The Hubble Space Telescope, which was designed for extreme servicing, you know, we can fix everything. And the James Webb Space Telescope, where we can fix nothing. It has to work the first time. And it's a very complicated telescope.

When I grew up as a kid, we didn't know there were any other planets outside of our own solar system. It was widely speculated that planet formation was an incredibly rare event and that it's possible that other planets just don't exist in our galaxy, and it's just this special situation where we happen to have planets around our sun.

Hubble uniquely has been able to look in the atmosphere of a planet orbiting a nearby star and figure out what's in that atmosphere.

John M. Grunsfeld Quotes