Timeline for Skydiving... From a space station
Current License: CC BY-SA 3.0
10 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Nov 12, 2017 at 1:27 | comment | added | Loren Pechtel | The boosting effect on the space station isn't a problem--it's experiencing drag anyway, the boost it gets from sending someone home simply saves a bit of stationkeeping fuel. | |
| Oct 19, 2015 at 4:20 | comment | added | hobbs | If you have a lifting surface then, with the shallow reentry, you can control your rate of descent to keep your speed commensurate with your altitude. If you have enough time (oxygen) and precision control, the ideal would probably be a skip reentry. | |
| Oct 19, 2015 at 4:17 | comment | added | hobbs | Peak Gs are actually much lower with a small deceleration and shallow descent — you hit the atmosphere at a very high speed, but you hit a very thin bit of atmosphere that can't decelerate or heat you very much. The drag from that then lowers your perigee and also your speed. If you kill all your orbital velocity while still above the atmosphere, you plunge straight down into the atmosphere and are into the dense part in short order. As the density increases, your terminal velocity rapidly decreases and the deceleration becomes extreme. | |
| Oct 18, 2015 at 16:26 | comment | added | Tim B | This also has the problem that decelerating the astronaut accelerates the mass driver. You need to throw something the other way. | |
| Oct 18, 2015 at 13:24 | comment | added | user | @MiloBrandt The 117 m/s for IIS orbital altitude sounds about right. See How could a 90 m/s delta-v be enough to commit the space shuttle to landing? on Space Exploration. (Full disclosure: it's my own question.) Of course, the Space Shuttle was pretty well built for re-entry; it'd take some serious retrofitting to be able to do the same thing with, say, basically just a spacesuit. | |
| Oct 18, 2015 at 10:47 | comment | added | Paŭlo Ebermann | @MiloBrandt the acceleration of the satelite might actually be useful in order to stabilize its orbit (currently ISS needs to be pushed up ever once in a while). | |
| Oct 18, 2015 at 8:56 | comment | added | Taemyr | I don't think an answer to this question can be complete without discussing MOOSE. | |
| Oct 18, 2015 at 1:20 | comment | added | Thucydides | Exactly the point. If you are still moving at many kilometres a second when you hit the Earth's atmosphere, then you will rapidly burn up on reentry. If you want to slow down enough to prevent that, then you will have to decelerate quite a bit more (and provide more inputs to the space station, something I failed to mention in the initial answer). | |
| Oct 18, 2015 at 1:15 | comment | added | Milo Brandt | For reference, according to my (reasonably rough) calculations, a deceleration of 117 m/s would be sufficient to put an object from the ISS into an orbit that contacts Earth's surface. The good news is that with a very large, but not totally unreasonable gun, this could be done with safe accelerations. The bad news is that with this orbit you'll hit the atmosphere moving at over 8000 m/s. The other bad news is that you'll have accelerated your satellite, so if it needs to be in a particular orbit, it'll have to correct with rockets (and apply the same impulse as you would've needed) | |
| Oct 18, 2015 at 0:28 | history | answered | Thucydides | CC BY-SA 3.0 |