NujoudEarth! This is from Orion's Optical Navigation Camera on Flight Day (FD) 2! These cameras are being calibrated on this flight for future missions to be able to safely return the crew without any ground communication! 1/2
Optical Navigation works by measuring the Earth or Moon diameter and limb (sunlight/darkness interface) to calculate how far and where Orion is relative to the body. Typical state (position) navigation is calculated by the radiometrics of the ground DSN signals. 2/2
Dr. Fred Calef III@nujoud oh! Star tracking or feature tracking of surface features?
@mapperwocky neither, measuring size of Earth/Moon limb & terminator to calculate relative distance/position
@mapperwocky but Orion ALSO has star trackers that provide the attitude knowledge in both nominal and contingency situations
@nujoud oh wow! Hadn’t thought of doing that. I guess that makes it cloud independent. What error range does that give you?
@mapperwocky I don't know value and prob couldn't share publicly if I did, but it is good enough to meet our entry interface constraints which are pretty tight. And that must be supported navigating for multiple days/a week or more from the Moon. It's not as good as radiometrics (at least now) but is still very capable.