I remember asking once, we don’t we just shoot our surplus trash off into the sun and was told that by the cost of launching it outweighs the benefits. Fair!
But what about all of the old satellites and space stations? Why don’t we just send a giant magnet around the earth once or twice and then slingshot all that space junk into the sun and thus giving all science fiction writers (when they return from their strike) a plot point they can no longer use in their film scripts?
Seriously though, without the cost of breaching the atmosphere, this seems really cheap to pull, why don’t we do this? Why isn’t this a standard thing?
Kerbal Space Program certified astrophysicist here.
Getting into earth orbit is hard enough. Hitting the sun is also surprisingly hard. Well, hitting it is in itself not that hard, but carrying the amount of fuel needed is.
To hit the sun you need to hit an escape trajectory from earth. One you’re in low earth orbit, thos isn’t THAT hard, but it requires a lot more fuel than one would normally pack into a normal satellite.
And once you’ve escaped earth, that’s where the real fuel expenditure has to happen: do nothing, and you’ll remain roughly coplanar with earth (and in all likelihood eventually be recaptured by earth gravity). What you need to do is to burn retrograde, as in slow down your orbit, so you start falling straight towards the sun instead.
Wait, I’ve just met my first celebrity on Lemmy. I need to keep this moment stored in my memory banks.
Okay, my first question isn’t the space debris all in earth’s low orbit already?
Second question, can’t you ride the orbit and then use a tiny thruster to leave the atmosphere and follow that trajectory straight towards the sun. I imagine the calculations needs to miss every planet between us and the sun wouldn’t be simple, but thirdly, technically this should be possible right?
Lol space is so big that even if you try, it’s hard to hit a planet. Also “ksp certified astrophysicist” is a joke, ksp is a video game which teaches you a lot about orbital physics. It’s a common joke in the Spaceflight community that ksp teaches you more about astrophysics than an actual job.
Correct. I’m an IT dude by trade.
I’m a physicist and I love KSP. You can learn a lot of things about orbital mechanics from textbooks, but KSP offers a great way to see how everything works. One of my TAs actually used it for teaching, to illustrate homework problems.
The problem with picking up space trash is that it’s spread all over in all sorts of orbit. To pick up said trash, the spacecraft will have to alter its own orbit to intercept trash.
The issue isn’t so much the size of the thrusters, but the amount of fuel needed. In space, everything coasts along its current orbit, and to go elsewhere you need to expend propellant to alter your orbit. Either by burning loads of fuel in a short amount of time, or with the thrust spread out over a longer burn time.
And when you’re finally ready to head into the sun you need to escape earths gravity well, which takes abbunch.
And to hit the sun you will in effect have to burn enough fuel to cancel out the orbit that you inherited from earth to begin with. I don’t have the DeltaV numbers in my head, but the fuel cost is immense.
Think of it as a representation of how much energy is needed for orbits. To get to the moon you need about 1.7 km/s of delta v. To get to sun you need 30 km/s of delta v. To escape our solar system you only need 18 km/s of delta v.
Think of it this way. The earth is moving horizontally to the sun at 29.78 km/s (107,200 km/hr). In order to hit the sun you have to cancel all of that movement otherwise You’ll miss the sun and enter a new elliptical orbit.
Hmmm, I was thinking we could slingshot our own orbit. Use the centrifugal fly South and use a couple thrusts to point towards the sun. I was clearly over simplifying it.