The Man Who Reached for the Moon: The Legacy of Walter S. McAfee

Long before Neil Armstrong took his "one small step," a brilliant African American mathematician and physicist named Walter S. McAfee was busy proving that we could reach the celestial bodies with more than just our eyes. While his name might not be as instantly recognizable as some of his contemporaries, McAfee’s calculations were the invisible threads that first connected Earth to the Moon.

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A Mind Built for the Stars

Born in 1914 in Ore City, Texas, McAfee was one of nine children. His journey from a segregated South to the leading edge of the Space Age is a testament to his sheer intellectual force. After earning degrees from Wiley College and Ohio State University, he joined the U.S. Army Signal Corps Laboratory at Fort Monmouth, New Jersey, in 1942.

It was here, during the height of World War II and the dawn of the Cold War, that McAfee would make his most enduring mark on science.

Project Diana: Bouncing Radar off the Moon

In 1946, a top-secret project codenamed Project Diana aimed to determine if a high-frequency radio signal could penetrate the Earth’s ionosphere. The goal was simple but audacious: beam a radar signal at the Moon and see if it reflected back.

The engineering challenge was immense. To succeed, the team needed to account for the Doppler Effect—the change in frequency of a wave in relation to an observer moving relative to the source. Because the Earth is rotating and the Moon is orbiting, the "target" was constantly moving.

McAfee was the mathematical engine of the project. He calculated the precise radar cross-section of the Moon and predicted the required power and frequency shifts. On January 10, 1946, the team successfully detected the first echo from the Moon. This moment didn't just prove we could communicate through space; it effectively gave birth to radio astronomy.

The Hidden Figure of Fort Monmouth

Despite his pivotal role, McAfee was initially left out of the public news releases regarding Project Diana. It wasn't until the 25th anniversary of the event in 1971 that he was formally recognized for his contributions.

McAfee’s career continued to soar long after the Moon echo. He earned a Ph.D. from Cornell University (studying under Hans Bethe) and became the first African American to be promoted to GS-16, a high-level federal civil service rank. He spent decades contributing to:

• Nuclear weapons testing (high-altitude tracking)

• Satellite communications

• Electronic warfare sensors

A Lasting Impact

Walter S. McAfee passed away in 1995, but his legacy lives on through the McAfee Center at Fort Monmouth and various scholarships that support minority students in STEM. He was a pioneer who broke both scientific and social barriers, proving that the math doesn't care about the color of your skin—it only cares if you're right.

And McAfee was exactly right.