cket - power ed ▁aircraft ▁to ▁augment ▁its ▁inter ception ▁capabilities , ▁in ▁the ▁final ▁two ▁years ▁of ▁the ▁war , ▁it ▁had ▁been ▁able ▁to ▁deploy ▁aircraft ▁such ▁as ▁the ▁Mess ersch mitt ▁Me ▁ 1 6 3 ▁and ▁Bach em ▁Ba ▁ 3 4 9 ▁which , ▁via ▁ro cket ▁prop ulsion , ▁had ▁been ▁capable ▁of ▁un par alle led ▁rates - of - cl imb , ▁en abling ▁them ▁to ▁( at ▁least ▁in ▁theory ) ▁rapidly ▁sortie ▁to ▁intercept ▁enemy ▁bom bers ▁before ▁they ▁reached ▁their ▁targets . ▁As ▁the ▁performance ▁of ▁these ▁aircraft ▁had ▁become ▁increasing ly ▁well ▁known ▁to ▁the ▁Al lies , ▁R AF ▁exper ts ▁were ▁eager ▁to ▁explore ▁and ▁understand ▁the ▁underlying ▁technology . ▁ ▁In ▁the ▁after math ▁of ▁the ▁war , ▁German ▁ro cket ▁technology ▁was ▁studied ▁extens ively ▁by ▁various ▁members ▁of ▁the ▁former ▁Al lied ▁nations . ▁Britain ▁had ▁quickly ▁opt ed ▁to ▁commence ▁a ▁programme ▁to ▁develop ▁liquid - prop ell ant ▁rock ets ▁with ▁the ▁aim ▁of ▁boost ing ▁aircraft ▁during ▁the ▁take - off ▁phase , ▁known ▁within ▁the ▁R AF ▁as ▁ro cket - ass isted ▁take - off ▁g ear ▁( R AT O G ), ▁and ▁during ▁the ▁clim b - to - alt itude ▁phase ▁of ▁flight . ▁In ▁ 1 9 4 6 , ▁work ▁began ▁on ▁a ▁pair ▁of ▁new ▁British - built ▁ro cket ▁mot ors , ▁the ▁de ▁Hav ill and ▁Spr ite ▁with ▁a ▁maximum ▁thrust ▁of