
| reflex-like feeling that "the vacuum of space" must be a
| huge obstacle. But then one remembers that 1 atmosphere
| is the equivalent pressure of a water depth of 10 m. This
| always blows my mind. In some sense, humans do live
| naturally pretty close to one end of an absolute scale
| (pressure). Dealing with near-0 temperature is hard.
| Dealing with near-0 spatial distance is hard. Dealing
| with 0 pressure is actually not _that_ hard in the grand
| scheme of things.
| gregmac wrote:
| This reminds me of one of my favorite Futurama lines as
| their ship is going underwater:
|
| "Dear lord! That's over 150 atm of pressure!"
|
| "How many atmospheres can the ship withstand?"
|
| "We'll, it's a spaceship, so I'd say anywhere between 0
| and 1."
|
| https://youtu.be/Ewu-zHH5Qwg
| WalterBright wrote:
| Space craft are run at much less than 1 atm.
| jccooper wrote:
| The ISS and all spacecraft that dock with it run at 1
| atm. Which is nearly all currently flying spacecraft.
| (And probably Shenzhou does too, since it's basically a
| Soyuz.)
| hef19898 wrote:
| Exactly! One of my preferred scenes in The Martian is
| when he repairs his blown airlock with duct tape, a thin
| tarp and a tension belt.
| tomcam wrote:
| Hmm... my first encounter with "IANAMS" in the wild. Assume
| it means "I am not a materials scientist"? I like it.
| rcthompson wrote:
| Part of the joke is that's it's NASA.
|
| (NASA stands for Not A Standard Acronym, of course.)
| geocrasher wrote:
| Brings my mind to the ultimate acronym: PCMCIA
|
| People Can't Memorize Computer Industry Acronyms
| techdragon wrote:
| How have I gone my entire career without hearing this
| one.
| grogenaut wrote:
| TLA and FLA are my favorites
| toxik wrote:
| Three / Four Letter Acronym, respectively.
| Lvl999Noob wrote:
| What's TLA and FLA?
| atsaloli wrote:
| It's a YABA (Yet Another Bloody Acronym). :)
| fastball wrote:
| I personally prefer TLAs.
| midasuni wrote:
| And ETLAs?
| NASAtrivia wrote:
| NASA actually stands for 'Need Another Seven Astronauts.'
|
| -It's a reference to the seven people on the Columbia
| Disaster; - https://en.wikipedia.org/wiki/Space_Shuttle_C
| olumbia_disaste...
| vaduz wrote:
| It completes a cycle of heating and cooling every 90 minutes
| as it orbits. The temperature differential between
| sunlit/shaded is quite large, so even though it certainly
| does not heat to +120C / cool down to -100 C as there is just
| not enough time, it would still put some stress on it.
| rtkwe wrote:
| The hull where they're able to manually inspect it
| shouldn't be going through quite that extreme of a
| temperature differential because it's wrapped in insulation
| and protective layers. But it's also almost 21 years old so
| even the smaller actual cycle is probably getting to it
| combined with all the other mechanical stresses from
| equipment and thruster firings.
| Out_of_Characte wrote:
| I was curious so I checked what temparature the sun exposed
| parts reached and what the shadow side reaches; 121c to
| -157c a temparature difference of over 278 degrees. Your
| remark was almost spot on.
|
| https://science.nasa.gov/science-news/science-at-
| nasa/2001/a...
| joe-collins wrote:
| Or simple mechanical stress when the ISS raises its
| altitude. The thrusters cause vibration, and are not
| applying a uniform force across its surface.
| Rebelgecko wrote:
| I would imagine that there's also some temperature swings on
| the skin of the ISS
| derekp7 wrote:
| For future spacecraft, would it be possible to have a double
| hull with a self-healing jell in the middle? (In concept, I'm
| thinking similar to tire sealer, something with clotting agents
| in it).
| theodric wrote:
| That'd stop the leaks but not mitigate the risk of
| catastrophic hull failure caused by untreated cracks
| originating from repeated thermal cycling stresses
| deepsun wrote:
| Make it robotic only. Stop/dump all life support, but leave
| manipulators/robots like Canadarm, and accept robotic add-ons
| and commercial sub-satellites.
| alex_duf wrote:
| A good chunk (arguably the most important one) of the
| research is actually done on the live subjects that go up
| there.
|
| So you'd lose a lot of research capability.
| babs56 wrote:
| Where do you get this information from? I would love to read
| more about it...
| blackrock wrote:
| I think it's time to junk the ISS. It's outlived its usefulness.
| It's now in old age, and has outlived its design parameters.
|
| I think it's time to build a rotating space station.
|
| We've got all the knowledge from a microgravity space station, as
| we're going to get. The conclusion is that it sucks. Humans are
| not meant to live in space without gravity. The muscle and bone
| deterioration is too great. And the eye damage is too great.
|
| We need gravity. The question is whether we can get it from
| centripetal acceleration instead, to provide a long term
| habitation in space for humans.
| collyw wrote:
| Do they have a roll of duct tape up there with them?
| analog31 wrote:
| I hope JB Weld and Shoe Goo work in space, or our hopes of
| interstellar travel are dashed.
| rstupek wrote:
| Duct tape should fix them right up
| vaduz wrote:
| The cosmonauts (Russian segment) already tried the tape [0] -
| it helped, somewhat, but did not fix the problem. Definitely
| not as advertised...
|
| [0] https://www.spacedaily.com/reports/Air_leak_rate_at_Russi
| as_...
| edgarvaldes wrote:
| >Definitely not as advertised...
|
| American components, Russian components, all made in
| Taiwan!
| kevin_thibedeau wrote:
| Save a seat for the Flex Seal guy.
| fctorial wrote:
| ... I sawed the ISS in half.
| TeMPOraL wrote:
| You're joking but this reminds me of a hard sci-fi novel I
| read recently, Saturn Run[0]. One of the minor
| worldbuilding trivia there is that adhesives seem to be way
| overused to fix and modify things in space.
|
| (The book also features the coolest design for a radiator
| I've ever seen anywhere.)
|
| --
|
| [0] - https://www.goodreads.com/book/show/24611668-saturn-
| run
| sudosysgen wrote:
| Out of the curiosity, what is the radiator design?
| TeMPOraL wrote:
| rot13 because it's a bit of a spoiler (IMO half the fun
| of reading hard sci-fi is seeing the science and
| engineering being presented):
|
| Gur fuvc gur cebgntbavfgf geniry ba vf cebcryyrq ol
| INFVZE guehfgref, cbjrerq ol n ahpyrne ernpgbe ehaavat
| zbygra zrgny nf pbbynag. Gb enqvngr njnl tvtnjnggf bs
| gurezny cbjre, gurl rzcybl n enqvngbe gung vf rffragvnyyl
| n ynetr neenl bs 3Q cevagref. Gurer ner ornzf fbzr
| uhaqerqf bs zrgref ybat, gung pbagvahbhfyl rkgehqr gur
| yvdhvq zrgny pbbynag vagb fcnpr nf ybat naq guva evoobaf.
| Gur zrgny evoobaf pbby qbja, enqvngvat njnl raretl, naq
| ner thvqrq ryrpgebzntargvpnyyl gbjneqf n ornz shyy bs
| ebyyref, gung pncgher gur sebmra evoobaf, juvpu gura trg
| zrygrq naq chfurq guebhtu gur ernpgbe ntnva. Gur flfgrz
| erdhverf evqvphybhf nzbhagf bs npgvir pbageby, naq nf lbh
| pna vzntvar, znlurz pna unccra vs vg znyshapgvbaf.
| Freaky wrote:
| Further reading -
| uggcf://ra.jvxvcrqvn.bet/jvxv/Yvdhvq_qebcyrg_enqvngbe
| [deleted]
| pavel_lishin wrote:
| That sounds incredibly fragile, but I'm guessing most of
| the technology and infrastructure I depend on on a daily
| basis is also incredibly fragile.
| sudosysgen wrote:
| Wow. That truly is an amazingly cool radiator design
| idea. I'm going to put the book on my list!
| cuSetanta wrote:
| Scotchweld 2216 is often the glue of choice in space
| aplications, or if higher temperatures are needed there are
| other more specialist glues out there.
|
| But Scotchweld is as easy to use as JB Weld and also very
| cheap.
|
| Source: Am an spacecraft AIT engineer responsible for much
| gluing
| StillBored wrote:
| I'm betting on something closer to "slime" the stuff they put
| in tubeless mountain bikes. Or at least I don't know why the
| thing isn't built with an inner self sealant. If nothing else
| if its made with a bit of florescent die locating leaks becomes
| as simple as looking for the glowing spot on the outside.
| chippiewill wrote:
| Like painting it with frakkin' Cylon goop
| gumby wrote:
| Look like one of the panels is damaged too -- what's the story on
| that?
| calcifer wrote:
| It's a radiator panel that was damaged ~12 years ago, possibly
| due to a micrometeorite. It didn't really cause a significant
| drop in cooling capacity so they left it alone.
| mkr-hn wrote:
| Fly a football field around the planet for 20+ years and it's
| bound to intersect with something.
| dtgriscom wrote:
| I'd hate to see all that material/equipment burn up in the
| atmosphere. How much would it be worth just as an orbiting
| junkpile for scavenging by new projects?
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