Preparations are under way for a rocket test flight in Norway that could make history and give Europe greater independence from the market leader in orbital launches, the United States.
Isar Aerospace says it is planning to launch on 24 March between 12.30pm and 3.30pm CET, weather permitting.
This is an absolute basic necessity for a European Starlink, isn’t it?
Well, to be able to independently launch it: yes. But once the satellites are up, who cares about the car dealers-in-chief?
& There’s already Eutelsat; their satellites already seem to be providing internet much like Starlink: https://www.eutelsat.com/de/satelliten-dienste/satelliten-internet-breitbanddienst.html
Eutelsat has geosynchronous orbits, which allows them to provide service over a much larger area per satellite and doesn’t require very many satellites to serve a consistent geographical area as the earth rotates and the satellites orbit the earth.
Problem is, though, geosynchronous orbit is 35,786 km altitude. Light travels at 3.0 x 10^8 m/s. So any signal takes 120ms to get to the satellite, and 120 ms to return. Any signal is going to have a 240ms latency at a minimum, and that’s just physics.
Starlink satellites have an altitude closer to 600 km. Light only takes about 2ms to get to that altitude, and 2ms to return. So the satellites add only about 4ms, which makes for easier and more seamless communication.
In order to compete with starlink for most typical Internet applications, it’ll require a bunch more satellites orbiting at much lower altitudes.
Eutelsat merged with OneWeb in 2022, which has satellites orbiting in LEO at 1,200 km.
So I suppose they also have access to that.
I don’t know much about this but I think these low earth orbit satellites bump into ozone molecules occasionally so their orbits will deteriorate after 5 years or so. That is to say, you need to replenish regularly.
You are right that low orbit satellites aren’t in a stable orbit and eventually fail in a matter of years. I think it very much depends on what the intended useage would be for a european constellation:
How much coverage do we want? Global or just the continent+ a bit more?
Would it just be for critical systems or are we also looking for economic independence?
What about bandwith and latency, how much do those matter?
All that would influence how many satellites are neccesarry and which orbits would be suitable. And also to what degree cost efficiency would play a role.
I admit I don’t know much about orbital physics, but I don’t see how you can have consistent coverage of Europe 24 hours per day and low pings comparable to Starlink without also covering the entire globe. Geosynchronous or sun synchronous orbits require a minimum ping of 240ms, round trip.
If you want to be effective, you need to drift south as much as you drift north to get adequate coverage - still a circular orbit, just tilted off the equator. This causes a real problem, because northern Europe is far enough north that you have to pretty much cover the whole world, anyway. Also, the more you move from the equator, the more bands of satellites you will need to have coverage at all times. The other part in the Starlink system is the requirement for some number of base stations to connect to the internet backbones. Further iterations are reducing this need, but it will never be 0.
What this means is, it would be cheaper for Brazil or the Middle East to have local satellite internet than it is for Europe, China, or Australia. In fact, if Europe had a low-orbit satellite internet offering, it would be more cost effective to sell it worldwide because they would be close to that just covering their own needs. Which is also the position Starlink has chosen to be in.
Ooh, that’s a fascinating point, thank you
I suppose it could be done launching those satellites from French Guyana still