Alan Shepard was a 20th century NASA astronaut and the first American in space. He was among the first few Humans to have ever walked on the surface of the moon. (VOY: "Future's End")
Rain Robinson had a photograph of Shepard standing on the moon displayed near her computer at the Griffith Observatory. (VOY: "Future's End")
The 23rd century Federation USS Shepard was named in his honor. (Star Trek IV: The Voyage Home)
Footage of Shepard prior to his 1971
Apollo 14 moon flight were featured in the opening credits for Star Trek: Enterprise.