▁or ▁are ▁fully ▁autonom ous . ▁ ▁Space fl ight ▁is ▁used ▁in ▁space ▁expl oration , ▁and ▁also ▁in ▁commercial ▁activities ▁like ▁space ▁tour ism ▁and ▁satellite ▁tele communic ations . ▁Add itional ▁non - com mer cial ▁uses ▁of ▁space fl ight ▁include ▁space ▁observ ator ies , ▁reconna issance ▁sat ell ites ▁and ▁other ▁Earth ▁observation ▁sat ell ites . ▁ ▁Space fl ight ▁can ▁be ▁achieved ▁with ▁different ▁types ▁of ▁launch ▁systems , ▁convention ally ▁by ▁ro cket ▁launch ing , ▁which ▁provide ▁the ▁initial ▁thrust ▁to ▁overcome ▁the ▁force ▁of ▁gravity ▁and ▁prop el ▁a ▁space craft ▁from ▁the ▁surface ▁of ▁the ▁Earth . ▁Once ▁in ▁space , ▁the ▁motion ▁of ▁a ▁space craft   – ▁both ▁when ▁un prop elled ▁and ▁when ▁under ▁prop ulsion   – ▁is ▁covered ▁by ▁the ▁area ▁of ▁study ▁called ▁ast rod ynam ics . ▁Some ▁space craft ▁remain ▁in ▁space ▁in def initely , ▁some ▁dis integr ate ▁during ▁atmos pher ic ▁re entry , ▁and ▁others ▁reach ▁a ▁planet ary ▁or ▁lun ar ▁surface ▁for ▁landing ▁or ▁impact . ▁ ▁History ▁▁ ▁The ▁first ▁theoretical ▁proposal ▁of ▁space ▁travel ▁using ▁rock ets ▁was ▁published ▁by ▁Scottish ▁astronom er ▁and ▁math ematic ian ▁William ▁Le itch , ▁in ▁an ▁ 1 8 6 1 ▁ess ay ▁" A ▁J our ney ▁Through ▁Space ". ▁More ▁well - known ▁( though ▁not ▁widely ▁outside ▁Russia ) ▁is ▁Konst antin ▁T si ol kov sky ' s ▁work , ▁"" ▁( The ▁Ex