Les is the author or co-author of multiple popular science and science fiction books.

He was the featured Interstellar Explorer in the January 2013 issue of National Geographic Magazine in their issue "celebrating 125 years of exploration," appeared again in the March 2019 issue, and was featured on Public Radio's Science Friday.

Les frequently speaks to the general public about space and science. He regularly speaks to civic and community groups throughout the southeastern United States and has done so in public forums in four countries. One student at the Tec de Monterey in Monterey, Mexico told him that he was "bigger than a rock star." (Now that's something a physicist does not hear very often!) He was the technical consultant for the movies Europa Report and Lost in Space. NPR, CNN, Fox News, The Science Channel and The Discovery Channel have all interviewed him about space and space exploration. He appeared on the Discovery Science Channel in three episodes of their series about interplanetary and interstellar exploration called Exodus Earth, National Geographic Channel's series How to Survive the End of the World and Evacuate Earth.