4. Reference Mission Development
   4.1. Mission Design - First Flight
   4.2. Spacecraft Design
      4.2.0. System Engineering Data
      4.2.1. TransLunar Transportation System
      4.2.2. Descent Stage
      4.2.3. Lunar Habitat
      4.2.4. Ascent Vehicle
      4.2.5. Surface Vehicles and Robots
      4.2.6. Launch Vehicles
   4.3. Systems Design
   4.4. Spacecraft Production
   4.5. Ground Support
   4.6. Flight Crew
   4.7. Mission Operations
   4.10. Design Requirements and Specifications