What do you believe was the most important aviation event during the Cold War

What do you believe was the most important aviation event during the Cold War generally considered to be the periods between 1947 and 1991.

FYI: The Cold War period included increased competition for global influence between the Soviets and the United States. Neither ever fought each other directly. Some say instead they fought ‘proxy wars’ in Korea and Vietnam in an attempt to further contain communism. Be careful with that.

A proxy war, may be a conflict instigated by opposing powers or allies of opposing powers, where the opposing powers do not participate in the fight, rather use third parties to do the fighting. In the case of Korea and Vietnam the U.S., an opposing power, participated directly.

Essay Requirements

Write a short, formal academic essay (about 750 words; 12 pt, double-spaced; unless quoting, third person, no contractions, no prepositions ending sentences. There should be in-text citations in APA format.). You should consult at least three references outside of the text for this activity.