> ## Documentation Index > Fetch the complete documentation index at: https://docs.rotastellar.com/llms.txt > Use this file to discover all available pages before exploring further. # Conjunction Analysis > Collision probability and avoidance recommendations # Conjunction Analysis Analyze potential collisions between space objects and receive recommendations for avoidance maneuvers. **Status:** Early Access — [Request API key](https://rotastellar.com/developers) ## Overview Conjunction analysis evaluates: * **Time of Closest Approach (TCA)** — When objects will be nearest * **Miss Distance** — Predicted separation at TCA * **Collision Probability** — Statistical likelihood of collision * **Avoidance Options** — Maneuver recommendations if needed ## Quick Start ```python Python theme={null} from rotastellar import RotaStellarClient client = RotaStellarClient(api_key="rs_...") # Get conjunctions for a satellite conjunctions = client.list_conjunctions( satellite_id="STARLINK-1234", threshold_km=5.0, limit=10 ) for conj in conjunctions: print(f"TCA: {conj['tca']}") print(f"Miss distance: {conj['miss_distance_km']} km") print(f"Probability: {conj['collision_probability']:.2e}") print() ``` ```typescript Node.js theme={null} import { RotaStellarClient } from '@rotastellar/sdk'; const client = new RotaStellarClient({ apiKey: 'rs_...' }); const conjunctions = await client.listConjunctions({ satelliteId: 'STARLINK-1234', thresholdKm: 5.0, limit: 10 }); for (const conj of conjunctions) { console.log(`TCA: ${conj.tca}`); console.log(`Miss: ${conj.miss_distance_km} km`); console.log(`Probability: ${conj.collision_probability}`); } ``` ```rust Rust theme={null} // Rust SDK provides types only (HTTP client coming soon) // Use Python or Node.js SDK for full API access // See /sdks/rust for available types ``` ```bash cURL theme={null} curl "https://api.rotastellar.com/v1/conjunctions?satellite=STARLINK-1234&threshold_km=5&days_ahead=7" \ -H "Authorization: Bearer rs_your_api_key" ``` ## Get Conjunctions ``` GET /v1/conjunctions ``` Primary satellite (NORAD ID or name) Maximum miss distance to report (km) Prediction window (1-14 days) Minimum collision probability to report (e.g., 1e-6) ### Response ```json theme={null} { "conjunctions": [ { "id": "conj_abc123", "tca": "2026-01-23T14:32:15Z", "primary": { "id": "12345", "name": "STARLINK-1234", "operator": "SpaceX" }, "secondary": { "id": "45678", "name": "COSMOS 2251 DEB", "type": "DEBRIS" }, "miss_km": 0.45, "probability": 2.3e-5, "risk_level": "HIGH", "relative_velocity_km_s": 14.2, "geometry": { "radial_km": 0.12, "in_track_km": 0.38, "cross_track_km": 0.18 }, "covariance_available": true, "data_quality": "GOOD" } ], "screening_window": { "start": "2026-01-21T00:00:00Z", "end": "2026-01-28T00:00:00Z" }, "total_count": 12 } ``` ## Risk Levels | Level | Probability Range | Recommended Action | | ---------- | ----------------- | ------------------------- | | `LOW` | \< 1e-5 | Monitor | | `MEDIUM` | 1e-5 to 1e-4 | Review, consider maneuver | | `HIGH` | 1e-4 to 1e-3 | Plan maneuver | | `CRITICAL` | > 1e-3 | Execute maneuver | ## Conjunction Details Get detailed information about a specific conjunction: ``` GET /v1/conjunctions/{conjunction_id} ``` ```python Python theme={null} # Get conjunction details via REST API import requests response = requests.get( "https://api.rotastellar.com/v1/conjunctions/conj_abc123", headers={"Authorization": "Bearer rs_your_api_key"} ) conj = response.json() print(f"TCA: {conj['tca']}") print(f"Miss: {conj['miss_km']} km") print(f"Radial: {conj['geometry']['radial_km']} km") print(f"In-track: {conj['geometry']['in_track_km']} km") print(f"Cross-track: {conj['geometry']['cross_track_km']} km") # Check avoidance options if conj['risk_level'] in ["HIGH", "CRITICAL"]: for opt in conj.get('avoidance_options', []): print(f"Maneuver: {opt['delta_v_m_s']} m/s at {opt['burn_time']}") print(f"New miss distance: {opt['resulting_miss_km']} km") ``` ```bash cURL theme={null} curl https://api.rotastellar.com/v1/conjunctions/conj_abc123 \ -H "Authorization: Bearer rs_your_api_key" ``` ### Detailed Response ```json theme={null} { "id": "conj_abc123", "tca": "2026-01-23T14:32:15Z", "miss_km": 0.45, "probability": 2.3e-5, "risk_level": "HIGH", "primary": { "id": "12345", "name": "STARLINK-1234", "position_at_tca": { "lat": 45.2, "lon": -122.5, "altitude_km": 550 } }, "secondary": { "id": "45678", "name": "COSMOS 2251 DEB", "position_at_tca": { "lat": 45.3, "lon": -122.4, "altitude_km": 550.3 } }, "geometry": { "radial_km": 0.12, "in_track_km": 0.38, "cross_track_km": 0.18 }, "covariance": { "primary_sigma_r_km": 0.05, "primary_sigma_t_km": 0.15, "primary_sigma_n_km": 0.02, "secondary_sigma_r_km": 0.50, "secondary_sigma_t_km": 1.50, "secondary_sigma_n_km": 0.30 }, "avoidance_options": [ { "type": "in_track", "delta_v_m_s": 0.5, "burn_time": "2026-01-23T10:00:00Z", "resulting_miss_km": 5.2, "fuel_cost_kg": 0.02 }, { "type": "radial", "delta_v_m_s": 0.3, "burn_time": "2026-01-23T08:00:00Z", "resulting_miss_km": 3.8, "fuel_cost_kg": 0.012 } ], "updates": [ { "timestamp": "2026-01-21T12:00:00Z", "miss_km": 0.52, "probability": 1.8e-5 }, { "timestamp": "2026-01-22T00:00:00Z", "miss_km": 0.45, "probability": 2.3e-5 } ] } ``` ## Monitoring Conjunctions Set up continuous monitoring for your satellites: ```python Python theme={null} # Create a watch for conjunction alerts via REST API import requests response = requests.post( "https://api.rotastellar.com/v1/conjunctions/watch", headers={ "Authorization": "Bearer rs_your_api_key", "Content-Type": "application/json" }, json={ "satellites": ["SAT-001", "SAT-002", "SAT-003"], "threshold_km": 5.0, "min_probability": 1e-6, "webhook_url": "https://your-app.com/conjunction-alerts" } ) watch = response.json() print(f"Watch ID: {watch['id']}") print(f"Status: {watch['status']}") ``` ```bash cURL theme={null} curl -X POST https://api.rotastellar.com/v1/conjunctions/watch \ -H "Authorization: Bearer rs_your_api_key" \ -H "Content-Type: application/json" \ -d '{ "satellites": ["SAT-001", "SAT-002", "SAT-003"], "threshold_km": 5.0, "min_probability": 1e-6, "webhook_url": "https://your-app.com/conjunction-alerts" }' ``` ## Fleet Screening Screen multiple satellites at once: ```python theme={null} # Screen entire constellation satellites = ["SAT-001", "SAT-002", "SAT-003", "SAT-004"] results = {} for sat_id in satellites: conjunctions = client.list_conjunctions( satellite_id=sat_id, threshold_km=5.0, limit=50 ) results[sat_id] = conjunctions for sat_id, conjunctions in results.items(): print(f"\n{sat_id}: {len(conjunctions)} conjunctions") for conj in conjunctions: print(f" - Miss: {conj['miss_distance_km']}km") ``` ## Next Steps Detect anomalies and maneuvers Set up real-time alerts