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
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Are you the stoner? One of you can be Neil degrass Tyson? That physics dude… Astro or even heck it could be Stephen hawking or anyone you probably need Superman to be one of the friends present
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It seems difficult to have enough bottled oxygen to deorbit yourself, but maybe doable.
The MMU backpack units on the space shuttle had a total delta v of ~30 m/s. You need about three times that amount to deorbit from ISS. So imagine you need 3 MMUs give it take worth of expendable propellant oxygen, and you can do it. (The MMUs used nitrogen, but for this purpose oxygen is pretty much the same.)
After you deorbit, you will of course burn up on re-entry with no heat shield. But it might be conceivable to design a personal heat shield surfboard.
You could also avoid the whole burning up things by braking a lot more during the deorbit maneuver. But instead of 100 m/s, you need to slow down by more than 7000 m/s. That's quite a few more MMUs worth of gas. But if you do that, then you're essentially making a free fall jump from space, which has more or less already been demonstrated.
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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
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The answer to this depends on how much the magic device with the oxygen weighs.
Also just going to set aside anything to do with sky diving and space suits and having friends and everything else that I don't know anything about.
I only know this from playing Simple Rockets on android but basically you direct your thrust in the direction you're moving in order to reduce your velocity, and you'll fall down to earth.
Think of an orbit as the balance between falling towards earth and zipping past earth. If you fly past too fast then you just fly past and maybe the gravity pulls you a bit but not much. If you fly past too slow the gravity pulls you down to earth and you crash. If you fly past at the same speed you fall towards earth the two directions balance out and you end up just spinning around earth.
Therefore, If you're in a stable orbit on the space station, and then you slow down, you'll start to fall down towards it instead of "falling" around it in an orbit.
If you only slow down a little bit you'll start moving towards Earth but you'll be moving way too fast for an unshielded human to enter the atmosphere without burning up.
You'd have to slow yourself down, by directing thrust towards the horizon you're headed towards, enough so that you're not going fast enough to burn up.
Whether or not you can slow down enough, quickly enough, depends on how much thrust your magic device can provide and how much that device makes you weigh.
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What is it that makes you “burn up” on reentry? Is any of that avoided if you can decelerate yourself from going sideways… apologies I don’t know what to call it but you are like a baseball at that point going sideways across the yard relative to flat ground on earth I think.
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If you fall straight down so I guess that means straight down is still like 24000 mph or whatever the earth is rotating… but if you slow yourself down would you still burn up?
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The energy that makes you burn up is your own kinetic energy. The "small" deorbit burn slows you down just enough to touch the atmosphere, but you're still going nearly full speed: 7200 m/s. Around 30,000 km/hr.
If you slow down more in space, so that you enter the atmosphere at low speed, you don't burn up. But you need a whole lot more backpacks to handle the full speed. It's cheaper and burns less gas if you use the air to slow down.
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The weight of the device let’s say is 20 bananas and so that makes 2 fit astronauts and a stoner. Nobody knows why the stoner was on the space station to begin with.
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Do rockets aim straight up as they try to leave earth, why don’t they burn up on exit too
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The only reason things burn up when they enter the atmosphere is because they're moving so fast that the friction from the air generates too much heat.
So yes, if you slow yourself down enough then you could just float down like a feather in the wind.
I have no idea how fast is too fast.
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I think it would be cold I don’t know would a human size piece of space debris burn up?
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The issue here is that the ISS is travelling about 17,500 mph. Even if you somehow stopped yourself immediately (watch The Expanse to see what happens what happens when someone traveling very fast sudden comes to a complete stop) I think you would be falling too fast by the time you hit the atmosphere to fall safely. Heat starts being an issue over mach 1 and you'll be moving much fast than that. An unshielded astronaut suit would burn up quite fast in those conditions.
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Would it help if the station was in geosynchronous orbit
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Then it would be even higher up and you would be going even faster on re-entry
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Rockets do not aim straight up when they are leaving. They go straight up for a few seconds, and then they tilt over in the desired direction to pickup speed.
They don't burn up on the launch because they time the tilt over maneuver so that they get above nearly all of the atmosphere before they start picking up serious speed.
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Nope. You would hit the atmosphere moving even faster
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Everything burns up regardless of size. Big things might not finish burning by the time they hit the ground.
You need either enough thrust to slow you to ~mach 2, or a heat shield to do the same by aerobraking.
It's called aerobraking for a reason: you're using friction to turn kinetic energy into heat to slow down, but that heat goes into the air and your heat shield instead of brake pads and rotors.
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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.
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It's friction with the air.
You've experienced a strong guest of wind, now multiply that by 700x. At some point the temperature of the air is meaningless. The impact of you on those air particles gives them soo much energy they get white hot and radiate heat as energy, thereby heating you up. Like standing next to a fire.
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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.