▁of ▁per ch lor ate ▁or ▁other ▁chemical s , ▁and ▁this ▁can ▁cause ▁temporary ▁local ▁holes ▁in ▁the ▁o zone ▁layer . ▁Re - ent ering ▁space craft ▁generate ▁nit r ates ▁which ▁also ▁can ▁tempor arily ▁impact ▁the ▁o zone ▁layer . ▁Most ▁rock ets ▁are ▁made ▁of ▁met als ▁that ▁can ▁have ▁an ▁environmental ▁impact ▁during ▁their ▁construction . ▁ ▁In ▁addition ▁to ▁the ▁atmos pher ic ▁effects ▁there ▁are ▁effects ▁on ▁the ▁near - E arth ▁space ▁environment . ▁There ▁is ▁the ▁possibility ▁that ▁orbit ▁could ▁become ▁in access ible ▁for ▁gener ations ▁due ▁to ▁expon entially ▁increasing ▁space ▁de br is ▁caused ▁by ▁sp alling ▁of ▁sat ell ites ▁and ▁vehicles ▁( K ess ler ▁synd rome ). ▁Many ▁launched ▁vehicles ▁today ▁are ▁therefore ▁designed ▁to ▁be ▁re - enter ed ▁after ▁use . ▁ ▁App lications ▁▁ ▁Current ▁and ▁proposed ▁applications ▁for ▁space fl ight ▁include : ▁ ▁Earth ▁observation ▁sat ell ites ▁such ▁as ▁Sp y ▁sat ell ites , ▁weather ▁sat ell ites ▁ ▁Space ▁expl oration ▁ ▁Communic ation ▁sat ell ites ▁ ▁Sat ellite ▁television ▁ ▁Sat ellite ▁navigation ▁ ▁Space ▁tour ism ▁ ▁Prote ct ing ▁Earth ▁from ▁Pot entially ▁ha z ard ous ▁objects ▁ ▁Space ▁colon ization ▁ ▁Most ▁early ▁space fl ight ▁development ▁was ▁paid ▁for ▁by ▁govern ments . ▁However , ▁today ▁major ▁launch ▁mark ets ▁such ▁as ▁Communic ation ▁sat ell ites ▁and ▁Sat ellite ▁television ▁are ▁purely ▁commercial , ▁though ▁many ▁of ▁the ▁launch ers ▁were