This is hardly a 'first'. ESA felt their satellite was being obstructed by SpaceX who moved into the space much later and didn't act responsibly as they should have. So ESA decided to send out a press release.
Basically ESA nicely asked SpaceX to maneuver their sat and shorten its lifetime - they don't have a legal basis or enforcement mechanism anyway. SpaceX pretended not to hear until it was too late and ESA went ahead with their contingency plan of burning their own sat's fuel and lifetime instead.
a. They did an altitude increase. There's no real gains from an earlier burn that one might get when doing something like a hohmann transfer.
b. Half an orbit before out means more/better telemetry to work with.
c. They are from a quick google, well within the range where atmospheric drag plays a role, and you need to do station keeping. leaving it this late means you don't "waste" fuel from drag.
Admittedly, my only credentials for this are a few thousand hours in KSP and reading around the subject. Anyone with a proper degree on this is welcome to correct me.
If that wasn't the case, they could raise or lower the altitude slightly several orbits before the "event" causing them to arrive at the intersection point earlier or later. For a desired time delta, the sooner your perform your altitude change the smaller the changed required.
I would.
https://en.wikipedia.org/wiki/Space_Liability_Convention
> States (countries) bear international responsibility for all space objects that are launched within their territory. This means that regardless of who launches the space object, if it was launched from State A's territory, or from State A's facility, or if State A caused the launch to happen, then State A is fully liable for damages that result from that space object.
ESA’s take on the matter is that it was annoying that they couldn’t contact SpaceX, and that relying on email and phone calls between humans is not going to work when there are tens of thousands of satellites in orbit.
The Twitter thread which started this was about ESA’s plans to automate their entire collision detection and avoidance process, and a call for an industry consensus on processes and protocols for communicating facts and intentions between satellite operators, and a set of rules and policies for managing space traffic, similar to what is done for international air traffic today.