The Universe is continually radiating a wealth of information to Earth, sending signals in a wide spectrum of light.  However, not all of these messages reach the ground. Because our planet's atmosphere blocks most radiation coming in from space, humans need to launch telescopes beyond it to get a complete cosmic picture.   

Many of the Universe's messages are transmitted in thermal infrared light, which our sky heavily filters. In space, any object that has a temperature above zero Kelvin (-459.67 degrees Fahrenheit, or -273.15 degrees Celsius) radiates in the infrared.

For years, astronomers have tried to place telescopes above the atmosphere, to catch a glimpse of an otherwise hidden infrared universe. This section explores the heritage of infrared astronomy, which culminates with NASA's Spitzer Space Telescope - the most sensitive infrared space observatory ever launched.

The Road to Spitzer and Beyond

In the science journals there are a number of review articles covering aspects of the history of infrared astronomy. These include (not a complete list): 

"History of Infrared Telescopes and Astronomy" in Experimental Astronomy, Volume 25, 2009. Author: G. H. Rieke.

"The Short History of Infrared Space Telescopes" in Astronomische Nachrichten, Volume 330, 2009. Author: D. Lemke.

"The Beginning of Modern Infrared Astronomy" in the Annual Review of Astronomy and Astrophysics, Volume 45, 2007. Authors: Frank J. Low, G.H. Rieke, and R.D. Gehrz.

"A Brief History of Infrared Astronomy" in Astronomy & Geophysics, Volume 41, 2000. Author: Helen J. Walker.

Note that some of these articles may require individual or institutional subscriptions.

In 2008, Steve Price published an article "History of Space-Based Infrared Astronomy and the Air Force Infrared Celestial Backgrounds Program." It is a retrospective on space-based astronomy missions and the prominent role the US Defense Department (DoD), particularly the Air Force, played in early days of infrared astronomy and the technology development that was transitioned to the infrared astronomical community. It covers up to the early Spitzer era, and looks forward to missions still in the queue at the time, including WISE and JWST. The article is available here.