The Webb Space Telescope Will Rewrite Cosmic History. If It Works

One morning in 1987, the astrophysicist Riccardo Giacconi, who was then the director of the Space Telescope Science Institute and of the yet-to-launch Hubble, asked deputy director Garth Illingworth to start thinking about Hubble's successor. Illingworth, who is from Australia, got together with his STScI colleagues Pierre Bely of France and Peter Stockman of the U.S. to brainstorm about the next-generation space telescope. For an IR telescope to be as sensitive as Hubble, which has a 2.4-meter-wide primary mirror, Illingworth, Bely and Stockman realized that it would need to be significantly bigger, since it detects bigger wavelengths. Rather than actively cool the telescope, they thought to exploit the extreme frigidity of outer space by blocking the heat of the Earth, moon and sun. Their vague conception of a large, passively cooled infrared telescope, greatly elaborated upon, would become the cargo now awaiting launch in Kourou. Leading astronomers convened at STScI in 1989 to discuss the science that an infrared space telescope might be good for. Mather calls himself a "Theoretical instrument builder." He started building telescopes as a kid in pastoral New Jersey, assembling parts from catalogs in the hope of getting a closer look at the surface of Mars.