Explorers on the Moon: Part 1 - S3-E11
Plot hole: Where did Thomson and Thompson get the pyjamas from? Tintin, Haddock, Calculus and Wolff did not bring any pyjamas aboard the shuttle with them because they were planning on sleeping in their clothes and Thomson and Thompson were only on the rocket because they were inspecting it before take-off, so they wouldn't have brought anything with them. (00:16:30)
Chosen answer: It is a pill that makes alcohol taste disgusting.