This note was part of the following paper: Cybersecurity Protections for Spacecraft: A Threat Based Approach
As an expansion to the earlier defense-in-depth graphic, figure below provides a breakout of spacecraft security principles that can aid in resilience and cyber protections. For the spacecraft, most security is geared around cryptography on the command link, Transmission Security (TRANSEC), and some Telecommunications Electronics Materials Protected from Emanating Spurious Transmissions (TEMPEST) controls. The items highlighted in red are where cyber gaps most likely reside:
