4.2 - Space Segment Systems Engineering
4.4.2 - Bus Element Systems Engineering
4.4.4 - Structures & Mechanisms Subsystem (SMS)
4.4.4.5 - Mechanisms & Deployables
4.4.4.7 - Ordnance/Pyrotechnics
4.4.5 - Electrical Power & Distribution Subsystem (EPDS)
4.4.6 - Thermal Control Subsystem (TCS)
4.4.7 - Attitude Control Subsystem (ACS)
4.4.8 - Propulsion Subsystem (PS)
4.4.9 - Telemetry Tracking & Command Subsystem (TT&C)
4.4.10 - Command & Data Handling Subsystem (C&DH)
4.4.11 - Fault Management Subsystem (FMS)
4.4.12 - Software Subsystem (SS)
4.5.2 - Payload Element Systems Engineering
4.6 - Space Vehicle Ground Support Equipment