1. UN/ITU regulates orbit slots/shells (really frequency assignments that effectively limits orbit slots), high decay V/LEO, as in ~500km was basically exhausted by starlink. Big reason PRC announced multiple 10-20k mega constellations a few years ago (without reusable for to put-up payload) was to sign up for next closes shell which is 500+. At those distances orbit decay is decades/centuries. So regulatorily, the fast decay orbit slots are legally mostly gone.

2. All mega constellations including starlink has layers from 500-1500km. Every 100km is like 0.3ms latency but trade off is cheaper station (longer life time) keeping and wider coverage per satellite, but cost more to get there.

Related to 1&2 is this is byproduct of UN/ITU regulations... they can open up more <500km slots, increase congestion, confliction and chance of recoverable Kessler... but that would mean SpaceX (read US military) would... have to share strategic orbits with PRC and whoever comes next.

E: extrapolate to future of cheap space launch, if multiple blocs or even countries want their own mega constellations, and no changes to regulations, then they would have to start occupying higher orbit shells (assuming they follow ITU). Also geometrically, the shell lowest/closest to earth has the least volume / capacity.

Starlink competitors don't have SpaceX rockets and will tend towards different kinds of solutions to compensate. It is indeed significantly worse (signal strength, beam overlap) to go up to higher LEO altitudes, but that's a tradeoff you might make if you're inconfident about your orbital launchers and want to minimize risk there. You would need fewer satellites for initial coverage—fewer launches.

China's Thousand Sails (Qianfan) is secretive but possibly targets 800 km shells; I'll just quote Mike Wall and Jonathan McDowell,

> "That number is growing all the time; SpaceX has already launched more than 50 dedicated Starlink missions this year, with many more on the docket. Elon Musk's company already has permission to deploy 12,000 Starlink spacecraft in LEO, and it has applied for approval for another 30,000 on top of that."

> "Qianfan won't be quite that big, but it's in the ballpark."

> ""The satellites are similar to the V1 Starlinks, with flat-panel morphology and a mass of 300 kg [660 pounds] each. This 'G60' constellation is planned to eventually have 14,000 satellites," astrophysicist and satellite tracker Jonathan McDowell, of the Harvard-Smithsonian Center for Astrophysics, posted on X shortly after today's Qianfan launch."

> "The Qianfan satellites will apparently orbit at an altitude of about 500 miles (800 kilometers), he added in another post. That's higher than the Starlink constellation, which orbits at about 340 miles (550 km)."

https://www.space.com/china-first-launch-internet-satellite-...