A diagram of the Sun Probe from a TV report shows the solarnaut's control cabin within the Probe Module. But we later see that the control cabin is within the body of the Probe Rocket when the Module is fired into the solar prominence.
When Alan, Tin-Tin and Scott set off for Thunderbird 3 on the sofa, Alan is on the left, with Tin-Tin between him and Scott. As the sofa descends into the launch bay and ferries the trio to Thunderbird 3, Alan and Scott have swapped positions, but by the time the sofa arrives on board the spacecraft they are in their original positions again.
The is supposed to be Tin Tin's first mission but she accompanied Virgil on the previous mission in the Uninvited.
When Virgil and Brain land Thunderbird 2 in the snow-covered mountains the landing thrust should have melted the snow and ice directly below them.
At the launch of Sun Probe, Colonel Benson is voiced by David Graham but is voiced by Ray Barrett when he later appears on television.
When Alan faints, you can see the shadow of the puppeteer move near his head.