Oh, both. [Luke looks up at the nearest X-wing, and begins pointing out the parts as he speaks-] You see how the wings are extended? Those are X-foils, they keep the engines from overheating on long flights, or when you pick up speed. That way, you can have a hyperdrive in something as small as a starfighter without risking malfunction, or the instruments going haywire in atmosphere.

[He is more than happy to talk about space with you, Sans, especially if it involves his absolute favorite ship. Not that he's biased, you know.]