## 3 Model-Based System Engineering for Preliminary Design
### Integration of System Requirements within the Capella System Model
#### 3.3.1 Subsystem Design Integration  
1. Power Subsystem (EPS):  
* Continuous availability of power.
* Efficient solar power generation and distribution.
* Resistance to space environmental conditions.
* Logical and Physical Design:
* Logical Functions: power generation, storage, and distribution.
* Physical Components: solar panels, batteries, and power management units (PMUs).
* Traceability: the requirements for continuous power were linked to specific physical components, such as solar panels and batteries, ensuring direct alignment from requirement to implementation.
2. On-Board Computer (OBC): * Requirements: * Data processing, command execution, and system monitoring. * High reliability and fault tolerance. * Logical and Physical Design: * Logical Functions: data processing, command handling, and system health monitoring. * Physical Components: locally manufactured OBC capable of performing the identified logical functions. * Traceability: the requirements for data processing and command execution were linked to the physical OBC component. 3. Attitude Determination and Control System (ADCS): * Requirements: * Precise control and stabilization of orientation. * Fine-tuning capability and automatic correction. * Logical and Physical Design: * Logical Functions: attitude sensing, control algorithms, and actuation. * Physical Components: reaction wheel, fine-sun sensor, and magnetorquers. * Traceability: the attitude control requirements were linked to the ADCS components, ensuring each logical function was reflected in the physical design. 4. Communication Subsystem (COMMS): * Requirements: * Reliable communication with ground stations. * Capability for long-distance data transmission and reception. * Logical and Physical Design: * Logical Functions: signal transmission, reception, and encoding/decoding. * Physical Components: antennas, transceivers, and modems. * Traceability: the reliability requirements for communication were traced to specific components designed to handle data transmission and reception. 5. Thermal Control Subsystem: * Requirements: * Maintenance of operational temperatures within safe limits. * Protection against extreme space temperatures. * Logical and Physical Design: * Logical Functions: heat dissipation and thermal insulation. * Physical Components: radiators, thermal blankets, and heaters. * Traceability: the thermal control requirements were linked to the physical components, ensuring effective thermal management. 6. Payload Subsystems: * MiniPIX TPX3 SPACE Sensor: * Requirements: * Capability for particle detection and scientific data acquisition. * Low power consumption and reduced weight. * Logical and Physical Design: * Logical Functions: particle detection, data acquisition, and analysis. * Physical Components: MiniPIX TPX3 SPACE sensor and associated electronics.  
Traceability: the scientific data collection requirements were linked to the MiniPIX sensor, ensuring alignment with mission objectives.
* IoT Payload:
* Enable IoT connectivity in remote areas.
* Support for educational and social impact initiatives.
* Logical and Physical Design:
* Logical Functions: IoT data transmission, environmental monitoring, and connectivity.
* Physical Components: IoT transceivers, sensors, and supporting electronics.
* Traceability: the requirements for IoT connectivity and educational outreach were linked to the IoT payload components, ensuring they met the mission's social and educational objectives.