Investigation of the universe by probing the electromagnetic spectrum at wavelengths from approximately 0.3 to 1.0 millimeter: the submillimeter waveband. This waveband is bounded at longer wavelengths by the millimeter waveband (1– 10 mm), and at shorter wavelengths by the far-infrared waveband (20–300 micrometers). Obtaining an accurate view of the processes going on in stars and galaxies requires observations at a range of different wavelengths, with each available window providing complementary information. Astronomical objects with temperatures between about 10 kelvins and several hundred kelvins, typically in the interstellar medium of galaxies, emit radiation strongly in the submillimeter waveband.