He is best known for playing Dr. Gordon Briscoe in
The Quatermass Experiment (1953). The serial's storyline concerns the first three humans to journey into outer space and to orbit the Earth. On February 20, 1962, his near namesake
John Glenn became the fifth person in space as well as the first American to orbit the Earth. He was the second person overall to orbit the Earth after the first person in space, the Soviet cosmonaut
Yuri Gagarin on April 12, 1961.