4 ms·
The thing to remember is in a low earth orbit, your orbit has you moving around 8 kilometers per second. So even before we start getting to the counterintuitive
by fennecfoxen 5y ago
The thing to remember is in a low earth orbit, your orbit has you moving around 8 kilometers per second. So even before we start getting to the counterintuitive parts (higher is slower, lower is faster, etc) take a moment and think about that 8km/s figure by itself.
Consider a token 1% of that amount: 80 m/s (~180 mph). Do you think your orbit has more than a 1% margin before your craft plunges into the atmosphere? (I certainly expect it does). Does this seem like a reasonable speed you could get to using your personal astronaut propulsion device? I don't actually know, but it certainly challenges my image of astronauts zooming around a space station at speeds that would make a kick-scooter look fast.
- jkelleyrtp 5y agoSince there's no drag, you can accelerate as much as you want given the fuel in your pack. In fact, propellant is talked about in terms of Detla-V (delta in velocity). It seems like the first models of cosmonaut suits gave about 70 m/s of DV while the most recent astronaut MMUs give about 25m/s [1]. So, I don't think an astronaut could de-orbit themselves with just their suit alone. [1] https://en.wikipedia.org/wiki/Manned_Maneuvering_Unit https://en.wikipedia.org/wiki/Manned_Maneuvering_Unit
- kayodelycaon 5y agoThere is drag on the International Space Station.
- fennecfoxen 5y agoThere is, but the drag is so small that they operate an entire space station in that orbit. It'll be quite some time before it starts to make a difference.
- deleted 5y ago[deleted]
- inglor_cz 5y agoThere is non-0 drag at this distance from Earth and it is the main reason for orbital decay. https://en.wikipedia.org/wiki/Orbital_decay https://en.wikipedia.org/wiki/Orbital_decay But from a POV of an astronaut fiddling around with his propulsion unit, this drag is low.