Replacing a technology: The large space telescope and CCDs

The Hubble Space Telescope is due to be launched in 1986. It is certainly the chief space astronomy initiative of the 1980s, perhaps of the late twentieth century. It is to carry six scientific instruments, and in this paper we investigate the debate on the choice of detectors for what was seen as the chief instrument during the project definition phase, the so-called wide-field camera. In the end CCDs were selected, despite the fact that this decision had to be made a mere seven years after the concept on which they are based was published. We argue that this rapid development of CCDs as astronomical detectors was due to a strong mix of "market pull" and "invention push" together with the very active interest of one group within the astronomical community, planetary scientists.