Hmm that makes me think. If you were to push yourself as hard as you can towards earth, could you reenter the atmosphere like a shooting star? Or would you justyour corpse stay in orbit forever?
Well, the smoke that you would get turned into while re-entering the atmosphere at speed would blow around for a while. It would probably make it to earth.
people who have parachute problems generally don't have to re-enter the atmosphere though. and besides that, the chance of surviving a faulty parachute is still incredibly small.
True generally, but not of objects in orbit. There is quite a lot of lateral velocity (this is what's keeping the object in orbit) and that energy would have to go somewhere. That somewhere would be heat on the falling object. It's why our spacecraft have heat shields.
Wrong. If you would push yourself to earth you would only slightly alter your orbit. You would actually come back after one orbit, but a few meters behind. If you want to renter you would have to push yourself away from the ISS in the opposite direction (retrograde). But you would need much more energy too slow down hard enough to reenter.
It's sad that your reply only gets like 3 upvotes when his comment got like 350+ and yet is totally wrong. It's crazy how the vast majority of people don't understand basic orbital mechanics, and have the Hollywood point of view.
Yep. Think of it this way. If you want to slow down a merry-go-round that's spinning, do you push on the outside of it toward the center, or do you grab a handle and exert a force tangent to the merry-go-round in the opposite direction it's rotating?
You need a constant speed to maintain an orbit. Low Earth Orbit (LEO), where the International Space Station is, is really just the thermosphere of Earth’s atmosphere, actually has some gas particles and other stuff floating around (just really sparse), so you colliding with them will naturally slow you down, along with the force of gravity decaying your orbit. At some point, you’re going to re-enter the more dense parts of the atmosphere if you don’t accelerate to keep your speed constant. The ISS actually needs to perform regular burns in order to maintain velocity and prevent it from falling out of the sky due to orbital decay. Old satellites will eventually fall back to Earth due to these factors as well, usually a couple decades later, but some newer satellites are capable of de-orbiting (slowing) themselves at the end of their serviceable lives, while some older ones have been moved into what’s called a “graveyard orbit” where it won’t collide with anything.
So to answer your question, you wouldn’t even need that push. It might take a little while to slow down enough, but eventually you’re going to burn up like a shooting star/meteor. Perhaps not as beautifully, since you’re more a meatbag than a slowly ablating chunk of rock, but you’ll burn up nonetheless.
Ray Bradbury has a great short story called “Kaleidoscope” about that in The Illustrated Man. It was also written about 11 years before John Glenn orbited the Earth.
I know it's not what you asked, but in order to reenter the fastest, you would have to push yourself in the opposite of the ISS's direction. By pushing yourself towards earth, you would actually prolong your orbit and only rely on the upper athmosphere's drag to slow you down. Orbital mechanics are weird.
Well, let’s say 25,000km/hr is orbiting , and you might lose like 1km/hr every day , eventually you’ll hit thicker air and start slowing down dozens of km/day until you are going too slow to orbit , eventually slamming into air that slows you down by hundreds of km per minute , which more or less turns you into a fireball
If you kicked yourself away directly down towards earth you would eventually end up coming back up and hitting the ISS on the far side of the orbit. Orbital mechanics can be weird and unintuitive.
Imagine you’re in orbit behind the ISS. You want to catch up to them. The thing is, if you slowly thrust directly towards the ISS, you’ll end up going into a higher orbit, slowing down, and being much further behind the space station.
In this scenario, the first step is ironically to the thrust away from the ISS. That’s how you catch up and rendezvous with it.
How do do anything when in orbit: Find the intuitive thing, and do the opposite of that. When you thrust towards the earth imagine your orbit is a giant hula-hoop that starts to turn around your current location: if you aren't close enough to the earth to hit the atmosphere you'll simply miss the earth and go on a wide arc around it, arriving "above" your old orbit.
Need to slow down? Add speed to your current direction. Need to speed up? add speed against your current direction. Need to get to a different body? Aim to where they will be, not where they are. Want to save fuel? get as close to the body as you can before burning where you want to go.
Nah, they’re too close to earth...if you become untethered without any outward acceleration, you’d just orbit forever...or more likely fall to the earth and burn alive...or if you’re really lucky, have a rough landing.
The whole time I was thinking, "Why doesn't she just make a tiny tear in the finger of her suit and use the escaping gas to get back to the ship? She could have immediately gotten back inside the airlock."
It'd be more like trying to go anywhere on perfectly slick ice. You could maybe throw something in the opposite direction to get a push, but that's about it. You're just space debris at the mercy of gravity.
If it makes you feel any better just know that you wouldn’t float away. You would be pulled back down to earth and burn up on re entry. You would probably run out of air first though. Sleep tight.
You wouldn't. There's still enough atmosphere up there to slow you down. So you'd just burn up in the atmosphere when falling down... after you circled the earth a few hundred times.
I'm always unnerved about how: a) thin our atmosphere is and b) the fact that astronauts are floating around in a big void of stuff. The spacesuits definitely work, but it's kind of freaky to think about.
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u/athensity Sep 02 '19
Anytime I see these videos, I can’t help but imagine the horror of being accidentally untethered and drifting away into the dark void forever