- #1
Kilarin
- 2
- 0
I'm confused by something very simple and stupid. When the mass of a satellite is tiny compared to the body being orbited, we can approximate orbital velocity as sqrt{(GM)/r}
Now its obvious that as r gets larger, the orbital velocity drops. Higher orbits are slower orbits. A geosynchronous satellite orbits at around 11,038kph. But the ISS orbits at about 27,735kph.
All of this makes sense, but here I get to the part I'm being stupid on. To get into a higher orbit, you must accelerate. To get into a lower orbit you must decelerate. How does it happen that you ACCELERATE and end up going SLOWER?
Is this explained by the fact that you accelerate into an elliptical orbit and then must adjust that orbit later (presumably be decelerating?) to make it circular at a higher orbit?
Sorry, its just been too long since I took College physics and I've forgotten IMPORTANT stuff! :)
Now its obvious that as r gets larger, the orbital velocity drops. Higher orbits are slower orbits. A geosynchronous satellite orbits at around 11,038kph. But the ISS orbits at about 27,735kph.
All of this makes sense, but here I get to the part I'm being stupid on. To get into a higher orbit, you must accelerate. To get into a lower orbit you must decelerate. How does it happen that you ACCELERATE and end up going SLOWER?
Is this explained by the fact that you accelerate into an elliptical orbit and then must adjust that orbit later (presumably be decelerating?) to make it circular at a higher orbit?
Sorry, its just been too long since I took College physics and I've forgotten IMPORTANT stuff! :)