Two Representative THz Telescopes

In this section we will provide an overview of two satellite instruments, the Submillimeter-Wave Astronomy Satellite (SWAS) and the Far Infra-Red and Submillimeter Telescope (FIRST), which has been renamed the Herschel Space Observatory. These two telescopes differ by about a decade in their launch dates and technological development. For each, we will focus on the relation between the Submillimeter /Terahertz technologies and the astronomical problems that motivated their design.