Broken_Erika
Play with me.
I do! It's when you run in circles around a Geo Metro while synching your phone and MP3 player!Even by your own admission, you don't even know what geosynchronous orbit is...
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I do! It's when you run in circles around a Geo Metro while synching your phone and MP3 player!Even by your own admission, you don't even know what geosynchronous orbit is...
The ambient temperature of space swings wildly but in the regimes the vast majority of spacecraft operate in, it never gets to 7 or 1000 kelvin. That's insane.That's absurd. The ambient temperature of outer space is 7 degrees kelvin (common myth about space being absolute zero. Certain quantum mechanics take over down there; the molecules don't just stop themselves). TYPICAL earth orbital temperatures range between -175 and 400 degrees kelvin. And you're launching $10 billion space junk in the air and parking it there. You don't get to takeoff/land/service/repeat, like your aircraft do. You can't do typical--you have to do worst-case. Materials have to work between 7 and 1000 kelvin. Come on, 75C doesn't even boil water, for crying out loud. How much do you want to bet the CPU on your computer at home was tested at 125C? And you mean to tell me your "superior", "military grade" spaceships weren't?
The 'sychronous' in geosynchronous means that the satellite is more or less stationary from the point of the ground. This means it isn't whipping around the planet every 90 minutes and swinging between night and day every 45 minutes. In fact, they are in constant sunlight for about 50 weeks out of the year (with a year long 'eclipse' season in spring and fall with nights that last an hour) and are therefore extremely stable temperature-wise. Also, they don't manuever very much and the ground stations are always able to talk to them.Meaningless to YOU, because evidently YOU do not even understand how basic ham radio works. Even by your own admission, you don't even know what geosynchronous orbit is...and then claim you "know" it doesn't take PhD's to make it happen.
Please don't leave, this is a great platform for me to space cadet and is genuinely fun. I will not be a douchenozzleAs the sharks on the Shark Tank say, "For that reason, I'm out." i hope you aren't on the program.
Please don't leave, this is a great platform for me to space cadet and is genuinely fun.
The design goal is roughly room temperature. That also tends to be close to the temperature that satellites will naturally reach equilibrium at without active thermal control. This is an unwritten rule that plays a huge role in the success of CubeSats - smaller satellites have pretty uniform temperatures and their electronics (with bare bones heater systems) can keep them alive without a ton of in depth thermal analysis. Their shiny metal or solar cell exteriors also reflect most of the excess heat away while in sunlight as well.Wait what is the "temperature" of a LEO satellite on average then? I was always under the impression that temperature being a measure of particle movement means it can be "hot" in space but since the particles are so far apart a human would still freeze. How does that work ? Nerds with an old basic physics class under their belt want to know.
It "heats" up pretty fast and gets "cold" pretty fast depending on sunlight right?
I'll move future questions along these lines to the space cadet thread.Not really appropriate for "Space Force." We should start a thread where @hobbsyoyo can space geek out and teach us all the basics of physics in space.
I'll move future questions along these lines to the space cadet thread.
Wait what is the "temperature" of a LEO satellite on average then? I was always under the impression that temperature being a measure of particle movement means it can be "hot" in space but since the particles are so far apart a human would still freeze. How does that work ? Nerds with an old basic physics class under their belt want to know.
It "heats" up pretty fast and gets "cold" pretty fast depending on sunlight right?
@hobbsyoyo has covered the engineering side and I would like to contribute a few things on the physics side.
Temperature is related to particle movement (more accurately: a particle velocity distribution), but it's primary use is to describe an equilibrium. If you have a closed system it will eventually reach a state where everything has the same temperature. If you have different kinds of particles, they may have different velocities and different energies, but you can use one temperature value to describe the whole system. This corresponds to our intuitive understanding of temperature. If you put some object outside in the shade, it will sooner or later be at the same temperature as the environment.
The situation in space is quite different: To reach equilibrium, the particles have to interact (usually with collisions). But in space there are so few particles that it takes forever for the temperature to equalize. So you can have very cold particles next to very hot particles as long a they barely interact. There are still some ways to define a "temperature" but like for any other out-of-equilibrium system, these should always come with big qualifiers - these temperatures are not a regular temperature. So if you put a satellite in space, the temperature of space actually doesn't matter that much - it won't equalize anyway. What you have to look at instead is how much energy does it gain (sunlight, heaters) and how much does it lose (mostly black-body radiation).
I am very torn about how I feel about the Space Force. I feel the idea has merit and ultimately it means more jobs in my industry. But it's also in some respects condoning the weaponization of space. I don't think this will directly lead to a ton of "real" weapons platforms but it will mean more military hardware in space in absolute terms, even if the majority of it is just increasingly sophisticated cameras and radars.
On the other hand, more military hardware in space is directly correlated to more commercial and civil projects and I don't think our society will tolerate many more space jobs programs on top of the SLS and ISS unless they have a military bent. Government spending more than just about anything can lower barriers to entry into new markets by paying full cost and then some to the private sector. Not that I'm saying this method of industrial development is the most efficient or effective or even moral, but it does work and it's one of the few routes this country seems to tolerate when it comes to direct investment into industry.
Of course, the motivations behind this effort don't have a whole lot to do with my desire for a stronger aerospace sector. Instead it's largely about paranoia related to developments and pronouncements by Russia and especially China. The paranoia isn't entirely unfounded and I do think we can do better about managing our military space programs than the current Air Force.
But with Trump's administration proving to be the most inept and corrupt in decades, I fear this whole effort will turn into a massive cash grab with no benefits to anyone except shareholders in Lockheed, Boeing, SpaceX and the like.
Most components on most satellites are not pressurized. Many of the earliest satellites were however, as they did not have sophisticated thermal modeling tools for radiative heat transfer prediction. They understood it quite fine, but it is not easy to calculate those types of problems without advance computers and software. So they made the satellites pressurized because then the heat transfer problem reduces to a more 'normal' form which they could readily design against.So does this mean every satellite is pressurized for its internal components sake? If it loses pressure due to say foreign object does that make it basically die due to temperature death?
They aren't really rumors at this point. Russia has been caught on more than one occasion in the act of flying uncomfortably close to foreign satellites. China practices against their own satellites and both have publicly put forward very aggressive space militarization plans. China and the US have recently blown up their own satellites while China and Russia each have a Space Force equivalent as well.I agree with this, my only personal reservation is the treaties we've signed in the past. There are rumors about China and Russia both messing around with satellite to satellite intercepts and such.