Timeline for Why do we not fly to space with helicopters? What are the practical altitude limits?
Current License: CC BY-SA 4.0
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| Jun 8, 2018 at 15:02 | comment | added | Taemyr | "This is the altitude where you have to fly at orbital speed to get sufficient lift." - This is not correct. At the Karman line you have to fly at orbital speed to generate lift that is strong enough to counteract gravity. This is significantly more than sufficient lift - we can see this since when we are moving at orbital speed sufficient lift would be 0N. | |
| Jun 7, 2018 at 11:15 | history | edited | Hobbes | CC BY-SA 4.0 |
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| Jun 7, 2018 at 10:03 | history | edited | Hobbes | CC BY-SA 4.0 |
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| Jun 6, 2018 at 7:47 | history | edited | Hobbes | CC BY-SA 4.0 |
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| Jun 6, 2018 at 0:19 | comment | added | Erin Anne | Not to neglect the heating effects, but the required power to turn a rotor this fast is also shocking at a glance. Each rotor blade does a 360-degree orbital plane change with each revolution of the rotor (since it's at orbital velocity). | |
| Jun 5, 2018 at 7:54 | comment | added | Luaan | @PaŭloEbermann What Hobbes said. Also note that helicopters are extremely bad at hovering. They still rely on forward motion to produce lift at a reasonable cost - if you can't maintain lift while having forward motion comparable to blade velocity, you don't even come close to maintaining lift while hovering. | |
| Jun 5, 2018 at 7:45 | comment | added | Hobbes | Hovering costs a lot of energy. If you want to spend more than a few minutes at that altitude it's cheaper to get into orbit. And for pretty much any function you want, data quality improves with more time spent there. | |
| Jun 5, 2018 at 7:41 | history | edited | Hobbes | CC BY-SA 4.0 |
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| Jun 5, 2018 at 7:33 | comment | added | JollyJoker | This answer is really confusing. At the Karman line the blades need to move at orbital speed and the Helicopter can hover in place. They don't go from 0 - 50k mph, the blades are rotating at an even speed. Anything in orbit at that height would suffer from the same heating effect; I'm pretty sure that's negligible. | |
| Jun 5, 2018 at 6:55 | comment | added | uhoh | @Hobbes see this comment | |
| Jun 4, 2018 at 19:04 | comment | added | Hobbes | The only point of flying at that altitude is to get into orbit, because then you can remain up there without using more fuel. | |
| Jun 4, 2018 at 18:39 | comment | added | Paŭlo Ebermann | Why would one have to have a forward speef of 25000 mph? A helicopter can have lift without forward speed (and if it has that speed, it already is in orbit). | |
| Jun 4, 2018 at 16:43 | comment | added | Džuris | I am not sure if it's fair to consider heating effects from the air resistance. The pressure is very low up there and I believe the actual resistance will be equal to what blades usually resist. Just as the downforce will be the same. | |
| Jun 4, 2018 at 15:42 | history | answered | Hobbes | CC BY-SA 4.0 |