Author Topic: The Absence of Airlocks  (Read 2734 times)

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #150 on: September 10, 2019, 01:01:12 PM »
With the retirement of the space shuttle...

Oh, lordy, there's a blueprint nightmare.  Paper drawings are bulky, and time-consuming to produce.  But they have the advantage of requiring only eyeballs to read them.  Computer-aided design is ostensibly a time-saver, but the progression of incompatible CAD technologies throughout the lifespan of the STS system resulted in no universal, comprehensive, correct set of design documents.  According to some engineers, the only definitive reference was literally to go out to the OPF and visually examine the orbiter in question.  The shuttle unquestionably existed and unquestionably flew.  The difficulty in amassing comprehensive design documentation for it does not undermine that.

Conspiracy theorists seem to insist on a rosy view of any prior effort.  They don't appreciate that one of the consequences of constantly working at the leading edge of technology is that we often have to say, "Yeah, if I had it to do over again I would do it differently."  A project can achieve its objectives, yet still leave behind a trail of processes and methods that turned out to be more trouble than they were worth.  The industry has to be allowed to correct its mistakes.

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I know some sort of separating crew compartment system was contemplated for the shuttle early in the design but dropped due to the extra mass involved. At any rate, if ever they come up with a new reusable shuttle, how much of the old design do you think will be incorporated into a new design?

Not nearly as much as the layman probably guesses.  First, we know the design was oversold by starry-eyed officials.  So yes, any new design would have to be safer and more cost-effective.  That means throwing out quite a lot of shortcuts that STS took.  But also, the STS design was muddied by imposed requirements in the early stages.  A lot of these were later dropped, either too late in the design process or well into the operational phase.  This left the shuttle hobbled by things such as cross-range landing capability for secret payloads, which then makes the common-case mission more problematic.
"Facts are stubborn things." --John Adams

Offline Glom

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Re: The Absence of Airlocks
« Reply #151 on: September 10, 2019, 01:46:36 PM »
What about the Saturn V wouldn't have made regulatory compliancy today?

I was specifically thinking of captures for the stage separation hardware.  You aren't allowed to fill space will little bits of material from frangible or explosive fasteners.  They have to be built in a way that the pieces are captured and contained.  At one time I had whole list, but that's what I can remember off the top of my head.
Ah yes. The Attenborough plastic crisis of space. They were quite the litterbugs on the Moon too, though that's no potentially lethal litter.

Offline Von_Smith

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Re: The Absence of Airlocks
« Reply #152 on: September 10, 2019, 03:48:42 PM »
When he doesn't get applause for his clearly superior intellect and out-of-the-box thinking, he quickly sends out another act.

I am now picturing jr Knowing hastily rushing out dancers in spacesuits to the tune of "Galop Infernal".

This thread should be renamed "The Presence of Bollocks"

Offline sts60

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Re: The Absence of Airlocks
« Reply #153 on: September 10, 2019, 04:44:51 PM »
Regarding SLS and infrastructure, SLS, and Orion, and the supporting ground segment are being built, and SLS will fly in (probably) 2021.  People are working furiously on all three segments of this human-rated super-heavy-lift capability.  SLS will fly before before Elon Musk’s gleaming next-gen idea will, and it will be by quite a bit the most powerful launch vehicle in the world.

This is just a reality check.  SLS does suffer from all the managerial and political issues mentioned, and it is guaranteed to be hideously expensive and set up for failure as an ongoing operational program.  But it’s fantasy to claim that Starship will render SLS obsolete before SLS flies, because designs and prototypes don’t trump actual  flying hardware, and SLS/Orion/KSC ground segment are much closer to reality, like it or not.  Hardware is already being produced for the 2nd SLS and Orion flights, and the VAB and Crawler and Mobile Launcher are already configured and being tested for SLS/Orion even though development is not complete.

Offline Abaddon

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Re: The Absence of Airlocks
« Reply #154 on: September 10, 2019, 05:20:50 PM »
Hi Abaddon,

The lack of blueprints is not baloney. The only thing out there, (for the most part) are dumb downed diagrams intended for media use.
Classic argument from ignorance. You can't find it therefore it does not exist. Did it never occur to you that such blueprints are not NASA's but are proprietary company information and are not on the internet anyway? Of course not. Because you simply don't think.

Furthermore, why on earth would we build a brand new spacecraft using archaic 60's technology? That would be a stupid plan.

Offline Abaddon

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Re: The Absence of Airlocks
« Reply #155 on: September 10, 2019, 05:27:52 PM »
Hi Atomic Dog

Why go out 10000 miles? Test steering in a vacuum for one. 


Earth's atmosphere extends out 10,000 miles?

Quit trolling.

Offline ineluki

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Re: The Absence of Airlocks
« Reply #156 on: September 12, 2019, 07:23:11 AM »
Here's a question for the ages, jr Knowing. If someone like you could 'figure out' an airlock would be needed, why didn't the folks at Grumman? Even if it was a hoax, these folks would still be doing their darndest to design and build a functional Lunar Module, right?

Leaving aside all science... this is something i would like for jr to adress...   





Offline Jason Thompson

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Re: The Absence of Airlocks
« Reply #157 on: September 12, 2019, 07:36:45 AM »
So, jr, since you are supposedly familiar with the problems of black body radiation and associated equations, do you still contest that a fully powered up LM sitting in the sun should have frozen a frozen interior within seconds or minutes of opening the hatch?
"There's this idea that everyone's opinion is equally valid. My arse! Bloke who was a professor of dentistry for forty years does NOT have a debate with some eejit who removes his teeth with string and a door!"  - Dara O'Briain

Offline ka9q

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Re: The Absence of Airlocks
« Reply #158 on: September 12, 2019, 09:47:39 AM »
I was specifically thinking of captures for the stage separation hardware.  You aren't allowed to fill space will little bits of material from frangible or explosive fasteners.  They have to be built in a way that the pieces are captured and contained.  At one time I had whole list, but that's what I can remember off the top of my head.
Space debris is indeed a serious problem, but I don't see a big debris problem with the Saturn V. All the stage separations occur before reaching orbit, so any debris generated during them is a non-problem. A more interesting question is what happens to S-IVB/Apollo separation debris on a lunar mission. If the TLI burn is for a free return trajectory, then (assuming small relative velocities) any separation debris (e.g., the LM adapter panels) will loop around the moon, return to earth and burn up. Other TLIs might be into trajectories that loop around the moon and escape, go into high earth orbits that aren't a problem, or maybe even impact the moon.

Even incidental debris generated during the parking orbit phase isn't likely to be a problem because those orbits were so low for performance (especially for the J missions) that any debris would have a very short orbital lifetime assuming it leaves at low relative velocity.

My big problem with the Saturn V is the enormous amount of helium it expends on every launch. There's finally a growing awareness of how limited and precious a resource that is. I would give serious consideration to alternate ways to pressurize tanks and operate valves. I believe the Saturn already did some of that (e.g., using gaseous oxygen to pressurize the LOX tanks) but I'm not sure what you'd use to pressurize an RP-1 tank. Hydrogen? Nitrogen and argon are probably too heavy.

Offline sts60

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Re: The Absence of Airlocks
« Reply #159 on: September 12, 2019, 10:24:31 AM »
Well, I can tell you SLS will still use a bunch of helium.  So nothing new there.  The conserving factor is that there may not be more than a few SLS launches the way things are going.

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #160 on: September 12, 2019, 11:51:28 AM »
Even incidental debris generated during the parking orbit phase isn't likely to be a problem because those orbits were so low for performance (especially for the J missions) that any debris would have a very short orbital lifetime assuming it leaves at low relative velocity.

Right, it's not likely to be a practical problem.  But rather than wonder about the effects of payload separation debris, the agreement is simply not to generate it at all.  I guess if we're talking about the limited case of simply reproducing Apollo missions, right down to the orbits, then we could probably get a Saturn V flight grandfathered due to the altitude.  I was thinking about the case where we might extend the Apollo mission profile, or conceivably resurrect the Saturn V as a general purpose heavy lift booster.  But then again, the overriding point was to emphasize the common argument that once we've accepted that we have to update the Saturn V design to be able to build and fly it in modern times, we have to consider whether the cost and effort to do that erodes the supposed shortcut.

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My big problem with the Saturn V is the enormous amount of helium it expends on every launch. There's finally a growing awareness of how limited and precious a resource that is.

Yeah, environment responsibility is part of the new spacescape.  When I talked about aerospace being "exotic," what I meant was that in the 1960s the excitement over space exploration outweighed the adverse effects the industry had, or was likely to have.  Toxic fuels, expensive and irreplaceable consumables, etc.  In many ways, space engineering has become a victim of its own success.  Access to space is so straightforward that the relevant industries are now regulated just as any other sector of commerce.  That filters down even to things like labor relations.  Kennedy's challenge to get to the Moon before the end of the decade might have once been enough to get people to work 18 hours a day, seven days a week, for years on end.  But today you would run afoul of UAW and just the normal expectations of how to treat labor.

The point being that going to the Moon today, using the same technology, infrastructure, and practices, would mean in many cases reverting back to various conditions and practicalities that existed at the time.  That makes it all not quite the shortcut other people claim it would be.
"Facts are stubborn things." --John Adams

Offline ka9q

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Re: The Absence of Airlocks
« Reply #161 on: September 12, 2019, 11:56:06 AM »
The point being that going to the Moon today, using the same technology, infrastructure, and practices, would mean in many cases reverting back to various conditions and practicalities that existed at the time.  That makes it all not quite the shortcut other people claim it would be.
Oh, absolutely no argument there.

The Apollo oral histories are replete with examples of marriages breaking up because of the long hours put in by many Apollo workers. People who would take great offense at claims it was all a scam.

Probably nothing captures the essence of these people than the saying "If it fails, it won't be because of me." Think about how remarkable a thing to say that was for a large government project.
« Last Edit: September 12, 2019, 11:57:45 AM by ka9q »

Offline NthBrick

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Re: The Absence of Airlocks
« Reply #162 on: September 12, 2019, 12:06:08 PM »
Here's a question for the ages, jr Knowing. If someone like you could 'figure out' an airlock would be needed, why didn't the folks at Grumman? Even if it was a hoax, these folks would still be doing their darndest to design and build a functional Lunar Module, right?

Leaving aside all science... this is something i would like for jr to adress...
I'll just slap an agreement on here, too. Engineers aren't idiots -- if you're attempting to hoax something, but need to put up a front of legitimacy, the last thing you want to do is have engineers build something that they know won't work. Otherwise, you're needlessly increasing the number of people who have to know about the conspiracy.

Offline bknight

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Re: The Absence of Airlocks
« Reply #163 on: September 12, 2019, 12:36:22 PM »
Here's a question for the ages, jr Knowing. If someone like you could 'figure out' an airlock would be needed, why didn't the folks at Grumman? Even if it was a hoax, these folks would still be doing their darndest to design and build a functional Lunar Module, right?

Leaving aside all science... this is something i would like for jr to adress...
I'll just slap an agreement on here, too. Engineers aren't idiots -- if you're attempting to hoax something, but need to put up a front of legitimacy, the last thing you want to do is have engineers build something that they know won't work. Otherwise, you're needlessly increasing the number of people who have to know about the conspiracy.

Conversely why would one design and build something that would work and not use it.  This was one of the arguments that our recent poster Derek K Willis proposed.
Truth needs no defense.  Nobody can take those footsteps I made on the surface of the moon away from me.
Eugene Cernan

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #164 on: September 12, 2019, 01:10:30 PM »
So, jr, since you are supposedly familiar with the problems of black body radiation and associated equations, do you still contest that a fully powered up LM sitting in the sun should have frozen a frozen interior within seconds or minutes of opening the hatch?

Yeah, we need to underscore this.  It's the SM RCS and fluid dynamics all over again.  To refresh memory, Jr claimed the SM RCS were in danger of damage from the slipstream of the ascending Saturn V.  I pointed out boundary layer separation, and went into some detail about why it was occurring there, and what the mitigating effects would be.  Only after I brought all that up did Jr Knowing claim competence in fluid dynamics.  But then he refused to employ that competence to show how my explanation was wrong.  Or, in the alternative, to reconcile his earlier claim with the known realities of the science.

So here we are again.  After someone valiantly goes through the effort to explain the science of radiative heat transfer in more detail and to work a problem, then -- and only then, after someone else's explanation -- does Jr Knowing regurgitate what others have explained and assure us he knows all about it.  But he refuses to apply that claimed understanding either to give a substantive rebuttal to his critics or to reconcile this newly professed knowledge with his earlier claims.  Let's be absolutely clear:  one cannot claim simultaneously a suitable knowledge of radiative heat transfer and also a factually-supported belief that the LM would have necessarily cooled rapidly to a point unsuitable for the equipment on board.  Belatedly saying, "Yes, I know all about thermal radiation" doesn't erase that the premise of the former argument was not only ignorant of thermal radiation, but following a fairly common layman's misconception of it.  Claiming per dicta that one knew it all along doesn't rebut evidence from before that one clearly didn't know it all along.

In both cases Jr Knowing adamantly insisted that our belief in his ignorance wasn't well founded.  But he declined on both cases to remedy the previous claim, or to mount a substantial rebuttal.  He wanted to make sure he portrayed himself as competent, but couldn't pony up the evidence of that newly claimed competence.  It's all face-saving, not science-making.
"Facts are stubborn things." --John Adams