Space VLBI-Exploring The Potential of Hybrid Orbit Configurations

Space-Based Very Long Baseline Interferometry (SVLBI) offers unprecedented resolution and sensitivity in radio astronomy by deploying radio telescopes in space. However, designing an optimal satellite constellation for SVLBI is challenging due to the need for comprehensive \((u,v)\) coverage. This is the first paper in a series that examines different orbital configurations to identify the most suitable for SVLBI applications.Hybrid constellations, combining satellites in different orbits were found to be superior to single-orbit configurations. Specifically, three hybrid configurations demonstrated exceptional performance: a four-satellite setup with two satellites in Medium Earth Orbit (MEO) and two in Low Earth Orbit (LEO); a five-satellite configuration with three satellites in MEO and two in LEO; and a five-satellite constellation comprising one satellite in High Earth Orbit (HEO), two in MEO, and two in LEO.These configurations were evaluated based on their $(u,v)$ coverage, point spread function, and simulations of point and extended sources. In the sequel paper, we will further explore the resolution, imaging fidelity, and dynamic range obtained using this optimal configuration.