SIMURIS: a High Resolution Solar Physics Interferometric Mission in Answer to the Chromospheric and Coronal Heating Problem

The SIMURIS Mission, dedicated to ultrahigh resolution imaging and spectroscopy of the solar atmosphere from the convection zone to the high corona, has two major instruments: the Solar Ultraviolet Network (SUN) which is a 4 telescopes interferometer capable of 10 km spatial resolution on the Sun, and the Imaging Fourier Transform Spectrometer (IFTS) which provides multispectral instantaneous 2D velocity fields of the solar atmosphere. SIMURIS was proposed to ESA in November 1989, and accepted for an Assessment Study in the context of the Space Station in February 1990. The main scientific objectives are outlined and the model payload is briefly described. In particular, the interest of high angular resolution to understand the coronal loop structure is illustrated on selected examples since current observations are unable to distinguish in between different dissipation/heating theories such as current built up and resistive instabilities, current built up in singular layers and reconnection, or resonant MHD wave excitation and dissipation.