Objective: The objective of the activity is to develop autonomous collision avoidance mechanisms including warning management, manoeuvre decision taking, design, planning and execution for future NGSO constellations with very large number of spacecraft and GEO satellites with electrical orbit raising.
Algorithms and functions will be implemented and demonstrated on a software test bed that will include those space and ground segment elements involved in collision avoidance operations (interface with space situational awareness entity, ground control centre, ground stations, spacecraft).
Targeted Improvements: Enabling key technology developments for autonomous collision avoidance operations not available today.
Enabling technology developments to reduce the operational load and increase the safety of operations to preserve the space environment.
Description: The presence of satellites and space debris in lowEarth orbit requires operators of spacecraft flying in that region to cater for collision avoidance strategies in their operations.The complexity of collision avoidance is significant as it must cover from the interaction with the entity(ies) providing space situational awareness (SSA) to the triggering and monitoring of collision avoidance manoeuvres. In the process a number of crucial aspects need to be addressed: continuous screening and monitoring of conjunction warnings and assessment of their associated risk, closemonitoring of high risk conjunctions in cooperation with the SSA entities, establishing criteria and decision making procedures fortriggering collision avoidance manoeuvres, designing appropriate manoeuvres for each conjunction and verifying their safety with the SSA entities. All these become even more critical for spacecraft with electric propulsion as they have significantly longer manoeuvre times requiring early triggering with higher uncertainty about the conjunction.
Besides the complexity, the operational load associated to collision avoidance in LEO may also be significant. The large population of satellites and space debris in this region may cause a substantial number of warnings, which render impractical and error-prone a human-based approach. The problem is further exacerbated if the operator is in charge of a large fleet of satellites. In this case automation is a must. This is key for the safe operation of NGSO constellations and the sustainable use of Space.
This activity will develop mechanisms to allow autonomous collision avoidance operations to the greatest extent possible by automating all the processes and procedures involved. The automation will span from conjunction warning screening (including risk assessment) to collision avoidance manoeuvres (automated decision taking, design, safety assessment, planning and execution). It will determine what needs to be done on ground, what on board and coordination procedures with other space users. It will also propose data formats, interfaces and processes enabling the exchange between operators and SSA data providers. The resulting collision avoidance strategy will be implemented and demonstrated in a software test bed. Special attention will be paid to NGSO spacecraft with electric propulsion. The activity will also consider GEO satellites doing electrical orbit raising.