The "5-4-3-2-1 - Thunderbirds are GO!" countdown voiceover is audio from the late Peter Dyneley, the voice of Jeff Tracy in the original Thunderbirds (1965) TV series.
Kayo is actually Tin Tin. The creators had to rename her Kayo as the name Tin Tin is copyright protected by The Adventures of Tin-Tin.
As a homage to the original series, you can see an orange juicer on the wall, in the launch room for Thunderbird 1.
Unlike the original 1965 series, International Rescue do not use guns in this remake as they're meant to save lives and not take them.