It's been more than 20 years since scientists set their sights on creating a successor for the Hubble telescope.Now, the James Webb Space Telescope — a $10 billion infrared instrument — is set to launch and begin its million-mile journey away from Earth on Dec. 24.What will it help us discover? And what's at stake?We meet one of the head scientists behind the telescope — plus, three astronomers whose future work hinges on the discoveries of the mission.Want to support 1A? Give to your local public radio station and subscribe to this podcast. Have questions? Find us on Twitter @1A.