A revolution similar to that brought by CCDs to visible astronomy is still ahead in IR and submillimeter astronomy. There is certainly no wavelength range which has seen such advances in technology: large-scale detector arrays, new designs for cooling in space, and lightweight mirror technologies. Observations in the FIR/Submm range should provide answers to such fundamental questions as: What is the spectrum of the primordial fluctuations? How do primeval galaxies look? What are the first stages of star formation? Most of the international space missions that have been triggered by these questions are presented in detail here. Technological issues raised by these missions are reviewed, as are the most recent achievements in cooling and detector technologies.