this post was submitted on 23 Feb 2025
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If you had to jump off of the space station with with your friends, and all you could bring with you were your spacesuits, parachutes for each of you, and you had a magic device that had enough oxygen (midwest.social)
submitted 12 hours ago* (last edited 11 hours ago) by DancingBear@midwest.social to c/asklemmy@lemmy.ml
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for you to survive the journey. If you could somehow spray the oxygen to get you close enough to Earth to use the parachute and land safely, how would you do it?

Edit: and how much oxygen would it take to spray, would you need to use to oxygen to slow your decent? This is assuming the amount of oxygen you have would be the same amount required before you naturally deorbited like a junk satellite or something. So like, you don’t have any food so you wouldn’t make it that long, but that’s how much oxygen you magically have…. Could you make it out alive? And how?

Edit 2: one of you has a cool clipboard and space pen that astronauts have that you can do math with.

Edit 3: one of you is a stoner.

Edit 4: if the space station was in geosynchronous orbit, could an astronaut jump down off of it?

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[–] AbouBenAdhem@lemmy.world 26 points 11 hours ago* (last edited 11 hours ago) (1 children)

Jumping off the ISS wouldn’t cause you to de-orbit—it would just put you in a slightly more elliptical orbit that would eventually intersect the ISS again.

And if you did get into an orbit that took you down into the atmosphere, no parachute would save you—parachutes are for slowing to a safe landing speed from terminal velocity, not from orbital velocity. You’d need to go through atmosphere too thin to fill a chute, but still fast enough to burn you up.

[–] DancingBear@midwest.social -1 points 11 hours ago (2 children)

Right but we have the oxygen. Which direction should we jump? If we jumped forward we wouldn’t run into it again but we could get further away faster if we jumped away I think

[–] cynar@lemmy.world 11 points 8 hours ago

Orbits are all about speed, not height. To deorbit, you need to reduce your speed at the highest part of your orbit. This will lower the lowest part. You jump off the back. You would need to jump FAR harder than your legs are capable of though.

Unfortunately, the sheer speed will kill you, without shielding. As you hit the air, you are going so fast, the air can't get out of your way. You compress it ahead of you, that heats it up. It gets hot enough to melt most metals. The air will cook you, long before you get slow enough to use your parachute.

For comparison, terminal velocity (max speed you reach falling) is around 200km/h. Orbital velocity is 7km/s or around 25200km/h.

[–] untorquer@lemmy.world 4 points 10 hours ago (1 children)

No. Jumping forward increases your elevation at the far orbit. Jumping back decreases it. But you'd end up back on where you jumped in one orbit either way.

[–] Xavienth@lemmygrad.ml 2 points 9 hours ago

The intersection point of your orbit would be fixed in space, but because you have added or removed energy from yourself, your orbital period will be slightly different. When you come back around, the station will be a little bit ahead or behind where it was last orbit.

With each subsequent orbit, this gap would grow until you're on completely opposite sides of the planet at the intersection point, and then it would shrink. Eventually, the difference would come back around to zero and you would hit the station.

In theory, anyway. In reality, perturbations in your and the ISS' orbits would almost ensure you never hit it again for a very long time, if ever.