Overview of mid-infrared observatories

An overview of past and future space-borne observatories at mid-infrared wavelengths is given. The Infrared Space Observatory (ISO) was operational from November 1995 -- April 1998 and provided the first opportunity for spectroscopic observations over the complete 2.4-200 μm wavelength range above the atmosphere. This wavelength range is very rich in atomic and molecular lines as well as solid-state features, and some examples of exciting new results will be given, with special attention to molecular data needs. Future observatories such as SIRTF, SOFIA and FIRST will build and improve on the ISO results, either in sensitivity, spectral resolution and/or wavelength coverage. The complementarity with the ground-based Atacama Large Millimeter Array (ALMA), which will become operational in the same time-frame, will be discussed as well.