What is deorbit?
Deorbit is the process of removing a spacecraft from its operational orbit and causing it to eventually re-enter Earth's atmosphere. For LEO satellites, re-entry typically results in the satellite burning up due to aerodynamic heating — though dense components (titanium tanks, large structures) can survive to impact the ground or ocean. For GEO satellites, re-entry from 35,786 km requires an enormous delta-v; instead, GEO satellites are raised to a 'graveyard orbit' approximately 300 km above GEO at end of life.
Controlled vs. uncontrolled deorbit
Controlled deorbit: The satellite performs a retrograde propulsive manoeuvre to lower its perigee into the atmosphere, controlling the ground track of the debris landing zone to avoid populated areas. Controlled deorbit allows operators to target open ocean splash zones (the South Pacific Ocean Point Nemo is the primary target for large LEO objects). Uncontrolled deorbit: After propellant exhaustion, atmospheric drag gradually decays the orbit over months to centuries depending on altitude. At 550 km, natural decay takes approximately 5 years; at 1,200 km, it takes over 100 years without active disposal.
Regulatory requirements
The FCC's 2022 Space Debris Mitigation rules require LEO satellites to deorbit within 5 years of mission end — down from the previous 25-year guideline. Similar 5-year requirements are being adopted by European regulators and recommended by the IADC. Failure to comply is grounds for licence revocation and regulatory sanctions. Satellites must reserve sufficient propellant throughout their lifetime to execute the deorbit burn — a design requirement that reduces the propellant available for revenue-generating station-keeping and impacts satellite lifetime planning.