Behzad Koosha, SpaceLink; Jim Schwenke, SpaceLink; Rob Singh, SpaceLink; David Nemeth, SpaceLink
Keywords: Optical Satellite Communications, Scheduling, Space Situational Awareness (SSA), Hybrid Architecture
Abstract:
Abstract – centralized scheduler interface for communication link between SpaceLink’s relay satellites and LEO assets
B. Koosha , R. Singh, D. Nemeth, J. Schwenke
SpaceLink can augment the hybrid architecture, between multi-orbit constellations, including those supporting Space Situational Awareness (SSA). SpaceLink is building its own commercial transport layer to provide persistent connectivity to assets in Low Earth Orbit (LEO) and deliver data and communications to and from space in near-real-time and with unprecedented security. Real-time coordination of multi-vendor satellite constellations and their dynamic ephemeris, system constraints, and schedules is an incredible challenge. These include orbital ephemeris, relative attitude, optical terminal range of motion, terminal and SV slew rates, SV jitter, and service level agreements that factor into link acquisition times. SpaceLink’s planning and scheduling algorithm can manage these challenges. The proposed solution conducts all the coordination and is easily integrated within the satellite command and control operations center to automatically send tasking requests for communication between different satellite constellations.
SpaceLink can augment the hybrid architecture capabilities to coordinate the optical heads between multi orbit constellation satellites. SpaceLink optical terminals are compatible with SDA’s Tranche 1 standards, so it can also provide a redundant path for the SDA’s Transport Layer to provide path plan options in support of scenarios in which there is limited availability of any space or ground assets. In a scenario where there are multiple end users, each client requests are queued and processed in the order they are received. The proposed algorithm provides the capability to define priorities based on organization, budgets, and system requirements in near real-time. In this case, client requests are placed into a priority queue, where higher priority client requests go to the front of the queue. Each client request results in changes to the schedule (adds/mods/deletes) and those changes are constantly broadcast back to clients.
The proposed algorithm has multiple ways to receive ephemeris and calculate visibilities for the specific vehicles. As we develop the algorithm, it ensures updated visibilities are always available based on the latest ephemeris/TLEs using machine learning techniques. SpaceLink’s four satellites are always in sight of spacecrafts above 350 km in altitude. The initial constellation will be operational in mid-2024. Subsequent constellations will include inclined orbits that will allow full visibility down to the Earth.
This paper represents a study of the centralized scheduler interface used for the communication link between SpaceLink relay satellites and the hybrid constellation of satellites. We will provide information on the scheduling interface which sends tasking information to the SpaceLink C2 segment via an internal communication protocol to command a SpaceLink MEO satellite to establish and command an optical head to point to a visible LEO satellite.
Date of Conference: September 27-20, 2022
Track: SSA/SDA