May 25 is an important date for Star Wars fans. It also represents a milestone for the U.S. space program.

Star Wars debuted May 25, 1977. The movie won 7 Oscars and rang up $461 million in U.S. ticket sales ($1.6 billion in 2010 dollars). Its ground-breaking special effects captivated audiences with an action/adventure story set deep in space.

Sixteen years earlier, a real life space adventure was beginning. The Soviet Union and the U.S. were locked in a race to space with the Soviets besting the Americans by launching the first satellite in 1957 (Sputnik 1); first unmanned moon landing in 1959 (Luna 2); and the first human in space and first human earth orbit in 1961 (Yuri Gagarin).

In fact it was Gagarin’s earth orbit on April 12, 1961, that motivated the Kennedy administration to conduct at top-to-bottom review of the U.S. space program and develop an ambitious set of goals. At the top of the list: a manned moon mission.

President John F. Kennedy issued the challenge on May 25, 1961, in a speech to a joint session of Congress:

“I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important in the long-range exploration of space; and none will be so difficult or expensive to accomplish.”

Kennedy didn’t just issue a challenge, he urged Congress to provide boost NASA’s budget by $531 million the following year to jump start the space program. By the time Neil Armstrong stepped on the moon July 20, 1969, the U.S. had spent about $24 billion on the Apollo program. Adjusted for inflation, the Apollo program would cost $156.7 billion in 2015 dollars.