Orbital Debris Collision Risk Calculator
Estimate the collision risk for a satellite in low Earth orbit based on altitude, cross-sectional area, and mission duration.
Formulas Used
The collision risk index estimates the likelihood of a satellite colliding with orbital debris, expressed as a percentage score (0–100%).
- Altitude Factor:
\[ \text{AltitudeFactor} = e^{-\frac{|\text{altitude} – 800|}{200}} \]
Models debris density, peaking at 800 km where LEO debris is most concentrated.
- Area Factor:
\[ \text{AreaFactor} = \min\left(1, \frac{\text{area}}{10}\right) \]
Scales collision probability based on cross-sectional area, normalized to 10 m².
- Duration Factor:
\[ \text{DurationFactor} = \min\left(1, \frac{\text{duration}}{5}\right) \]
Scales risk with mission duration, normalized to 5 years.
- Collision Risk Index:
\[ \text{CollisionRiskIndex} = (\text{AltitudeFactor} \times \text{AreaFactor} \times \text{DurationFactor} \times 100)\% \]
Combines factors to estimate risk, capped at 100%. Higher scores indicate higher collision risk.
Example Calculations
Example 1: Small Satellite in LEO
Inputs: Altitude = 800 km, Area = 10 m², Duration = 5 years
Calculations:
- Altitude Factor: \[ e^{-\frac{|800 – 800|}{200}} = 1 \]
- Area Factor: \[ \min\left(1, \frac{10}{10}\right) = 1 \]
- Duration Factor: \[ \min\left(1, \frac{5}{5}\right) = 1 \]
- Collision Risk Index: \[ (1 \times 1 \times 1 \times 100) = 100\% \]
Result: Collision Risk Index: 100% (maximum risk at peak debris altitude)
Example 2: CubeSat in Lower LEO
Inputs: Altitude = 400 km, Area = 1 m², Duration = 2 years
Calculations:
- Altitude Factor: \[ e^{-\frac{|400 – 800|}{200}} \approx 0.135 \]
- Area Factor: \[ \min\left(1, \frac{1}{10}\right) = 0.1 \]
- Duration Factor: \[ \min\left(1, \frac{2}{5}\right) = 0.4 \]
- Collision Risk Index: \[ (0.135 \times 0.1 \times 0.4 \times 100) \approx 0.54\% \]
Result: Collision Risk Index: 0.54% (low risk due to small size and short duration)
Example 3: Large Satellite in Higher LEO
Inputs: Altitude = 1200 km, Area = 20 m², Duration = 10 years
Calculations:
- Altitude Factor: \[ e^{-\frac{|1200 – 800|}{200}} \approx 0.135 \]
- Area Factor: \[ \min\left(1, \frac{20}{10}\right) = 1 \]
- Duration Factor: \[ \min\left(1, \frac{10}{5}\right) = 1 \]
- Collision Risk Index: \[ (0.135 \times 1 \times 1 \times 100) \approx 13.53\% \]
Result: Collision Risk Index: 13.53% (moderate risk due to large area and long duration)
How to Use the Calculator
Follow these steps to estimate the collision risk for a satellite:
- Enter Altitude: Input the satellite’s altitude in kilometers (100–2000 km, typical for LEO).
- Enter Cross-Sectional Area: Input the satellite’s cross-sectional area in square meters (e.g., 10 for a typical satellite).
- Enter Mission Duration: Input the mission duration in years (e.g., 5 for a standard mission).
- Calculate: Click “Calculate Collision Risk” to see the result.
- Interpret Result: The Collision Risk Index (0–100%) indicates the likelihood of a debris collision. Higher scores mean higher risk. If you see “Please fill in all fields,” ensure all inputs are provided.
- Share or Embed: Use the share buttons to post results on social media, copy the result, or get an embed code for the calculator.
Note: This is a simplified model. Actual collision risk depends on factors like debris size, velocity, and mitigation measures.