Sub-millimeter and far-infrared technology in the Herschel Space Observatory and beyond

The electromagnetic spectrum at wavelengths longer than 50 microns (∼6 THz), contains approximately half the total power emitted in the Universe since the big bang. Additionally, the spectral region also contains the transition between the dust being optically thick and optically thin, as well as numerous transitions of atoms and molecules which can be used to study the physical, chemical and structural details of the interstellar medium. The majority of this spectral region is completely obscured from the surface of the Earth, due to absorption of water vapor in the atmosphere. The Herschel Space Observatory is the first comprehensive far-Infrared telescope facility covering 670–57 microns with three instruments. The current limitations and potential improvements of the current generation of far-infrared systems will be discussed in light of the astrophysical application.