Capabilities and Geometry of the VLBI Mode in the Millimetron Mission

Very long baseline interferometry (VLBI) is a unique technique allowing observations of the most compact astronomical objects with high angular resolution. In this study, we demonstrate the capabilities of the Millimetron VLBI mode regarding the tasks of two-dimensional imaging of black hole shadows and observing compact structures around them. Attention is paid not only to the sensitivity and frequency configuration of the space–ground interferometer, but also to its geometry, namely possible orbital configurations of the Millimetron observatory and their observational capabilities.