Thunderbirds Are Go: S3 E3 - Deep Search Thunderbirds Are Go
On Jupiter's moon Europa Buddy and Ellie Pendergast are searching for extra terrestrial life. When they start drilling into the ice pressure from geysers causes the ice to crack and they fall into an underground ocean below a ten mile thick layer of ice. Alan and Gordon blast off in Thunderbird 3, with Thunderbird 4 modified with skis, powerful engines and a heat drill to penetrate the ice, which they lose due to strong underwater currents. They find the Pendergasts, who have taken shelter in their rover, but before they leave they detect a lifeform. As their escape icehole freezes over Alan begins to regret his decision to observe the lifeform.