 Seeking to distinguish his 26 @-@ episode proposal from APF 's earlier productions , Anderson attempted to pitch stories at a level that would appeal to both adults and children . Whereas previous series had been shown during the late afternoon , Anderson wanted Thunderbirds to be broadcast in a family @-@ friendly primetime slot . Sylvia remembers that " our market had grown and a ' kidult ' show ... was the next step . " The Andersons retired to their holiday villa in Portugal to expand the premise , script the pilot episode and compose a scriptwriters ' guide . According to Sylvia , the writing process depended on a " division of labour " , whereby Gerry created the action sequences while she managed characterisation . The decision to make a father and his sons the main characters was influenced by the premise of Bonanza , as well as Sylvia 's belief that the use of more than one heroic character would broaden the series ' appeal . The Tracy brothers were named after Mercury Seven astronauts : Scott Carpenter , John Glenn , Virgil " Gus " Grissom , Gordon Cooper and Alan Shepard . 
 Seeking to distinguish his 26 @-@ episode proposal from APF <a href='null_genetive' title='1'><mark>'s</mark></a>earlier productions , Anderson attempted to pitch stories at a level <a href='null_relcl' title='2'><mark>that</mark></a>would appeal to both adults and children . Whereas previous series <a href='been_done' title='3'><mark>had</mark></a> been shown during the late afternoon , Anderson wanted Thunderbirds to be broadcast in a family @-@ friendly primetime slot . Sylvia <a href='uninflect' title='4'><mark>remembers</mark></a> that " our market <a href='been_done' title='5'><mark>had</mark></a> grown and a ' kidult ' show ... was the next step . " The Andersons retired to their holiday villa in Portugal to expand the premise , script the pilot episode and compose a scriptwriters <a href='null_genetive' title='6'><mark>'</mark></a>guide . According to Sylvia , the writing process depended on a " division of labour " , whereby Gerry created the action <a href='uninflect' title='7'><mark>sequences</mark></a> while she managed characterisation . The decision to make a father and his sons the main characters was influenced by the premise of Bonanza , as well as Sylvia <a href='null_genetive' title='8'><mark>'s</mark></a>belief that the use of more than one heroic character would broaden the series <a href='null_genetive' title='9'><mark>'</mark></a>appeal . The Tracy brothers <a href='uninflect' title='10'><mark>were</mark></a> named after Mercury Seven astronauts : Scott Carpenter , John Glenn , Virgil " Gus " Grissom , Gordon Cooper and Alan Shepard . 
Seeking to distinguish his 26 @-@ episode proposal from APF  earlier productions , Anderson attempted to pitch stories at a level would appeal to both adults and children . Whereas previous series done been shown durin the late afternoon , Anderson wanted Thunderbirds to b broadcast in a family @-@ friendly primetime slot . Sylvia rememba that " our market done grown and a ' kidult ' show ... was da next step . " The Andersons retired to their holiday villa in Portugal to expand the premise , script the pilot episode and compose a scriptwriters  guide . According to Sylvia , the writing process depended on a " division of labour " , whereby Gerry created tdaaction sequence while she managed characterisation . Thdaecision to make a father and his sons the main characters was influenced by the premise of Bonanza , as well as Sylvia  belief that thedae of more than one heroic character would broaden the daies  appeal . The Tday brothers was named after Mercury Seven astronauts : Scott Carpenter , John Glenn , Virgil " Gus " Grissom , Gordon Cooper and Alan Shepard .