Patch Management of Satellite Flight Software

The satellite flight software is the software that enables the satellite to perform predefined tasks during its lifecycle and controls vital functions related to the satellite. For a satellite to perform its mission successfully, it must have the ability to correct errors found in its software while it is in orbit, with minimal disruption to mission operations. The solving of errors in the software is only possible via updates and when considering a satellite in orbit, the most practical method of updates is through patches. By means of patches, it is possible to add a new feature to the satellite flight software, to change an existing feature in the software or to fix the errors found in the software. However, considering the space domain, while patching the satellite flight software, there are constraints such as availability of the system, telemetry/telecommand bandwidth and the available memory dedicated to be used for patching. In line with the relevant constraints, solutions for minimizing the patch data size and finding different patching approaches must be considered. The aim of this study is to provide information about patching techniques and approaches considered to modify the satellite flight software through patches. Two approaches where the flight software or the bootloader is used for the patching process along with two different patch data generation techniques will be analyzed.