Autonomous Position estimation is a key enabling capability for all kinds of spacecraft. Existing methods rely mostly on telemetry from the ground (e.g. RADAR, or other form of active tracking) or global navigation system (e.g. GPS). Long term exploration missions, such as human mission to Mars or asteroids, including asteroid mining, will require the ability to perform navigation autonomously, without assistance from Earth (which also involves significant delays due to the immense distances of space travel). This additional robustness is a must for NASA human exploration missions. Other classes of space vehicles would also benefit from having this capability because of the additional robustness granted to space-vehicle operations. Increased vehicle autonomy is a key requirement for the NASA technology development roadmap. The proposed technology favors dual-use of existing assets, the star trackers, and therefore does not burden the system engineers with additional weight, size, and significant power requirements, leaving more options for experiment and support payloads. In addition, the increased accuracy of the autonomous position estimation enables the vehicle to monitor and adjust its own orbit in the critical phases of orbit entry or aero-braking, when the spacecraft is obscured from Earth or the delay in communication proves critical.
The problem of autonomous position estimation is general to all spacecraft manufacturers and therefore is also of great commercial interest also outside NASA. In the future, private entities will also be involved in long distance missions; asteroid mining, for instance, has been proposed as a potentially important application of interplanetary travel. In this case, commercial entities will have the same autonomy requirements that NASA exploration missions already face. In addition, there is great interest in the Department of Defense (e.g. Air Force Space Command), to increase the resilience of their space assets to a deliberate attack to the GPS satellites by a hostile power. Increased autonomy of DOD space assets requires accurate position estimation. The proposed method could be extended to satellites orbiting Earth in GEO, thus providing important redundancy in position estimation in a GPS-denied environment.