From Season 2, Episode 18.
Original Airdate: January 23, 1966.
When the Van Allen radiation belt catches fire, Nelson’s plan to extinguish the blaze is thwarted by a misguided U.N. official.

This episode is almost an exact copy of the plot for the movie “Voyage to the Bottom of the Sea” on which the series was based. You might wonder if they could do that, well if you’re Irwin Allen, who was the producer and director of both the movie and the series and also co-wrote the movie, then there is no reason not to recycle a perfectly good script and special effects.