The models of the Thunderbird vehicles seen on the table in front of Jeff in the opening scene were commercially available at the time of this episode's initial broadcast (25 December, 1966). They are the "Thunderbirds" model toys produced by J. Rosenthal (Toys) Ltd. Unfortunately, Rosenthal's Thunderbird 5 didn't look very much like the genuine article, so it does not appear in this scene.
This is the only episode where Lady Penelope is featured without her chauffeur Parker.
A wall calendar indicates that this episode takes place in December 2026. According to series co-creator Gerry Anderson and art director Bob Bell, this is a production design error and should instead say 2066 - a hundred years into the future from when this episode was first aired.
As Thunderbird 3 is prepped for launch (all 287 feet of it), the audience can see in detail how the pilot Alan is brought to the rocket, sitting comfortably on what looks like a sofa.
Brains' snow-making surprise was based on a concept first used by ski resorts in the 1950's. The practice was on the verge of becoming mainstream just a few years after this episode aired.