▁the ▁orb ital ▁plane . ▁Close ▁approaches ▁( with in ▁ 5 0 ▁meters ) ▁are ▁estimated ▁at ▁one ▁per ▁year . ▁The ▁collision ▁de br is ▁pose ▁less ▁short - term ▁risk ▁than ▁from ▁an ▁LE O ▁collision , ▁but ▁the ▁satellite ▁would ▁likely ▁become ▁in oper able . ▁Lar ge ▁objects , ▁such ▁as ▁solar - power ▁sat ell ites , ▁are ▁especially ▁vulner able ▁to ▁coll isions . ▁ ▁Although ▁the ▁IT U ▁now ▁requires ▁proof ▁a ▁satellite ▁can ▁be ▁moved ▁out ▁of ▁its ▁orb ital ▁slot ▁at ▁the ▁end ▁of ▁its ▁lif es pan , ▁studies ▁suggest ▁this ▁is ▁ins u fficient . ▁Since ▁G E O ▁orbit ▁is ▁too ▁distant ▁to ▁accur ately ▁measure ▁objects ▁under ▁, ▁the ▁nature ▁of ▁the ▁problem ▁is ▁not ▁well ▁known . ▁Sat ell ites ▁could ▁be ▁moved ▁to ▁empty ▁sp ots ▁in ▁G E O , ▁requiring ▁less ▁man e uv ring ▁and ▁making ▁it ▁easier ▁to ▁predict ▁future ▁motion . ▁Sat ell ites ▁or ▁boost ers ▁in ▁other ▁or bits , ▁especially ▁str and ed ▁in ▁ge ost ation ary ▁transfer ▁orbit , ▁are ▁an ▁additional ▁concern ▁due ▁to ▁their ▁typically ▁high ▁crossing ▁velocity . ▁ ▁Despite ▁efforts ▁to ▁reduce ▁risk , ▁space craft ▁coll isions ▁have ▁occurred . ▁The ▁European ▁Space ▁Agency ▁tele com ▁satellite ▁Olymp us - 1 ▁was ▁struck ▁by ▁a ▁meteor oid ▁on ▁ 1 1 ▁August ▁ 1 9 9 3 ▁and ▁eventually ▁moved ▁to ▁a ▁gra vey ard ▁orbit . ▁On ▁ 2 9 ▁March