Once a CubeSat launches, you cannot physically access it again. Any software fixes must be sent remotely via OTA updates.

Release Process

Step 1: Developer pushes code

git commit
git push origin feature_branch

Step 2: Merge to main

Pull request → review → merge into main

Step 3: CI/CD builds firmware

compile firmware
run tests
build binary
assign version number

Step 4: Release artifact & store in interfaces folder

firmware_v2025_03_01.bin

Step 5: OTA deployment

Ground station sends firmware:

uplink firmware
satellite verifies version
installs update

Firmware Versioning Strategies

• Semantic Versioning (SemVer) is structured as MAJOR.MINOR.PATCH
  • Used by NASA (i.e. POWER project%20daily%20radiation%20data.))
• Data-based Versioning
  • Used by Ubuntu
• Bit Packed Versioning: custom binary version code format stored in 1 byte YYMMMMRR
  • Used in IoT devices, embedded firmware and satellites

CubeSat / Satellite Software Resources

• NASA Core Flight System (cFS)