#### I am not <s>an orbital</s>any kind of scientist

"Space," it says, "is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.

HHGTTG

Rocketry is just using an explosion to move something, the science part is controlling the result. Orbital mechanics is understanding what happens when you get there.

Even orbital space is a bit bigger than your shopping mall car park, throwing some really dodgy numbers pulled straight from google (6371 km for earth radius - doesnt even mention flattening etc, 804 km for altitude, for r = 7175 km) we get a sphere with a surface area of 6.47 x 10^8 square kilometres - so even if you convert all of Wales to a parking lot, it is still over 31 kiloWales.

Thats just one level or altitude band, or whatever the technical name might be.

So there is plenty of space up there (sometimes I'm just so funny I cant believe it myself) but how much room does each satellite need, and how many are there?

To be at an orbital altitude you need to be travelling at the orbital speed (ignoring eccentric orbits for the sake of simplicity), so everything at the same level should be travelling at the same speed, like traffic on a highway. Would be nice if they were all travelling the same direction, as well...

Since they dont, each satellite pretty much requires its entire orbital path to itself, again using numbers that have no basis, we will call the orbital path a cylinder 100m high with radius 7175 km, we get 2254 square km, or 108 milliiWales

Continuing the theme of broad baseless assumptions and ignoring inconvenient details, we should be able to fit over 300 000 satellites into the 500 mile altitude band alone, although intersections would be constant and actual collisions a regular occurrence.

This is just idle musing and I really should start doing some work.

icon for the beer coaster I should have been doing the calculations on.