Author Topic: The Absence of Airlocks  (Read 14213 times)

Offline Glom

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Re: The Absence of Airlocks
« Reply #90 on: September 09, 2019, 10:41:36 PM »
Bezos is a bookshop owner. He's not an expert on space technology. He merely uses his bookshop wealth to pay experts to develop spacecraft. And god bless him for it.

But his philosophical musings can't be taken a expert testimony on the credibility of Apollo technology.

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #91 on: September 09, 2019, 10:48:11 PM »
Just like aeronautical engineers of the 1930s and 1940s were able to make incredible advances in aviation (the Douglas DC-3, the Lockheed P-38 Lightning, the Heinkel He 178) with no computers or advanced numerical modeling.  Slide rules, scale models, wind tunnels, engine test stands, and armies of engineers can go a long way.

Any who are interested, go hunt down Catechism of the Locomotive.  It's a treatise from Victorian times on how to design and build a steam locomotive.  The degree of sophistication is surprising.  There are simple phase diagrams for laying out the valve gear and to establish the lap and lead on the valves, all rigorously mathematical in their underpinnings but rendered in geometry that is simple and intuitive.  It's correct, simple, and elegant.

Among the points Bezos makes is that we simply do things differently these days.  And it's common to believe that there were no previous methods or tools to accomplish the same goals.  There were.  The anachronism that Bezos speaks of is not that Apollo engineers did things that would only have been possible with computational finite-element methods or other advanced tools.  It's that they were motivated to go above and beyond their baseline capability with the tools they had.
"Facts are stubborn things." --John Adams

Offline jfb

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Re: The Absence of Airlocks
« Reply #92 on: September 09, 2019, 10:50:32 PM »
I realized it would help to show the work...

And well done.

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Things will get cold in space if they radiate away all their heat and there's nothing to warm them up again.

That's where the math makes you cry, because practical solutions require adjusting the single-surface computations to accommodate incoming radiation from other sources, including heat radiated from portions of a convoluted surface (belonging to the same object) that can "see" each other.  This is what the 13-element model for the LM was meant to accomplish.  The student might ask, "Do those effects matter?"  The answer in many cases is, "Yes, they do."  Portions of the LM radiated away their heat in directions that other parts of the LM could see and receive energy from.  This affects how rapidly they themselves cool by radiation, because Thot is not a simple value.

Which is why I stuck with a solid block of aluminum.  I know my limits.  I made it through DE with a D for “Done” and am thankful on a daily basis I don’t need to use anything more advanced than basic algebra. 

But when Jr or cambo start making quantitative arguments, I feel like that needs to be met head-on with actual numbers.

Offline NthBrick

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Re: The Absence of Airlocks
« Reply #93 on: September 09, 2019, 11:15:57 PM »

Any who are interested, go hunt down Catechism of the Locomotive.  It's a treatise from Victorian times on how to design and build a steam locomotive.  The degree of sophistication is surprising.  There are simple phase diagrams for laying out the valve gear and to establish the lap and lead on the valves, all rigorously mathematical in their underpinnings but rendered in geometry that is simple and intuitive.  It's correct, simple, and elegant.

Through the wonders of the World Wide Web, that was easy: http://ibls.org/mediawiki/index.php?title=Catechism_of_the_Locomotive

There is decidedly a certain joy in reading about how engineers in the past approached problems. And, for what it's worth, there's a part of me that prefers the very clear, spartan, no-nonsense style of old textbooks to that of new ones. I've had the fortune of inheriting a lot of my grandfather's old undergraduate engineering books, and they are eminently straightforward.

Offline jr Knowing

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Re: The Absence of Airlocks
« Reply #94 on: September 09, 2019, 11:18:58 PM »
Blue Origin Board of Directors Meeting

Book Shop Owner - "Well we have been in business nearly 20 years now. I am spending a billion dollars a year to finance this endeavor, where are we at? How far off earth have we got?

CEO- "60"

Bookshop owner- "60,000 miles. Wonderful."

CEO- "No 60 miles"

Bookshop owner - "60 miles? In 20 years? Wtf. NASA put six craft on the moon 240000 miles away after only 5 or 6 years of development 50 years ago. Are you saying we can't even do a quick 2 hour 10000 mile joyride into space and back?"

CEO- "Yup, Didn't you get the memo? Something about a time warp. And all the technology was destroyed.  And blueprints? Apparently they have been misplaced. Here I will let Don Petitt, US's longest serving astronaut explain it to you"



Bookshop Owner- "Ahhh... that explains it. Here's another cheque for a billion. Promise me we can get to at least 100 miles up before I run out of Amazon stock."

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #95 on: September 09, 2019, 11:22:13 PM »
Which is why I stuck with a solid block of aluminum.  I know my limits.

Or rather, the reasonable limits that apply to an academic exercise.  This is a problem we run into in engineering education, and in other fields.  "Jay, can you work problem number two from the homework?"  "No."  "Why not?"  "Because it will take about six hours to solve by hand."  We tend to stick to the toy problems for classroom exercises and trust that the concepts will scale in the face of homework and, later, real-world problems.

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But when Jr or cambo start making quantitative arguments, I feel like that needs to be met head-on with actual numbers.

Yes, that's a strong, valid rebuttal.  I don't disagree, but I feel that the burden-of-proof principle should get some air time too.  When a claimant makes quantitative assertions, I feel that they need to be backed up with quantitative rationales before there is an obligation to rebut at length.  In my younger days I provided detailed, documented rebuttals to many claimants, only to have them ignored.
"Facts are stubborn things." --John Adams

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #96 on: September 09, 2019, 11:28:08 PM »
Blue Origin Board of Directors Meeting

Sorry to interrupt your rampant fantasization, but the adults are trying to test your claims.  Nobody is buying your ludicrous attempt to twist Jeff Bezos' statements into something that argues for time travel as the only means to bring about Apollo.  Drop it.  It didn't work.

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[Pettit video]

If you had any experience in the aerospace industry, you'd be able to put Pettit's statements in their proper context.  Do you concede that there's an interpretation of his statement that that allows the technology once to have existed?  Or is this another case of you demanding -- "Textbook.  Simple." -- that you can't possibly be reading into a statement something its speaker didn't intend?
"Facts are stubborn things." --John Adams

Offline Abaddon

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Re: The Absence of Airlocks
« Reply #97 on: September 09, 2019, 11:37:38 PM »

CEO- "Yup, Didn't you get the memo? Something about a time warp. And all the technology was destroyed.  And blueprints? Apparently they have been misplaced.
You are going with the lost blueprints narrative? We already know that is baloney.

Offline jr Knowing

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Re: The Absence of Airlocks
« Reply #98 on: September 09, 2019, 11:38:04 PM »
Hi Jay,

Petitt is making a rationalization. He knows the technology doesn't exist now but because he believes or assumes the Apollo missions were real, so he is suggesting it once existed. But he also says it is a painful process to rebuild it. Why? It only took 5 years of development 50 years ago to put a man on the moon. Surely, with all of man's advances since then, it should be easier and a shorter time frame now. Do you not agree?

Offline jr Knowing

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Re: The Absence of Airlocks
« Reply #99 on: September 09, 2019, 11:43:22 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.

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #100 on: September 09, 2019, 11:58:46 PM »
But he also says it is a painful process to rebuild it. Why?

Because today there is no political will to do it, no vision for it galvanized by a dead beloved President and a politically-savvy NASA administrator, and inconsistent funding.  And also because the aerospace industry today is no longer exotic and therefore no longer exempt from regulations and practices that were either not in place or not enforced in the 1960s.  It would be illegal, for example, to fly a Saturn V today because it does not meet international standards for launch vehicle design.

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It only took 5 years of development 50 years ago to put a man on the moon.

How are you reckoning those five years?  Starting when and ending when?

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Surely, with all of man's advances since then, it should be easier and a shorter time frame now. Do you not agree?

I do not agree.  The argument in favor of your expectations is just vague handwaving.  Instead of grand gesticulations toward "all of man's advances," describe in detail what you think some of the modern advantages are and specifically how they help.
« Last Edit: September 10, 2019, 12:11:14 AM by JayUtah »
"Facts are stubborn things." --John Adams

Offline JayUtah

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Re: The Absence of Airlocks
« Reply #101 on: September 09, 2019, 11:59:29 PM »
The lack of blueprints is not baloney. The only thing out there, (for the most part) are dumb downed diagrams intended for media use.

Where have you personally looked?  How do you know what's available?
"Facts are stubborn things." --John Adams

Offline jfb

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Re: The Absence of Airlocks
« Reply #102 on: September 10, 2019, 12:01:25 AM »
CEO- "Yup, Didn't you get the memo? Something about a time warp. And all the technology was destroyed.  And blueprints? Apparently they have been misplaced. Here I will let Don Petitt, US's longest serving astronaut explain it to you"



Bookshop Owner- "Ahhh... that explains it. Here's another cheque for a billion. Promise me we can get to at least 100 miles up before I run out of Amazon stock."

Oh for God’s sake, this nonsense again.  Look, we know you’re just a dishonest troll who really needs a better hobby (I recommend guitar) but when you pretend to be this dumb it just makes it harder to play along.

You and your fellow HB weenies are deliberately misrepresenting Petit’s statement.  We didn’t lose or misplace anything.  We chose to stop building the Apollo hardware and scrapped the tooling in favor of STS.  What he’s saying is we don’t have anything we can just pull off the shelf, dust off, and fly to the Moon today.  We have to build new vehicles, new spacecraft, new infrastructure, etc.  Which we are doing - it’s just taking a lot more time and money than it reasonably should. 

Offline Obviousman

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Re: The Absence of Airlocks
« Reply #103 on: September 10, 2019, 12:12:16 AM »
According to jr's reasoning, Concorde was a hoax.

Offline jr Knowing

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Re: The Absence of Airlocks
« Reply #104 on: September 10, 2019, 12:14:22 AM »
Hi Jay and jfb,

Sorry, I should have said 7 years of development (from 1961-1968 Apollo8)

Jfb, I think you can interpret Petitt's comments as you suggest. It still doesn't change the fact (or why) after 50 years they have not used "this technology" on one vehicle, one craft, or one program in which man has left earth's orbit. Even for a quick test joyride.  And you suggest they are doing it now? They have been saying that for years. Kicking the can and changing the goalposts all the time. Trump says we are going to the moon just recently. Then someone "kicked" him and now we are instead going to Mars. That should buy another 20 years of time.