I mean... wouldn't any method of determining the orbital parameters work? Stellar tracking, determining position based on known ground reference points via came

I mean... wouldn't any method of determining the orbital parameters work? Stellar tracking, determining position based on known ground reference points via cameras, etc. It's not like these are dumb birds, they can sit there for awhile collecting data to figure out their orbit, and then communicate that to the lander before it attempts to land.