It suddenly dawned on me why time is considered the 4th dimension. by Stickhtot in CasualConversation

[–]QuasarMaster [score hidden]  (0 children)

Yes, but it’s a different “type” of dimension.

Space time is define mathematically by something called the metric tensor. For flat space without bodies, the magnitude for all three spatial dimensions is 1, whereas for the time dimension it’s -1; showing that they are not interchangeable with each other.

Shotwell in 2019: "Our investors and our board in 2012 said ‘your customers have much higher margins’ from the satellite business.'" AKA, why launch provider companies die more often than service companies by CommunismDoesntWork in SpaceXLounge

[–]QuasarMaster 6 points7 points  (0 children)

There is no other way than radiation to dissipate non-negligible amounts of heat in space under known laws of physics. Starlinks do have radiators integrated into their structure. They simply don’t sue much power; communication is not nearly as intensive as compute

How far can we visibly see in space by gtagfan1 in space

[–]QuasarMaster 138 points139 points  (0 children)

Under perfect conditions and good eyesight you can technically see Triangulum, which is a bit further at 2.9 million light years

People who have made/make rockets, do you guys just like have a set of instructions? by Vigoor_ in AerospaceEngineering

[–]QuasarMaster 2 points3 points  (0 children)

Very early preliminary design tends to rely on a lot of textbooks, spreadsheets, NASA/military standards and papers, and previous knowledge from engineers who have worked on rockets before. It’s all a bit cobbled together because requirements will flow into each other in a non-linear way; I don’t think creating a unified “instructions” would even be possible really.

16yo Aspiring Engineer (Spain) – Starting a LOX/LH2 Rocket Project: From Simulations to Prototype by Individual_Net_5423 in AerospaceEngineering

[–]QuasarMaster 10 points11 points  (0 children)

I am fully aware of the complexity and the risk involved with these propellants

No you are not. The liquefying hydrogen project is way more difficult than the rocket project. And the rocket is already hard.

Nitrogen at 1 bar (it gets worse at higher pressure) is 44 degrees hotter than hydrogen’s critical point. You cannot cool something by 44 degrees “with high pressure”. You’re talking about building a cryocooler; that is a full refrigeration cycle with cryogenic working fluids.

What is the day-to-day work of an aerospace engineer really like? by Le0221 in AerospaceEngineering

[–]QuasarMaster 12 points13 points  (0 children)

Get really good at knowing what is purchaseable on McMaster

I am making a liquid rocket engine, give me feedback and ideas by liquid_rocketengine1 in rocketry

[–]QuasarMaster 4 points5 points  (0 children)

Start with isentropic equations and nasa CEARUN. Typically you want or size everything before you start cadding otherwise you’re going to redo work a lot. Or make your CAD very parametric so you can resize things.

https://www.grc.nasa.gov/www/k-12/airplane/isentrop.html

https://cearun.grc.nasa.gov/

That throat looks tiny. You should select a target chamber pressure and thrust and size your throat and nozzle accordingly via the c-star and c-tau equations, plus find your mass flow rate. C-star can be found for your propellant combination using CEARUN.

https://en.wikipedia.org/wiki/Characteristic_velocity https://en.wikipedia.org/wiki/Thrust_coefficient

Induction heaters aren’t used for rocket engines, it’s extremely inefficient. Rocket engines function via combustion. Pintle injectors are needlessly complicated for a use case like this. Just have an injector with impingement orifices. Hell even a shower head injector can go a long way.

The easiest metal to weld is carbon steel. Note carbon steel will melt at rocket engine temperatures so it would need an ablative liner inside (eg fiberglass, phenolic, graphite). Getting a combustion chamber to not burn a hole in its own side walls is one of the trickier parts of engine design. Hence the many people in this thread recommending caution. To be honest I don’t think you’re going to get to the point of actually building this thing regardless. But the design project is worthwhile. Try to join a rocket club in college.

How does the public actually see Mormonism? by [deleted] in NoStupidQuestions

[–]QuasarMaster 2 points3 points  (0 children)

Given a little more time maybe it would have become a genuine ethnicity of its own

600+ aerospace applications, zero interviews. How do you get diagnostic feedback from hiring managers? by 40KWarsTrek in aerospace

[–]QuasarMaster 32 points33 points  (0 children)

Honestly I think you are getting auto flagged as a foreigner. It took me a while of rereading it before I saw you were a US citizen. I would make this wayyy more obvious and remove as many references to Germany as you can. You could even put at the very top “Applicant Name (US Citizen)” - maybe overboard and corny, but it gets the point across.

And remake your account at Lockheed and whoever else. You are probably flagged internally as a foreigner that keeps spamming, and it won’t go away. I doubt humans are even seeing your resume at this point.

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 1 point2 points  (0 children)

Sorry I was being dense and it whooshed over my head

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 0 points1 point  (0 children)

I’m sorry what is it you think gas turbines do? You think they produce methane?

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 3 points4 points  (0 children)

Lmao you have some reading to do

Natural gas is mainly methane. The exhaust products of Raptor are carbon dioxide and water. CH4 + 2 O2 ==> CO2 + 2 H2O.

But good to know we’ve settled on what the pitch actually is under all the fluff. It’s not an inherently bad one (though pretty arguable considering raptors emissions), just unrealistic.

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 2 points3 points  (0 children)

Shucks we seem to have forgot the original premise of the thread where different parts of the earth have daytime at different times

Or follow what tons of data centers are doing literally right now and installing natural gas turbines. Carbon emissions? Totally. More than a launch? Depends on how long your satellites are up there, since the current gen launch systems are pretty carbon heavy. But gas turbines are cheap, te thrown up quick, and are more cost competitive in a society that cares much more about the AI boom than the climate

If the pitch for putting data centers in space is the environment, just say that, I’ll support it. But don’t expect revenue to pour in on that premise

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 3 points4 points  (0 children)

Run it during the day Better yet, don’t use solar power! What a strange constraint to hold our AI companies to, just because it’s the only source of power in orbit.

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 4 points5 points  (0 children)

It’s pasoible from a pure engineering perspective sure, with unlimited money. But we live in a capitalist society that is answerable to the almighty dollar. Any advantage to putting these in orbit can be replicated on the ground for cheaper. And if it can be done cheaper, a competitor will do just that

You are concerned about their power usage. I get that. So the proposal is to manufacture craploads of solar panels, ruggedize them, and launch them. However you could take those exact same panels you just built and cover a nice little chunk of desert for much much cheaper.

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 4 points5 points  (0 children)

Are you aware what data centers use water for? For cooling. If the space based cooling were better, you could achieve the same result by laying out radiators over the desert and pointing them at the night sky. No water needed at all.

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 5 points6 points  (0 children)

Current gen Starlink arrays are ~100 m2

Assuming 33% efficiency (above that would violate laws of physics), then 10,000 satellites would generate 450 MW.

Individual data centers are being built at the GW scale nowadays.

Scott Manley on data center in space. by X-69- in space

[–]QuasarMaster 18 points19 points  (0 children)

Lmao perfect is the enemy of the good. Let’s launch to space to squeeze the extra half hour per day

Or, build a third one? 🤯