[There's a particular kind flustered frustration that sometimes leads to Papyrus stomping a foot, and while he doesn't actually risk banging a foot on any of the eyes, the feeling rings out after Sans's annoying older sibling energy. But it's shoved aside with the rest when he focuses on the Very Seriousness, and space, and whatnot.]

Yes, exactly! You've caught on to my thoughts. Why put effort into rocket science, as entertaining, and explosive, as it is... When you can go to space, and get exercise out of it!

[You know, hypothetically. In this imagined scenario where they figure out some way to clear the tunnel without people or machines having problems, or get airbound without having problems, or... something, to get out.]