StarTrek.com is saddened to report the passing of Robert Walker Jr., the actor who played the titular role in Star Trek: The Original Series episode “Charlie X.” Walker Jr. passed at age 79, according to his family.

StarTrek.com "Charlie X"

In “Charlie X,” penned by D.C. Fontana, Walker Jr.’s Charlie is the sole survivor of a shuttle crash that left him marooned for years with only a computer for company. Kirk and the crew rescue him, but it soon is revealed that he possesses powers that make him very dangerous. It was the second episode of the series.

Of working with Walker Jr., Fontana told StarTrek.com in 2013, “I loved the work Robert Walker Jr. did... the ending I had written was retained - with Charlie being taken away where he could do no harm, but where he would never be with anyone he could ever really touch.”

StarTrek.com "Charlie X"

Apart from Star Trek, his television credits included Bonanza, Route 66, Charlie’s Angels, Colombo, and Murder, She Wrote. His film credits include Ensign Pulver, Young Billy Young, and Easy Rider.

The son of Robert Walker and Jennifer Jones and step-father, Hollywood producing legend David O. Selznick, Walker Jr. is survived by three children. StarTrek.com extends their condolences to his family and fans around the world.