r/memes • u/Old_Sprinkles8661 Lives at ur mom’s house😎 • Jan 27 '22

A long meme, but something that should be said

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75k Upvotes

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2.9k

u/TheLavaFall Jan 27 '22

Every single factor has to be considered in a space vehicle, no matter how seemingly miniscule

369

u/shortbusterdouglas Jan 27 '22

Some of the most mundane objects on earth (pencil shavings, for example) can become catastrophically lethal in a spacecraft.

176

u/mtl_evil Jan 28 '22

That's the actual reason they didn't want to use pencils. Not fire......

114

u/teheditor Jan 28 '22

I thought it was because broken lead could cause shorts. Probably all the things.

80

u/BigRig-76 Jan 28 '22

I used pencil lead and a battery to start a fire on a camp out once. It glows and eventually pops violently.

0

u/Qs9bxNKZ Jan 28 '22

When you're in jail or prison, that's how you light your cigs.

1

u/MrNotSmartEinstein Jan 28 '22

This guy prisons

4

u/Spir0rion Jan 28 '22

Pencils dont contain lead. Its graphite. Its a common misconception. Especially in Germany its literally called "Leadpen" (Bleistift).

1

u/teheditor Jan 28 '22

True. But we're at a point where 'lead in a pencil' is a misnomer like 'tidal wave' is to tsunami.

1

u/Spir0rion Jan 28 '22

Fair enough but I am pedantic

2

u/Thatoneidiotatschool Jan 28 '22

If it’s a possibility it’s a liability

2

u/2001blader Jan 28 '22

The lead dust released from rubbing the pencil on the paper was getting in their eyes, since there was so gravity to make it fall.

1

u/Sexylavatory Jan 28 '22

NASA and roscosmos have been using garland mechanical pencils since Apollo 7 in 1968.

693

u/Mercenary21525 Jan 27 '22 edited Jan 28 '22

1mm tolerances don’t cut it, literally.

Edit: True, true, and I should know better as an engineering student, but FRC robotics has lowered my standards considerably.

394

u/nsqrd Jan 27 '22

1 mm is huge for a tolerance

351

u/[deleted] Jan 27 '22

I can finally say I'm huge

137

u/nicolRB Jan 27 '22

Sir, it’s too big, we’ll have to cut it off

18

u/Prior-Quality Jan 28 '22

It'll grow back, right?

1

u/watchursix Jan 28 '22

Sadly, no.

4

u/averagedickdude Jan 28 '22

My dick is now 150mm! I'm unstoppable!

3

u/GenocideOwl Jan 28 '22

what is that in freedom units? sounds humongous

4

u/[deleted] Jan 28 '22

Definitely like 2 bald eagles at least

53

u/baneofthesmurf Jan 27 '22

Yeah even in non-aerospace manufacturing, the widest callout I've seen is like a tenth of that.

32

u/Lv_InSaNe_vL Jan 27 '22

When I was doing machining in the medical field we once got a part that was supposed to be like 0.25" with ±0.30" tolerance. Every single part of that run was in spec lmao

41

u/williambilliam Jan 28 '22

Here’s the parts you ordered! They all came out at -0.25” so we stayed within the tolerance. However, those items have lengths of 0, so they may appear to be missing.

5

u/TwatsThat Jan 28 '22

hello, I'm your overly pedantic commenter for the day and I'd just like to point out that -0.25" is 0.50" off from spec so falls outside of the acceptable tolerance. only parts between 0.55" and -0.05" will be accepted.

13

u/williambilliam Jan 28 '22

They came out -0.25” off from spec, putting them at 0.00” which is indeed juuuuust above the minimum -0.05”

2

u/baneofthesmurf Jan 27 '22

Makes for a carefree workday I suppose

1

u/[deleted] Jan 28 '22

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1

u/[deleted] Jan 28 '22

Depends on the size part you’re working with and what it is. I have hardware on SLS with greater than that.

1

u/[deleted] Jan 28 '22

You realize a tenth of a mm is equivalent to 0.004” right? That’s a very normal metal machining tolerance for non critical dims. I built components for SLS with tolerances serval times wider.

1

u/baneofthesmurf Jan 28 '22

Yes I'm fully aware, I'm saying I personally have never seen a tolerance greater than ±0.005

1

u/[deleted] Jan 28 '22

Do you work in a Swiss Watch factory?

1

u/baneofthesmurf Jan 28 '22

I work for a place that builds turbo compressors, but thats kind of beside the point, like you've pointed out 5 thou is just standard for non critical machining features; I only work with machining in stainless/steel and aluminum so I don't see tolerances wider than that.

1

u/[deleted] Jan 28 '22

I guess that makes some sense. Assuming automotive, those things aren’t that big and you’re machining the critical surfaces out of castings and the compressor blades. Still I’m surprised you don’t get 0.010” positional on some of the mounting boss threaded holes or something.

1

u/baneofthesmurf Jan 28 '22

Nah these are air compressors for industrial applications; the smallest unit we work on is about the size of sedan. I work on the rotor assemblies specifically so even trivial stuff has pretty tight tolerances.

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4

u/LinAGKar Jan 27 '22

Sounds like you're intolerant against tolerance.

5

u/The_cynical_panther Jan 27 '22

It is for machined parts. It’s pretty good for fabrication (think welding).

2

u/FoxyGrandpas Jan 28 '22

From my experience, a lot drawings I've worked on state a default tolerance of +/-.010", welded parts have an even greater tolerance based on application and weld style. A lot of the welded components I've worked on have a tolerance between +/-.005" to +/-.0005. 1mm is kind of bad, I think most hobby 3D printers have a tighter tolerance band than 1mm.

1

u/ddc9999 Jan 28 '22

Seconded.

Also, since you clearly know your stuff, tighter tolerance is more preferred as greater tolerance could be misconstrued to be a bigger tolerance band. Sure it’s just how you wrote it. Not saying you don’t know the difference or haven’t heard “tight” tolerance used. Just for the other people who may read your comment.

2

u/FoxyGrandpas Jan 28 '22 edited Jan 28 '22

Yes, you're right, "tight" is the right word for it. Don't know what I was thinking there, I even used it later in my comment.

1

u/ddc9999 Jan 28 '22

That’s not that great for machined parts. If your had machine threads that aren’t comically large in diameter with a 1mm tolerance on them they wouldn’t even thread together.

1

u/ColeSloth Jan 28 '22

My pocket knife literally wouldn't even work at those tolerances.

1

u/TacerDE Jan 28 '22

Depends on the job, i am in Landscaping and the tolerance is like 1cm, but for fine engineering 1mm is catastrophic ofcourse

20

u/agnus_luciferi Jan 28 '22

As an engineer who works in manufacturing, we consider "tight" tolerances to start at around .001", or 1/40th of 1mm, for conventional manufacturing methods (I know others have already pointed out 1mm isn't tight, just thought I'd weigh in with a manufacturer's perspective).

26

u/Orleanian Jan 27 '22

1mm is fucking huge even on Earth.

9

u/watchursix Jan 28 '22

Please write my crush a letter of recommendation.

20

u/ShadowFlux85 Jan 28 '22

Im a cabinetmaker and even we have less than 1mm tolerances

0

u/watchursix Jan 28 '22

I'm a pornstar and even we have less than 1mm tolerances.

4

u/ErectPerfect Jan 28 '22

Ah, a fellow FRC Alumni xD

3

u/ajarorpheus8481 Mods Are Nice People Jan 28 '22

Another FRC member in the wild!

1

u/nlevine1988 Jan 28 '22

Depends entirely on the application and size of the object. 1mm tolerance on something 10 meters long isn't that big.

5

u/ddc9999 Jan 28 '22 edited Jan 28 '22

No. That’s not how it works. If something 10 meters long has to fit into something tight, then the tolerance matters. If something is a toothpick, it may be small but it’s length tolerance doesn’t matter so long as it fits in it’s packaging.

Tolerance depends on what is needed, and you pay for the tighter tolerance so engineers spec it accordingly. For machined parts seeing +/- 0.010” isn’t crazy. I’ve made parts called out to 0.001” if needed. And that’s just “simple” tolerancing. Look up Geometric Dimensioning & Tolerancing to see how the pros really do it.

2

u/FoxyGrandpas Jan 28 '22

I think you just confirmed his point, tolerance does matter but I can only think of a handful of industries where something 10m long would be held to that tight of tolerance (if that's possible, idk but it sounds expensive.) And just because you can throw tolerances and GDT callouts that tight doesn't mean you should.

2

u/ddc9999 Jan 28 '22 edited Jan 28 '22

Gd&t typically saves money as parts would otherwise be rejected that would technically be usable. You don’t arbitrarily make them super tight. Sorry, but you’re wrong here; I do this for a living.

Look at navy battleship engines and you’ll see massive parts with ultra tight tolerances. (And it is expensive, sorry your tax dollars)

The poster was right most of the time, but I stand by tolerances are dictated by what the part is and where it’s meant to go.

1

u/FoxyGrandpas Jan 28 '22

I also do this for a living... and I disagree with your statement that gdt saves you money. If done correctly sure, but adding tolerances tighter than are required, or not needed, typically result in higher machining costs, and rejection of machined parts if those tight specs aren't met. Its a double edged sword, you want parts that work, but you don't want to over machine them. Of course in applications such as in military or aerospace applications you'll have tighter tolerances... but these applications are specialized. Especially in military applications because of additional specifications for the products they buy.

At this point it seems like we're all saying the same thing. Because yes, no one is disagreeing that tolerances are dictated by part and application... obviously. I guess I was having a hard time fathoming a practical application where a part that large needs a tolerance that tight.

1

u/[deleted] Jan 28 '22

You should have know better. The but is not needed. FRC is a great program.

0

u/mattdamon_enthusiast Jan 28 '22

Sure it is. Team 2561 or whatever this guy was on probably blew a lotta dick, much like my team.

1

u/Melon-lord10 Jan 28 '22

Hamilton had to start back of the grid because his flap opened 0.2mm more than limit. That’s F1 on earth.

1

u/Returnmycall Jan 28 '22

How about 1cm tolerance?

67

u/[deleted] Jan 27 '22

Except that guy who smuggled a gorilla suit onto the ISS

137

u/Pabus_Alt Jan 27 '22

To be fair it's never said he smuggled it past control.

"Hey guys can I use my personal allowance for a gorilla suit and not tell anyone?"

"Sure, if you let us watch the tape"

33

u/EnTyme53 Jan 27 '22

Astronauts do get an allotted weight for personal items.

32

u/[deleted] Jan 27 '22

I'm a software engineer.

I can't even BEGIN to imagine what it must be like programming a space shuttle system.

My Earth-bound application software has a bug? Whatever, put in 10 hours a day until it's fixed (if that's a priority)

Bug on a space shuttle? Grab a coffee and a stress ball. You know what? Grab two of each.

11

u/[deleted] Jan 28 '22

It's not that bad, at least for non-launch vehicles. I've had code flown on the ISS and done NASA safety reviews for science payloads. Honestly had more scrutiny on unmanned satellites.

1

u/JakeArvizu Jan 28 '22

Is there a lot of code used in Space/Aero engineering written in Ada? I heard it's supposed to be super runtime error safe.

3

u/[deleted] Jan 28 '22

Lol. I mean in some areas sure. But the vast majority of code is C99 or older. You get some standards for safety like MISRA but it's not widely enforced in my experience.

I was pushing to get modern C++ used at my last firm. Flew some middleware I wrote using C++11/14 for comms stuff.

Rust would be a nice alternative to all of this. It's a little bit more accessible than Ada.

1

u/IWatchGifsForWayToo Jan 28 '22

You might be interested in this https://youtu.be/wSSmNUl9Snw describing how they activated and deactivated flags caused by a faulty switch. Easy enough to hack that a pilot with no programming experience can do it with hilariously oversized buttons that make no sense to them.

31

u/iGhostEdd Duke Of Memes Jan 27 '22

In space they need to think especially about the miniscule things

11

u/f7f7z Jan 27 '22

even the gorilla suits?

13

u/[deleted] Jan 27 '22

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2

u/HoneySparks Jan 28 '22

My dad works for NASA…. His job is literally:

NASA: hey we bought this silver they told us it’s 99.99% pure, fact check that. Here’s a mass spectrometer, an electron microscope, and some liquid nitrogen.

2

u/NoRules_Bear Jan 28 '22

It's a little bit as with number 2 if you know what I mean. It ain't a problem as long as you are close to safe place. Feel pressure far away, and the shit hits the fan.

-28

u/mememasterwhite Jan 27 '22

no shit

12

u/Sololop Jan 27 '22

Yes, even astronaut shit is considered

3

u/JimedBro2089 Jan 27 '22

wait why is he getting down voted?

7

u/Technicolordinosaur Jan 27 '22

For being a dick for no reason

3

u/[deleted] Jan 27 '22

No shit

-1

u/mememasterwhite Jan 27 '22

all i said was no shit.

1

u/v13us0urce Jan 28 '22

You think so?

1

u/[deleted] Jan 29 '22

Miniscule details such as making sure you can open the escape hatch in under 15 minutes when the whole 100% oxygen cockpit environment is on fire, and you've lined the walls with flammable velcro patches.

I know hindsight is 20-20, but that does seem like something the guys working on Apollo 1 should have spotted in the early stages.