Yeah, that guy's absolutely a domain expert! But note that he writes -55 km, not +55 km—that is a suborbital trajectory. Its perigee is below the earth's surfac

Yeah, that guy's absolutely a domain expert! But note that he writes -55 km, not +55 km—that is a suborbital trajectory. Its perigee is below the earth's surface; -55 km is a negative altitude. (He's also clearly using a different set of data than I have access to. I can't read the context of the Twitter thread so I don't know what numbers he's looking at).