▁and ▁the ▁efforts ▁of ▁the ▁UN ▁C OP U OS ▁committee . ▁ ▁In ▁ 2 0 0 7 , ▁the ▁ISO ▁began ▁prepar ing ▁an ▁international ▁standard ▁for ▁space - de br is ▁mit ig ation . ▁ ▁By ▁ 2 0 1 0 , ▁ISO ▁had ▁published ▁" a ▁compreh ensive ▁set ▁of ▁space ▁system ▁engineering ▁standards ▁aim ed ▁at ▁mit ig ating ▁space ▁de br is . ▁[ with ▁primary ▁requirements ] ▁defined ▁in ▁the ▁top - level ▁standard , ▁ISO ▁ 2 4 1 1 3 ." ▁By ▁ 2 0 1 7 , ▁the ▁standards ▁were ▁nearly ▁complete . ▁However , ▁these ▁standards ▁are ▁not ▁binding ▁on ▁any ▁party ▁by ▁ISO ▁or ▁any ▁international ▁juris diction . ▁They ▁are ▁simply ▁available ▁for ▁use ▁in ▁any ▁of ▁a ▁variety ▁of ▁volunt ary ▁ways . ▁They ▁" can ▁be ▁adopted ▁volunt arily ▁by ▁a ▁space craft ▁manufact urer ▁or ▁operator , ▁or ▁brought ▁into ▁effect ▁through ▁a ▁commercial ▁contract ▁between ▁a ▁customer ▁and ▁supp lier , ▁or ▁used ▁as ▁the ▁basis ▁for ▁establish ing ▁a ▁set ▁of ▁national ▁reg ulations ▁on ▁space ▁de br is ▁mit ig ation ." ▁The ▁volunt ary ▁ISO ▁standard ▁also ▁adopted ▁the ▁" 2 5 - year ▁rule " ▁for ▁the ▁" LE O ▁protected ▁region " ▁below ▁ 2 0 0 0 ▁km ▁alt itude ▁that ▁has ▁been ▁previously ▁( and ▁still ▁is , ▁as ▁of ▁ 2 0 1 9 ) ▁used ▁by ▁the ▁US , ▁E SA , ▁and ▁UN ▁mit ig