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Technical

Conjunction Assessment

The process of evaluating potential close approaches between space objects to determine collision risk and inform avoidance decisions.

Conjunction assessment is a critical space safety process that identifies and evaluates close approaches between space objects, enabling operators to take collision avoidance action when necessary.

Process Steps

  1. Screening: Identify potential close approaches from catalog data
  1. Refinement: Improve accuracy with additional observations
  1. Risk Assessment: Calculate collision probability
  1. Decision: Determine if avoidance maneuver is needed
  1. Coordination: Communicate with other operators if applicable
  1. Execution: Perform maneuver if required
  1. Verification: Confirm post-maneuver safety

Key Metrics

  • Time of Closest Approach (TCA)
  • Miss distance
  • Collision probability (Pc)
  • Mahalanobis distance

Thresholds Typical action thresholds:

  • Pc > 10⁻⁴: Maneuver recommended
  • Pc > 10⁻³: Maneuver strongly advised
  • Miss distance < 1 km (LEO): Close monitoring

Regulatory Requirements Under the EU Space Act, operators must:

  • Participate in conjunction data sharing
  • Respond to conjunction warnings
  • Report avoidance maneuvers
  • Maintain maneuver capability