Relativity - S3-E10
Visible crew/equipment: When Stark and Aeryn are back aboard Talyn with Xhalax, who is tied up, when Stark says, "As far as I can tell, Talyn's systems are almost back to normal," we can see the puppeteer's face (wearing a weird black mask) and hands under Rygel's hoverchair.
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 ★