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SAGE On-Board Schedule

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🚧 This document is still being actively worked on and is subject to change. 🚧

Responsible
  • Severin Richner
Last Updated10/12/2025, 12:48:54 PM
Last AuthorKai Berszin

The SAGE On-Board Scheduler is actively being developed as part of the Flight-Dynamics Pipeline.

Scope and Limitations​

How tasks can be scheduled on the satellite depends on the requirements and limitations of it's subsystems as well as many other factors, such as the current position in orbit, connectivity to the ground-station, etc.

In this section we lay out these different limitions.

Limitations concerning the EPS​

  • The EPS Design Report 2024/03/09 contains useful information all about how power is handled on board the satellite and specifically mentions:
    • an overall peak power limit under 2.2.1
    • estimated power output per solar pannel under 2.3
    • power budget estimates for the different operating modes (Commissioning, Downlinking, Science, Emergency) on page 4.2 and in more detail in the Appendix
    • various power simulations to estimate charge/discharge and even orbit determination and overflight windows under 4.3/4.4
  • The power matrix details the expected power consumption (avg & peak) per subsystem (CubeADCS, Magnetorquer, Reactionwheels, Earth Sensor, Magnetometer, Sun Sensor, SatNogs, UHF Deployment, Amateur Radio, Power Board, Solar Panels, Main Board, Sensor Board, GNSS, Payload, Eclipse Mode) and mode of operation (Commissioning, Nominal, Experiment, Safe).
  • An overview of the hardware and their characteristics can be found under EPS and the factsheets of these components are located in 02_components.

Limitations concerning the ADCS​

  • The ADCS Analysis Report 2024/03/10 contains:
    • Modes of Operation and their transitions (which sets limitations on how fast we can switch between certain tasks) in 1.2 and 1.3
    • The satellite controllers response times will impact the task switching time. The controllers are described under 6. Same goes for the actuator control described under 7.
    • For the GNSS system, estimates exist for how much power consumption and data volume can be expected for a certain GNSS message, as refered to in under 8.
  • Documentation on Ground-Pointing and Sun-Pointing will contain simulation results and power consumption estimations relevant for scheduling tasks.

Digital Twin Usage​

The SAGE Digital Twin is used as the main validation tool for checking the viability of schedules. The Digital Twin already implements many of the above mentioned limitations. However, some limitations and systems were out-of-scope for the thesis at the time (June 2024).