Design of a spaceborne optical aperture synthesis system for high-resolution astronomy

This paper proposes a design for a space borne interferometer with imaging capabilities. Multiple aperture interferometry is a promising technique for high resolution imaging in space. Indeed the use of modular elements based on optical fibers represents an attractive low cost approach compared to very large monolithic mirrors. The proposed instrument is based on the use of independent triplets of telescope linked with optical fibers. For each triplet, only the phase closure of the system is measured. This does not require an accurate cophasing of the apertures and leads to realistic stability and control specifications. The complete instrument is then build by adding the desired number of such triplet modules. The detailed design of one module is described starting at level of the receiving telescopes down to the focal plane where the control of the stability of the Optical Path Differences is performed as well as the scientific observations. The global operation of the system will also be described. We eventually briefly recall the technology validation activities which have shown on ground the feasibility and performance of all components of such a systems as well as its end to end validation.