They don't need to keep exact position; they just need to know their relative distance offsets from Earth to synchronize pulses. They can do some work to keep

They don't need to keep exact position; they just need to know their relative distance offsets from Earth to synchronize pulses. They can do some work to keep station; the idea is that by adjusting attitude, they can adjust the magnitude and direction of their drag vector. https://arxiv.org/abs/2309.07061 https://arxiv.org/abs/2309.07061 It's absolutely infeasible with current technology, but it doesn't look like it's total unobtanium.