In the episode "La Bomba", Crichton writes "HI THERE" on the side of the nuclear bomb that he's carrying. In the next episode, he writes "DEAR JOHN" on another nuclear bomb. These are both references to the 1964 Stanley Kubrick movie Dr. Strangelove, in which there are two nuclear bombs in a B-52 with both of those phrases written on them. In that movie Major Kong (Slim Pickens) rides a bomb as is dropped on the Soviet Union. Presumably, Crichton feels he is doing the same, travelling into an enemy stronghold with "mankind's greatest contribution to the absurd."
The full title of the movie is Dr. Strangelove or: How I Learned to Stop Worrying and Love the Bomb.