In 1962, as John Glenn orbits the earth and sea turtles lay their eggs, as they have for millennia, on wild Florida beaches just miles from Cape Canaveral, eleven-year-old Linda Buckmaster becomes one of the first children to successfully undergo open-heart surgery. Encountering more of a problem than they anticipated, surgeons improvise a solution using Teflon, a material developed for the space industry.

Through the eyes of a rocket engineer's daughter, Space Heart paints a picture of an era of endless optimism and television cowboys amid the looming Soviet threat. Combining prose poems, narrative memoir, and history, Buckmaster juxtaposes the natural world of Space Coast Florida in the 1950s and 60s with the cutting-edge technology of the early days of the space race.

In the final stage of the memoir, Buckmaster leaves her home in Maine and returns to the Space Coast. On a trip with her troubled brother, she explores the remnants of an industry in decline and reckons with the memory of her alcoholic father.