Hubble is pretty big. When it launched in 1990, it was the world's first space telescope. At roughly the size of a school bus, this was one big machine. Nearly three decades later, its successor is gearing up for launch, and its scale is unparalleled. The James Webb Space Telescope, slated for a 2018 launch, is closer to the size of a 737.

With greater scale comes greaterresolution, and the James Webb Space Telescope is meant to bring just that — a closer look at the things we've seen with Hubble, and a first look at the things that have gone unnoticed by our first space telescope.

This behemoth will enter orbit in a folded orientation, at a distance of roughly one million miles from Earth (that's a lot farther than the Moon). It'll unfold itself over a couple weeks, at which point, it'll be ready for action.

Check out the clip below from National Geographic to hear a bit more about the JWST. When the video's over, be sure to let us know what you thought in the comments, and share it with your friends on Facebook!