br is ▁to ▁a ▁central ▁station . ▁One ▁such ▁system ▁is ▁Space ▁In frastr ucture ▁Serv icing , ▁a ▁commer cially ▁developed ▁ref uel ing ▁dep ot ▁and ▁service ▁space craft ▁for ▁communic ations ▁sat ell ites ▁in ▁ge os ynchronous ▁orbit ▁originally ▁scheduled ▁for ▁a ▁ 2 0 1 5 ▁launch . ▁The ▁S IS ▁would ▁be ▁able ▁to ▁" push ▁dead ▁sat ell ites ▁into ▁gra vey ard ▁or bits ." ▁The ▁Advanced ▁Common ▁E vol ved ▁Stage ▁family ▁of ▁upper ▁stages ▁is ▁being ▁designed ▁with ▁a ▁high ▁le f to ver - prop ell ant ▁margin ▁( for ▁der el ict ▁capture ▁and ▁de - or bit ) ▁and ▁in - space ▁ref uel ing ▁cap ability ▁for ▁the ▁high ▁delta - v ▁required ▁to ▁de - or bit ▁heavy ▁objects ▁from ▁ge os ynchronous ▁orbit . ▁A ▁t ug - like ▁satellite ▁to ▁drag ▁de br is ▁to ▁a ▁safe ▁alt itude ▁for ▁it ▁to ▁burn ▁up ▁in ▁the ▁atmosphere ▁has ▁been ▁research ed . ▁When ▁de br is ▁is ▁identified ▁the ▁satellite ▁creates ▁a ▁difference ▁in ▁potential ▁between ▁the ▁de br is ▁and ▁itself , ▁then ▁using ▁its ▁thrust ers ▁to ▁move ▁itself ▁and ▁the ▁de br is ▁to ▁a ▁sa fer ▁orbit . ▁ ▁A ▁variation ▁of ▁this ▁approach ▁is ▁for ▁the ▁rem ot ely ▁controlled ▁vehicle ▁to ▁rende z vous ▁with ▁de br is , ▁capture ▁it ▁tempor arily ▁to ▁attach ▁a ▁smaller ▁de - or bit ▁satellite ▁and ▁drag ▁the ▁de br is ▁with ▁a