They are perfect markers only as long as you can see them. Clouds and fog are your enemies here
The future is more likely to be quantum accelerometers and quantum gyroscopes, as they have no “external dependency”.
Encrypted positioning information from low-orbit satellites is another option.
It also is not really applicable when you are on a balistic course at *very* high altitude, course correction has to happen early in these case given the reentry speed/constraints.