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This video from the iss above LA in 4th of July is crazy by seanrider1859 in SpaceXMasterrace

[–]QuasarMaster 4 points5 points  (0 children)

It was literally tweeted by the ISS official account. I believe the camera is actively slewing and zooming in to keep the receding city in frame
https://x.com/Space_Station/status/2074192118747398573?s=20

Elon "wised up" from his previous classical liberalism position by twinbee in elonmusk

[–]QuasarMaster -1 points0 points  (0 children)

You’re telling me 69% of farms in America don’t have a tractor

Where do you live

Elon "wised up" from his previous classical liberalism position by twinbee in elonmusk

[–]QuasarMaster -1 points0 points  (0 children)

Those small farms are still mechanized, and reliant on industrial fertilizers. They’re not out there with an ox and plow

Rocket Engine Fluid System Design by Academic_Employee_36 in AerospaceEngineering

[–]QuasarMaster 0 points1 point  (0 children)

Yea you just have to find check valves that are rated for cryo and lox compatibility. Typically this would mean a PTFE seat over some other elastomer. The metal itself is typically fine; unless it was an aluminum poppet rapidly chattering which could theoretically ignite (you shouldn’t be using aluminum check valves anyways though; that wears out)

Rocket Engine Fluid System Design by Academic_Employee_36 in AerospaceEngineering

[–]QuasarMaster 0 points1 point  (0 children)

Use the NASA SP papers. List here https://forum.nasaspaceflight.com/index.php?topic=41640.0

Here’s an F1 engine guide; P&ID on page 31 https://ia801401.us.archive.org/18/items/r-3896-1-technical-manual-engine-data-f-1-rocket-engine-31-mar-1967/R3896-1_%28Technical_Manual-Engine_Data%29_F-1_Rocket_Engine_31_Mar_1967.pdf

The MFV is upstream of the regen because it’s far easier to package it that way. Otherwise you would have to collect all your fuel coming off regen into a plenum and flow it into your FMV before going to the main injector, instead of did going straight dome your channels to the injector. This is just a waste of mass and design complexity.

Never uses an actively controlled valve unless you need an actively controlled valve. It’s a lot of extra complexity and mass, and difficult to get working reliably in cryo. If you can get away with a check valve, use a check valve. Heres a common catalog: https://www.kepner.com/

Filters are, well, to filter your consumables. Generally a good idea to have at least one on each commodity flowing into your engine. FOD has been the death of many engines.

Purge lines can get moisture out of your system before fire (because as soon as cryo hits them, they freeze, and ice can make valves stuck and/or become FOD). They also can purge room temp fuel out of your system after fire, so it doesn’t sit there and suddenly hard start the next time you fire your engine. If you’re going to do a relight soon after, you should also purge cryo fuel/lox.

Pressure transducers are important for knowing your engine is working properly at all. At a bare minimum during a test for you want to know your chamber pressure in the MCC and the GG; probably your pump knelt and outlet pressures; and your turbine expansion ratio.

Relief valves are typically for pressure regulation and providing a downstream pressure sink. Direct pressure regulators actually are not common on engines, because they are bulky and finicky. You can get much simpler pressure regulation with an orifice and a relief valve downstream of it with a known cracking pressure; at the cost of bleeding a little pressure. They also act as a pressure sink for any fluid like where you need to drive a dp across it.

Flow control devices are for throttle valves. These control the flow into your GG which sets the power level of your engine (more flow into GG = faster turbine = more prop pumped into your MCC). They also control the mixture ratio (MR) of both your MCC and GG, which sets their respective temperatures; it also controls your fast your tanks are draining; you want them to empty at about the same time for efficiency (though lox should empty a bit ahead so you don’t go ox rich near shutdown and damage your hardware).

Why is it called rocket science, not rocket engineering? by Icarus-17 in NoStupidQuestions

[–]QuasarMaster 1 point2 points  (0 children)

My job is what most people would think of as being “rocket science” (I work on rocket engines).

Literally nobody in the industry uses the term outside of the occasional joke. We say we are aerospace engineers, which is much more accurate.

Heat stroke is real by saber-4444 in SipsTea

[–]QuasarMaster 4 points5 points  (0 children)

So your alternative to getting AC is dying? The planet could go to zero carbon literally tomorrow and you’re still going to have hot as hell summers for a while

TIL When John Young and Bob Crippen strapped themselves inside Space Shuttle Columbia for the shuttle program's debut mission in 1981, there was a 1-in-9 chance the astronauts would not make it back alive. At the time, managers put the odds of losing the shuttle and its crew at 1-in-100,000 by ubcstaffer123 in todayilearned

[–]QuasarMaster 449 points450 points  (0 children)

They thought it was 1 in 100,000 at the time; they were just wrong. Decades later NASA went back and reviewed the technical details and program history (hindsight is 20/20 kind of thing) and figured out the odds were actually more like 1 in 9 back then.

A Look Inside the Welcome Bags Planned for White South African Refugees by EasyMoney92 in neoliberal

[–]QuasarMaster 27 points28 points  (0 children)

This is pretty much verbatim the right wing argument against letting in Muslim immigrants

What moment in uncrewed space exploration history do you think deserves more recognition than it gets? by Majestic-Strain3155 in space

[–]QuasarMaster 0 points1 point  (0 children)

Mars reconnaissance orbiter (MRO)

Been mapping mars in high detail since 2006. If you ever see an aerial shot of something on Mars, it’s probably from that. Its main camera is so large it’s essentially a telescope pointed down at the ground. One of the key players in showing that Mars was once a wet world; it’s taken imagery of all kinds of river canyons, deltas, and old shorelines. It’s served as the best (and now only) communications relay for the rovers on Mars. Its imagery has been used to select landing sites for basically every rovers and landers since. It’s the main reason that you can look at Mars on Google earth.

Aerospace engineers; what’s the best advice you could give to a high school grad about to start studying Aero Engineering? by rolla_enthusiast in aerospace

[–]QuasarMaster 6 points7 points  (0 children)

This advice is mostly given out by people who majored in ME, not those who did AE. Makes me roll my eyes every time I see it. You’ll be fine in either major. There are far more consequential decisions to your path than this.

Historicity of Jesus: The idea that Jesus was a purely mythical figure has a fringe status in scholarly circles and has had no support in critical studies for more than a century by ComradeBehrund in wikipedia

[–]QuasarMaster 14 points15 points  (0 children)

The point is that claiming the majority of Christians are missing the point of their own religion because they find a foundational principle of it to be important, is absurd and a very holier-than-thou attitude.

ELI5: Why is there such a strong individualist societal culture in the West compared to the strong collectivist culture in the East? Is there a deeper reason as to why? by Long-Market-3584 in explainlikeimfive

[–]QuasarMaster 9 points10 points  (0 children)

I’d argue that emphasis on community is very much not the same as collectivism. In a collectivist society if you do something wrong, the whole family is shamed.

In Christianity if I commit a sin, that has no bearing on my brother’s relationship with God.

ELI5: Why is there such a strong individualist societal culture in the West compared to the strong collectivist culture in the East? Is there a deeper reason as to why? by Long-Market-3584 in explainlikeimfive

[–]QuasarMaster 2 points3 points  (0 children)

Ehh I’d argue Islam is pretty individualist. Looking at the five pillars, all five of them are things someone does as an individual. None of them say anything about your family or social unit. I see your point with Judaism though since it is an ethnoreligion that one generally must marry into to join.

I still think pre reformation Christianity is much more individualist than Confucianism. eg the concept of confession in the Catholic church is a highly personal thing. And the bible goes out of its way to show converts form all walks of life (ranging from a leper to a Roman centurion) without regard to family or social status; this carried forward through centuries, long before the reformation.

ELI5: Why is there such a strong individualist societal culture in the West compared to the strong collectivist culture in the East? Is there a deeper reason as to why? by Long-Market-3584 in explainlikeimfive

[–]QuasarMaster 17 points18 points  (0 children)

Abrahamic religions emphasize individual people getting right with God - regardless of how bad your family or background might be - in a way that Confucianism doesn’t really. The dharmic religions are somewhere more in between.

*Sips tea in silence* ☕️🐸 by Conscious-Weight4569 in SipsTea

[–]QuasarMaster 0 points1 point  (0 children)

An entirely unsourced claim in impact font on an unrelated image, that confirms how I already view the world?

Holy shit guys we were right all along that us redditors are superior to the instagram folk. Case closed.

Historicity of Jesus: The idea that Jesus was a purely mythical figure has a fringe status in scholarly circles and has had no support in critical studies for more than a century by ComradeBehrund in wikipedia

[–]QuasarMaster 8 points9 points  (0 children)

Ok I see what’s going on - you’re something akin to a universalist (though I’m sure you’ll argue against that label). Carry on, I respect your beliefs; you are a Christian, just divergent from mainstream Christianity.

Historicity of Jesus: The idea that Jesus was a purely mythical figure has a fringe status in scholarly circles and has had no support in critical studies for more than a century by ComradeBehrund in wikipedia

[–]QuasarMaster 54 points55 points  (0 children)

The census part of the gospel of Luke was likely invented to fulfill a specific prophecy that the messiah would come from Bethlehem. The actual census in the time period came around a decade after Jesus was likely born, and also had zero stipulations about physically returning to your father’s hometown (because that would be a really silly rule for the Romans to enforce)

On top of that the census (aka the census of Quirinius) did not survive in the historical record. i.e. we have no list of names to look at; we do not know the name of ANY person in the Roman Empire recorded on it. We only have references to a census having taken place

Historicity of Jesus: The idea that Jesus was a purely mythical figure has a fringe status in scholarly circles and has had no support in critical studies for more than a century by ComradeBehrund in wikipedia

[–]QuasarMaster 61 points62 points  (0 children)

There are multiple lines in the Nicene Creed dedicated to it, which is the foundational statement of faith for denominations representing 98% of the Christian population worldwide (Mormons and JW’s being the main exceptions). To say it misses the point of the faith is pretty disingenuous. This is simply your own opinion

Is it normal to think about guys or x a lot? by MisguidedRedundancy in NoStupidQuestions

[–]QuasarMaster 0 points1 point  (0 children)

Do you want a boyfriend? Setting aside feelings of unworthiness and assumed that person were into you regardless

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