system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do space travel vehicles usually get launched from static vertical positions? Would it be more energy efficient to take off like an airplane then accelerate while gaining altitude?
gpt
The problem is the atmosphere; down near the surface, the atmosphere is thick enough to cause significant drag (and potentially damage) to any ship that's going to want to get to the very high speeds needed for achieving orbit.

So instead, rockets will launch more or less straight up, and then when they've gotten high enough that the atmosphere is sufficiently thin, they'll nose over and start gaining speed parallel(ish) to the Earth's surface.