Projects of optical space-based stellar interferometers

We describe projects of space-based stellar interferometers developed in different countries as astronomical multipurpose tools of the next generation after the Hubble space telescope (HST). The short-baseline systems (baseline length of about 2 m) are designed for astrometry with an accuracy of 10 mu as rms. The long-baseline systems (baseline length >5 m) are studied for image formation in the aperture synthesis mode of operation with a resolution of about 1 mas. Fundamental technologies of this type are based on the use of active optics and smart-design. (C) 1999 The Optical Society of America. [S1070-9762(99)00102-5].