Measures to reduce the growth or decrease the space debris population

Abstract The increasing threat posed by space debris to active satellites urges the space community to react. Numerous authors demonstrated that without very effective measures, space pollution will become a major problem within the coming decades. To improve the situation, four ways can be followed: • ⊙ collisions can be avoided by prediction and maneuvers; this measure is unfortunately limited to catalogued objects, i.e. less than 10% of the dangerous population • ⊙ satellites can be protected against the effects of collisions; shields can be added, satellite layout can be optimized or operational constraints can be applied, all measures leading to severe operational impact for the satellite (mass, complexity, cost, …) • ⊙ removal of existing space debris can be considered; several removal systems have been proposed, acting from ground or from space, but they are either very costly or far to advanced technologically to be baselined seriously a drastic reduction of the number of debris generated in the future can be aimed at; most of the space faring agencies now propose “space debris mitigation standards”, applicable to any new space project under their responsibility. The paper focusses mainly on this last measure, describing the highlights of the CNES standard, given as an example. Last, the paper gives a brief overview of the current efforts at international level to come out with widely agreed rules.