/sci/ - Science & Math

>>12462118
Venus diameter is 12000km, double that for full shadow, account for thicker sections and to be safe to 24kkm which gives 4.52×10^8 square kilometer area. Assuming we are using household aluminum foil at thickness of 0.016mm which gives the total material needed at 7.232×10^9 m^3. A cubic metre of aluminum weighs 2,710kg, thus the final weight of the foil needed would be 1.96×10^13 kg or 20 Billion tons. World aluminum production is roughly 60 million tons so we would need about 300 years of build up at current rate to acquire enough metal, well at least if I didn't perform a huge mistake in calculations.

You could cut that time shorter by making a smaller shade which would freeze the atmosphere out slower, making thinner material (really no need to use household strength the foil could easily be 0.006mm (which is the thinnest film that can still be called aluminum foil) or even lower than that which would cut the material cost by a factor of 10-1000.

World aluminum foil production is somewhere in the 2-4 million ton range btw

wouldn't the first concern be melting the aluminum?

>>12462184
> double that for full shadow
How fucking retarded are you to continue writing after saying something so clearly wrong.

>>12462118
A suitably large solar shade would be four times the diameter of Venus itself if at the L1 point.

>>12462199
metals don't melt in space.

>>12462228
That's how big it has to be to offer good shade from L1, even if you want to put it closer in and use billion satellites instead basically all useful orbits spend half the time on the night side e.g. you need at least double the material to get good coverage.

Really it might even have to be bigger than that but I just used a simple aproximation.

>>12463362
>metals don't melt in space.
source: my ass

>>12463400
Sun doesn't turn into some kind of death ray in space, consider that all objects be it planets, moons, rocks or satellites all spend all day in the sun and none of those melt (well the ice comets do but they are made of pussy ice instead of chad metal)

>>12462184
>double that for full shadow
well it depends on the distance your mirror is from the planet...

>>12463362
>metals don't melt in space.

>>12463413
heat can only be dissipated by radiation in space, and a thin layer of metal would definitely melt after a while.

>>12462184
You guys know that there must be a counter solar pressure reflector to keep it in place that's as big or bigger

>>12464457
Like I said it could be bigger too, I certainly hope you didn't mean you could just "hover" a mirror right next to the planet and make it smaller that way

>>12464462
They don't

>>12464475
Yes and countless planets, moons, rocks and satellites exist in space right now cooling only by radiating heat and none of those are melting.
Space isn't magic, don't pretend to be retarded

It's pretty trivial to do the black body calculations on how high the maximum temperature would be for a piece of aluminum foil in earth or venus orbits. For instance sunny day down on the ground on earth is 1100W/m2 while in earth orbit (like on surface of the moon) it's 1300W/m2, reflectivity of aluminum foil is about 80% but you can use 50% if you want, surface 1 m2 for easy calculations and radiative surface of 2m2. Crunch the numbers and see if goes to the melting point, don't be a mutt.


>>12464496
They have been experimenting with this recently, you can use the pressure to station keep either in the orbit or in the lagrange point. You can do it passively by placing the object on an orbit that wouldn't work without the additional push but will work with it. Pretty sure one of these would be lagrange point but slightly closer to the sun for instance. If you have control mechanisms then you can even use it to gain energy quite easily bu altering the direction of the forces at specific points of orbit.

>>12462184
Well, at least it's possible with current tech to cool down Venus compared to heating up Mars.

>>12464606
Actually they are basically the same level of difficulty technologically and industrially speaking. To heat up mars you just take the same mirrors you use to cool venus but aim them at mars and you got yourself hot mars. Neither is particularly difficult, just needs lot of industrial capacity to produce the satellites and launch them.

>>12464628
How would mars keep its heat with no atmosphere?

>>12464836
Well if you increase the incoming energy with a mirror then that by default increases the temperature. If you are shuffling in say twice or thrice as much energy as mars usually receives you will certainly get a toasty planet and that's easily done with the material requirements of the venus shield.
More over the heat will melt the co2 in the poles and if concentrated could also be used to just melt the regolith to release co2 and other gasses that way to create an atmosphere.

>>12464562
lmao