The operational work of the Interplanetary Solar Stereoscopic Observatory (ISSO) may continue for 11 years. The ISSO Project is designed to insert two spacecraft (SC) into Lagrangian triangular libration points of the “Sun + barycenter (the Earth + the Moon)” system. The Project scientific program consists of two sets of experiments related to solar physics and to dynamical astronomy, respectively.
Various options of the astronomical observation program are possible. We discuss the option where the stereoscopic mode is applied to the direct triangulation observations of the solar system objects with respect to the ICRS coordinate frame.
The stereoscopic mode with the baseline equal to appears to be suitable for receiving the three-dimensional (3-D) measurement series for planets during the ISSO’s lifetime. Extended investigation of the planetary aberration based on the observations of major and minor planets, the direct distance determinations for minor planets and Kuiper’s belt objects, and the new set of star parallaxes may be used for constructing a new fundamental ephemeris and establishing an alternative scale of stellar distances. The accuracy of the angular measurements is expected to attain the milliarcsecond level.