This is the only episode where Thunderbird 2 is not featured.
Though modern space technology allows for free flying space walks, the one shown here came just a year after the first attempt at space walking occurred. On March 18, 1965, cosmonaut Aleksey Leonov completed the first space walk for the USSR. American astronaut Ed White followed on June 3 that same year for the U.S. Gemini 4 mission.
Despite being set in the future, present day technology and artifacts were used to produce the show props. This included what appear to be the very latest 1960's models of analog television antenna.
The network of IR operatives is shown here, along with one of the other agents.
The astronaut refers to his lost tool as a spanner, the British term for a wrench.