20thcentury aerodynamics aeronautics aerospaceplanes appropriationsandexpenditures armedforces armsrace astronautics ballisticmissiledefenses decisionmaking environmentalaspects environmentalaspectsofmilitaryweapons environmentalaspectsofwar environmentalprotection finance governmentpolicy history hydrogenbomb hypersonic internationalcooperation military militarypolicy militaryweapons nationalsecurity outerspace peace procurement research spacecontrol(militaryscience) spacesecurity spaceshuttles spacestations spacewarfare strategicaspects strategicdefenseinitiative unitedstates war weaponssystems x-20(spaceglider)