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The VIrtual Super Optics Reconfigurable Swarm (VISORS) mission is a distributed telescope consisting of two 6U CubeSats separated by forty meters that will obtain high-resolution images of active solar regions in the extreme ultraviolet spectrum. This mission is challenging because the CubeSats must autonomously control their relative motion with unprecedented accuracy while operating in close proximity. This paper presents three contributions that enable the VISORS mission to meet its challenging requirements. First, passively safe absolute and relative orbit designs for distributed telescopes that provide regular periods of alignment with inertial targets are developed using relative eccentricity/inclination vector separation. Second, a guidance, navigation, and control system design is proposed to meet the demanding relative motion control requirements. Third, a concept of operations is proposed that minimizes mission operations load when the formation is not actively performing observations. This concept of operations includes a safety plan to address on-orbit anomalies. The performance of the guidance, navigation, and control system is validated through Monte Carlo simulations including all significant error sources and operational constraints. These simulations show that the mission requirements are met with margin, providing a preliminary demonstration of the feasibility of accurate autonomous formation control with CubeSats. 

This paper presents the preliminary system design of the Virtual Super-resolution Optics with Reconfigurable Swarms (VISORS) mission, a multi-CubeSat distributed telescope which will image the solar corona to investigate the existence of underlying energy release mechanisms. VISORS was conceived in the National Science Foundation (NSF) CubeSat Innovations Ideas Lab Workshop held in 2019 to address NSF science goals with innovative technologies. This mission will gather imagery that directly pertains to theories of coronal heating. In the paper, novel technologies are described that enable the VISORS mission to meet its challenging requirements and achieve the mission and science goals. The VISORS formation is composed of two 6U CubeSats that fly 40 meters apart during science imaging as a distributed space telescope, with the lead spacecraft containing the optics and the trailing spacecraft containing the detector. An orbit maneuver planner utilizes GNSS carrier-phase measurements to provide a high-precision navigation solution, and a series of ceramic antenna arrays employ a novel 5.8 GHz inter-satellite crosslink. A 3 degrees-of-freedom (3DOF) propulsion system provides the capability for formation adjustments and active collision avoidance. The remaining spacecraft functions are handled by a spacecraft bus supplied by a commercial vendor, and the system integration is conducted by the VISORS mission team. Careful analysis of the system design and concept of operations led to the development of a safety plan which significantly reduces the risk of collision in a large subset of off-nominal scenarios. With a completed preliminary design review in Q4 2020 and a projected launch date in late 2023, this collaboration among 10 different universities, NASA, and a commercial partner is an upcoming mission that will demonstrate a new assembly of highly equipped CubeSats and their ability to conduct a state-of-the-art science mission in a cost and time effective manner.