Steps toward hypertelescopes on Earth and in space

For imaging faint and complex sources at high angular resolution, hypertelescopes (direct-imaging many-aperture interferometers using a densified pupil) gain sensitivity with respect to few-aperture interferometers and to Fizeau interferometers. Steps are taken to expand the Carlina-Proto technical prototype built at Observatoire de Haute-Provence, 18m in aperture size, and to define a larger (100-200m) Carlina-Science version, incorporating 100 or more small apertures. Following initial observing by Speckle Interferometry, adaptive co-pistoning is expected to become available, using "Dispersed Speckle" piston sensing oil bright stars, and a modified Laser Guide Star on faint (mv > 25) fields. "Extremely Large Hypertelescope" versions of such instruments, with aperture size beyond a kilometer, are considered for deep-field imaging on cosmological sources. These can be interferometrically coupled with ELTs, or arrays of telescopes, at sites such as the Macon range (Andes) considered by ESO for its E-ELT. Space versions are proposed to ESA and NASA.