The lead characters are ex-astronaut Jeff Tracy, founder of International Rescue, and his five adult sons, who pilot the organisation's primary vehicles: the Thunderbird machines.
In 1967, Century 21 released a condensed audio adaptation of "Day of Disaster" on EP record (Thunderbirds, catalogue number MA 121), with narration by David Graham in character as Gordon Tracy.
Two technicians, Bill and Frank, are aboard the probe rocket carrying out pre-flight checks while it is driven to the launch site on the back of a transporter truck.
Trapped in the nose cone, Bill and Frank discover that the impact has triggered the probe's automatic launch countdown: after 12 hours, the rocket will blast off from this compromised position and inevitably be destroyed.
Penelope and Parker fire the car's machine gun at some abandoned warehouses, distracting the emergency services and enabling Brains to slip into the bridge control room, where the personnel are arranging to lift the rocket out of the river using a floating crane.
[5] Sam Denham describes "Day of Disaster" as a "classic 'doomed technology' episode" of Thunderbirds, commenting that its premise about an ill-fated space probe is one of several that "reflected a growing concern in the 1960s that the pace of progress may have been moving too fast".
He adds that judging by the guest characters' surprised reactions to Brains and Penelope's communication devices, the episode may be implying "there are certain types of technology that only International Rescue can be trusted with".
He adds that psychiatrist Dr Korda "is, of course, Austrian", while the presence of an American space probe in Britain "presents a refreshing picture of Anglo-American relations".