
Visible crew/equipment: When they listen to the sphere's signal to analyze it, in the shots of Rygel, D'Argo, and John, particularly when John asks, "What stopped?" just before the message that only the three Johns hear, we can see the brunette puppeteer with his arm up Rygel's sleeve, at the right side of the screen.
Chosen answer: It's never explained. John mentions a theory that his less technologically developed craft simply interferes with the wormhole less than the "superior" Vipers, but they never make a concrete determination on that point. But we also have to take into account the fact that Moya traverses wormholes with no ill effect as well.
Garlonuss ★