Abstract :
During its 25 years, the Hubble Space Telescope has become an iconic instrument and its spectacular images have had an important impact on the public perception of science, and astronomy in particular. NASA follows the iconic Hubble with the James Webb Space Telescope (JWST), which is planned for launch in 2018. Although we may consider JWST to be the son, or possibly younger brother of the Hubble, it is interesting to contrast the two telescopes in a technical sense. While JWST is the scientific successor of HST, it is a very different type of telescope. JWST will observe exclusively in the infrared, while HST was mostly an optical and ultraviolet telescope, with some capability in the near infrared.
