 Widely considered to be the Andersons ' most popular and commercially successful series , Thunderbirds has received particular praise for its effects ( directed by Derek Meddings ) and musical score ( composed by Barry Gray ) . It is also well remembered for its title sequence , which opens with an often @-@ quoted countdown by actor Peter Dyneley ( who voiced the character of Jeff ) : " 5 , 4 , 3 , 2 , 1 : Thunderbirds Are Go ! " A real @-@ life rescue service , the International Rescue Corps , is named after the organisation featured in the series . 
