4 ms·

Most people sleep at the same time in one given geography, but if you're looking at the world, those times are pretty well distributed. Assuming I'm sleeping 8

Most people sleep at the same time in one given geography, but if you're looking at the world, those times are pretty well distributed. Assuming I'm sleeping 8 hours a day, even the continental US only has 5 hours per day when everyone is asleep when you account for time zones. But APAC, ME/Africa, and Europe are all pretty reliably awake at that time.

cortesoft 10y ago
Yeah, but that doesn't mean you can just put all the satellites right above the part of the world that is awake - so you are still going to not have a perfectly efficient system.
- oillio 10y ago
  Why not? I wonder if you could construct a polar orbit that followed the daylight around the earth. Add higher concentrations of satellites to the orbits that correspond to the higher traffic hours of the day.
  - mnw21cam 10y ago
    Yes, it's called a sun-synchronous orbit https://en.wikipedia.org/wiki/Sun-synchronous_orbit https://en.wikipedia.org/wiki/Sun-synchronous_orbit The exact orbit has to be arranged so that it precesses once a year, keeping it aligned with a particular local time of day. "Typical sun-synchronous orbits are about 600–800 km in altitude, with periods in the 96–100 minute range, and inclinations of around 98°"
    - Symmetry 10y ago
      There are 5 planes of 75 satellites planned by SpaceX later on for 81 degrees inclination which might be sun syncronous during the day but the initial 32 planes of 50 satellites are all headed for 53 degrees inclination which I'm sure isn't. You can't have sun synchronous orbits anyways for those satellites providing coverage during the night.
      - mnw21cam 10y ago
        > You can't have sun synchronous orbits anyways for those satellites providing coverage during the night. Um, what? Of course you can.
        Symmetry 10y ago
        Well, I mean you can put a satellite in orbit so that it always goes over the equator at midnight local time. But then it's solar panels will never get any juice and it won't function.
        mnw21cam 10y ago
        If it's in a sun-synchronous orbit when it is crossing the equator at midnight local time, then it will also cross the equator at midday local time on the other side of the world. We have weather satellites in this exact orbit right now.
        Symmetry 10y ago
        You're right, my mistake.
    - ooqr 10y ago
      Yet another reason to do away with DST

cortesoft 10y ago

Yeah, but that doesn't mean you can just put all the satellites right above the part of the world that is awake - so you are still going to not have a perfectly efficient system.

oillio 10y ago
Why not? I wonder if you could construct a polar orbit that followed the daylight around the earth. Add higher concentrations of satellites to the orbits that correspond to the higher traffic hours of the day.
- mnw21cam 10y ago
  Yes, it's called a sun-synchronous orbit https://en.wikipedia.org/wiki/Sun-synchronous_orbit https://en.wikipedia.org/wiki/Sun-synchronous_orbit The exact orbit has to be arranged so that it precesses once a year, keeping it aligned with a particular local time of day. "Typical sun-synchronous orbits are about 600–800 km in altitude, with periods in the 96–100 minute range, and inclinations of around 98°"
  - Symmetry 10y ago
    There are 5 planes of 75 satellites planned by SpaceX later on for 81 degrees inclination which might be sun syncronous during the day but the initial 32 planes of 50 satellites are all headed for 53 degrees inclination which I'm sure isn't. You can't have sun synchronous orbits anyways for those satellites providing coverage during the night.
    - mnw21cam 10y ago
      > You can't have sun synchronous orbits anyways for those satellites providing coverage during the night. Um, what? Of course you can.
      - Symmetry 10y ago
        Well, I mean you can put a satellite in orbit so that it always goes over the equator at midnight local time. But then it's solar panels will never get any juice and it won't function.
        mnw21cam 10y ago
        If it's in a sun-synchronous orbit when it is crossing the equator at midnight local time, then it will also cross the equator at midday local time on the other side of the world. We have weather satellites in this exact orbit right now.
        Symmetry 10y ago
        You're right, my mistake.
  - ooqr 10y ago
    Yet another reason to do away with DST