Q. Whatever happened to Billy Mumy of "Lost in Space"? Is he doing any televsion? Is he married? -M.J., Panama City Beach, Fla.

A. Stats: Born Feb. 1, 1954, in San Gabriel, Calif., as Charles William Mumy Jr. Educated by studio tutors, public school. Married.Early years: Mumy made his TV debut in Los Angeles' "Romper Room" at 6; then did commercials, TV guest roles and features ("Tammy Tell Me True," "A Child Is Waiting," "Palm Springs Weekend"). He was 11 when he was cast as Will Robinson in "Lost in Space."

Famous for: For three seasons he zoomed around "Lost in Space." "What kid wouldn't like flying around with robots all day," he has said of those days. "You got to put on your superhero outfit and attack giant monsters."

In recent years: Mumy left acting for three years to write and compose music. When he returned to acting, he did the feature "Papillion" and the 1975 series "Sunshine." He toured with Shaun Cassidy's band, played with the rock band America. He acts occasionally (a 1988 "Matlock"), writes adventures for Marvel Comics and plays with the band Barnes & Barnes.

- Send questions to Whatever happened to . . ., Detroit Free Press, 321 W. Lafayette Blvd., Detroit, MI 48226.