 Set in the mid @-@ <unk> , Thunderbirds is a follow @-@ up to the earlier Supermarionation productions Four Feather Falls , Supercar , <unk> <unk> and Stingray . It follows the exploits of International Rescue ( IR ) , a life @-@ saving organisation equipped with technologically @-@ advanced land , sea , air and space rescue craft ; these are headed by a fleet of five vehicles named the Thunderbirds and launched from IR 's secret base in the Pacific Ocean . The main characters are ex @-@ astronaut Jeff Tracy , the founder of IR , and his five adult sons , who pilot the Thunderbird machines . 
