Comparison between Different Re-Entry Technologies for Debris Mitigation in LEO

The population of satellites in Low Earth Orbit is predicted to growth exponentially the next decade due proliferation small-sat constellations. Consequently, probability collision expected increase dramatically, possibly leading a potential Kessler syndrome situation. It therefore necessary strengthen all technologies required for avoidance and end-of-life disposal new satellites, together with active debris removal current future dead satellites. Both situations require lowering altitude satellite up re-entry. In this paper several de-orbiting are evaluated: natural decay, chemical propulsion (solid liquid), electric propulsion, drag sail, electrodynamic tether, combinations previous ones. comparison considers initial altitude, system mass, time, during descent, reliability, technological limits. Differences between self-disposal taken into account. Moreover, different types re-entry, controlled vs. non-controlled, expendable reusable system, demisable non-demisable also discussed. Finally, possibility operate Very Orbits compensation passive re-entry at end life investigated.