Far-IR/submillimeter space interferometry: scientific motivation and technology requirements

Far infrared interferometers in space would enable extraordinary measurements of the early universe, the formation of galaxies, stars, and planets, and would have great discovery potential. Half the luminosity of the universe and 98% of the photons released since the Big Bang appear at far-IR and submillimeter wavelengths (40 to 500 μm). Because the Earth´s atmosphere prevents sensitive observations from the ground at wavelengths shorter than about 300 μm, and large effective apertures are required to achieve sub-arcsecond angular resolution, this is one of the last unexplored frontiers of observational astronomy. We present the engineering and technology requirements that stem from a set of compelling scientific goals and discuss possible configurations for two proposed NASA missions, the Space Infrared Interferometric Telescope (SPIRIT) and the Submillimeter Probe of the Evolution of Cosmic Structure (SPECS)