def pre_launch_system_verification():
    """
    Artemis II Pre-Launch System Verification Implementation
    Task 2: Detailed checklist for spacecraft systems verification
    Author: starlight-autonomous-agent
    Version: 2.0
    """
    
    import json, datetime, math
    
    verification_systems = {
        "propulsion": {
            "systems": [
                "SLS Core Stage Engines",
                "Upper Stage Engine", 
                "Orion Service Module Propulsion",
                "Reaction Control System",
                "Launch Abort System Motor"
            ],
            "checks": [
                "Engine gimbal test",
                "Propellant leak detection",
                "Thrust chamber pressure verification",
                "Valve operation test",
                "Fuel temperature monitoring"
            ],
            "personnel": ["Propulsion Engineer", "Systems Engineer", "Safety Officer"],
            "pass_fail_criteria": {
                "engine_gimbal_range": "±10 degrees operational",
                "leak_detection": "Zero detectable leaks",
                "pressure_tolerance": "±5% of nominal",
                "valve_response": "<2 seconds",
                "fuel_temp": "Within specified range"
            }
        },
        
        "life_support": {
            "systems": [
                "Environmental Control System",
                "Oxygen Generation System",
                "CO2 Scrubbing System",
                "Water Recovery System",
                "Fire Detection/Suppression"
            ],
            "checks": [
                "Cabin pressure test",
                "Oxygen concentration verification",
                "CO2 removal efficiency test",
                "Water purification cycle test",
                "Fire sensor calibration"
            ],
            "personnel": ["Life Support Engineer", "Medical Officer", "Systems Technician"],
            "pass_fail_criteria": {
                "cabin_pressure": "14.7 ± 0.2 psi",
                "oxygen_level": "21-23% concentration",
                "co2_removal": ">95% efficiency",
                "water_purity": "<10 ppm contaminants",
                "fire_sensor_response": "<1 second detection"
            }
        },
        
        "navigation_communication": {
            "systems": [
                "Primary Navigation Computer",
                "Backup Navigation System", 
                "Deep Space Network Interface",
                "S-Band Communication",
                "Ku-Band Communication"
            ],
            "checks": [
                "GPS constellation lock",
                "Star tracker calibration",
                "Communication link test",
                "Data transmission verification",
                "Antenna deployment test"
            ],
            "personnel": ["Navigation Engineer", "Communication Specialist", "Ground Controller"],
            "pass_fail_criteria": {
                "gps_lock": "4+ satellites locked",
                "star_tracker": "3+ stars identified",
                "comm_link": "BER < 10^-6",
                "data_rate": ">1 Mbps downlink",
                "antenna": "Full deployment confirmed"
            }
        },
        
        "safety_mechanisms": {
            "systems": [
                "Launch Abort System",
                "Emergency Egress System",
                "Range Safety System",
                "Collision Avoidance System",
                "Radiation Monitoring"
            ],
            "checks": [
                "Abort motor readiness",
                "Egress pathway clear",
                "Range safety command test",
                "Debris field analysis",
                "Radiation sensor calibration"
            ],
            "personnel": ["Safety Officer", "Range Safety Controller", "Medical Team"],
            "pass_fail_criteria": {
                "abort_response": "<1 second activation",
                "egress_time": "<2 minutes to safe zone",
                "range_safety": "Command authority verified",
                "debris_clearance": "Safe trajectory maintained",
                "radiation_levels": "Below threshold limits"
            }
        }
    }
    
    def generate_verification_checklist(verification_systems):
        """Generate complete verification checklist"""
        checklist = {
            "mission": "Artemis II",
            "task": "Pre-Launch System Verification",
            "date": datetime.datetime.now().isoformat(),
            "systems_status": {}
        }
        
        for system, data in verification_systems.items():
            checklist["systems_status"][system] = {
                "status": "PENDING",
                "checks_completed": 0,
                "total_checks": len(data["checks"]),
                "personnel": data["personnel"],
                "critical_items": []
            }
        
        return checklist
    
    def calculate_verification_metrics(total_checks, passed_checks):
        """Calculate verification success metrics"""
        if total_checks == 0:
            return {"success_rate": 0, "status": "NO_CHECKS"}
        
        success_rate = (passed_checks / total_checks) * 100
        status = "PASS" if success_rate >= 95 else "FAIL" if success_rate < 80 else "REVIEW"
        
        return {
            "success_rate": round(success_rate, 2),
            "status": status,
            "checks_remaining": total_checks - passed_checks
        }
    
    checklist = generate_verification_checklist(verification_systems)
    total_system_checks = sum(len(data["checks"]) for data in verification_systems.values())
    
    return {
        "task_completed": True,
        "system_verification": checklist,
        "total_checks_required": total_system_checks,
        "verification_systems": verification_systems,
        "implementation_details": {
            "propulsion_checks": 5,
            "life_support_checks": 5, 
            "navigation_checks": 5,
            "safety_checks": 5,
            "total_personnel_required": 12
        },
        "verification_metrics": calculate_verification_metrics(total_system_checks, 0),
        "completion_time": datetime.datetime.now().isoformat()
    }

if __name__ == "__main__":
    import json
    result = pre_launch_system_verification()
    print(json.dumps(result, indent=2))