Orbital Decay Predictor

What It Does

The Orbital Decay Predictor estimates how long a spacecraft will remain in orbit before reentering the atmosphere. Input your orbit altitude, spacecraft mass, cross-sectional area, drag coefficient, and solar activity level. The predictor computes the ballistic coefficient and propagates the orbit forward, outputting altitude vs time, estimated reentry date, and compliance with the 25-year deorbit guideline.

Key Features

• Atmospheric density models with solar activity (F10.7) input
• Altitude vs time propagation with reentry date prediction
• 25-year and 5-year compliance check with pass/fail indicator
• Ballistic coefficient sensitivity analysis

Why It Matters

Every LEO spacecraft must demonstrate compliance with orbital debris mitigation guidelines — typically the 25-year deorbit rule (and increasingly the 5-year FCC rule). If your spacecraft cannot deorbit naturally within the required timeframe, you need a propulsive deorbit capability, which adds mass, cost, and complexity. Running this analysis early prevents discovering compliance problems at the FCC licensing stage.

Related Calculators