In this episode we celebrate 15 years of the Spitzer Space Telescope. The infrared telescope, one of NASA's "Great Observatory" has helped revolutionize our understanding of the cosmos. Dave is joined by three top scientists from the Spitzer mission. Lisa Storrie Lombardi is the Project Manager and describes the telescope and its operations from an engineering standpoint. Then we are joined by Spitzer Science Center staff astronomer Sean Carey who describes some of the amazing discoveries made by Spitzer and finally, the dean of the Spitzer staff, Mike Werner, who has been with the project since its inception shares his insights from decades of work on the infrared observatory. Learn about seeing the invisible universe through the eyes of the chilled sensors of the Spitzer Space Telescope!