In a trailer for the highly-anticipated film, First Man, starring Ryan Gosling as astronaut Neil Armstrong, scenes from the movie are shown with no dialogue. Instead, we hear John F. Kennedy’s words from his Moon Shot Speeches delivered to Congress in 1961 and the following year in a rousing address at Rice University.

Andrew Carton, a management professor at Wharton, analyzed thousands of pages of documents including conversations, speeches and employee interviews to uncover how Kennedy convinced a nation to take the bold steps necessary for the dangerous mission. In the early 1960s, many scientists were skeptical that a moon landing could be accomplished by the end of the decade. How did Kennedy change hearts and minds?

What Carton discovered not only helps us understand the events that led up to the Apollo 11 mission, it gives all leaders a better understanding of the role that words play in galvanizing people to reach audacious goals. Carton found that Kennedy used four communication devices to make a strong connection between a NASA employees’ day-to-day role and the ultimate goal. “I’m not mopping floors,” a custodian once said, “I’m putting a man on the moon.”

Step 1. Kennedy reduced the number of NASA’s aspirations to one. Prior to Kennedy becoming president in 1961, NASA’s vision was overly broad. The space agency wanted to establish ‘superior technology’ to ‘achieve preeminence in space’ and to ‘advance science,’ etc. Kennedy realized that one goal is better than three or four. He distilled NASA’s multi-faceted vision to one target. “Our aim is to develop a new frontier in science,” Kennedy said.

Step 2. Kennedy shifted from the aspirational vision to concrete objectives. On May 25, 1961, Kennedy told Congress 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.” Putting a date on a goal triggers action.

Step 3. Kennedy communicated milestones. From 1961 to the day Neil Armstrong stepped foot on the moon, there were many milestones along the way. The Mercury program put an astronaut in orbit. Gemini achieved the task of docking in space. Apollo was meant to put all of the final elements in place to make the moon landing a reality. Kennedy –and other NASA leaders—created a metaphorical “ladder” of milestones that were clearly articulated and checked-off along the way.

Step 4. Kennedy made the abstract, tangible. Kennedy–a poet and a president–relied on emotional rhetorical techniques to inspire his audiences. For example, in 1962 at Rice University, Kennedy said:

But why, some say, the moon? Why choose this as our goal? And they may well ask why climb the highest mountain? Why, 35 years ago, fly the Atlantic? Why does Rice play Texas? [Kennedy wrote this line in the speech at the last minute. He knew it would fire up the crowd of 40,000 people]. We choose to go to the moon. We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard.

Kennedy used metaphorical language to tie it all together. He compared the moon mission to another famous mission that most people understood and admired at the time: “Many years ago the great British explorer George Mallory, who was to die on Mount Everest, was asked why did he want to climb it. He said, ‘Because it is there.’ Well, space is there, and we’re going to climb it, and the moon and the planets are there, and new hopes for knowledge and peace are there.’”

Kennedy ended his Moon Speech with the metaphor that we would collectively “set sail” on the most “hazardous and dangerous and greatest adventure.”

Kennedy also used inclusive pronouns to establish a collective sense of identify and effort. It wasn’t about him; it was about “our,” “us” and “we.” Kennedy used the word “we” forty-five times in his speech at Rice University.

Solving some of the greatest challenges of our time will require big, bold, inspiring goals to make it happen. Kennedy’s strategy to fuel the 1960s space program carries a lesson for all leaders who need to rally people around a common goal.