LICIACube: Mission Outcomes of Historic Asteroid Fly-By Performed by a CubeSat

This paper presents a comprehensive analysis of the Italian Space Agency's (ASI) Light Italian CubeSat for Imaging of Asteroids (LICIACube) and its significant role in NASA's Double Asteroid Redirection Test (DART) mission. LICIACube, developed and operated by Argotec, successfully completed the first-ever asteroid fly-by performed by a CubeSat, documenting the effects of DART intentional impact with Dimorphos, the secondary body of the 65803 Didymos asteroid system. During the fly-by, in roughly 15 minutes, LICIACube captured more than 600 pictures of the asteroids and the plume ejecta caused by the impact. The CubeSat embedded real-time hardware-accelerated imaging capabilities, combined with its Autonomous Attitude Control System, played a crucial role in achieving precise tracking and imaging of the asteroids.To achieve the mission objectives, LICIACube simultaneously operated its two optical payloads for tracking and scientific purposes. The primary panchromatic camera, LICIACube Explorer Imaging for Asteroid (LEIA), was implemented for rapid feedback to the satellite Autonomous Attitude Control System, ensuring accurate pointing towards the target. LEIA tracked the main body, Didymos, during the initial phases of the fly-by and switched to Dimorphos in the vicinity of the closest approach, which occurred at a distance of approximately 56 km with a relative speed of 6.1 km/s. This seamless transition allowed for comprehensive imaging of both asteroids during the approximately 15-minute-long fly-by. Additionally, LICIACube secondary payload, the RGB camera known as LICIACube Unit Key Explorer (LUKE), facilitated the capture of wide-angle pictures of DART impact with the asteroid. LUKE achieved a maximum image acquisition rate of three pictures per second, providing valuable data for understanding the plume ejecta dynamics and the asteroid composition. The Autonomous Attitude Control and Navigation System of LICIACube faced significant challenges while operating under a very uncertain environment, due to the high fly-by speed and the narrow field of view of the cameras. To ensure accurate tracking of the asteroid, the system was required to maintain a pointing accuracy error lower than 1.4 degrees and handle a peak angular velocity of approximately 7 deg/s to keep the asteroid within the payload's Field of View.The paper introduces LICIACube CubeSat System within DART mission context, discusses Argotec's all-in-house platform design, and highlights the capabilities of the real-time hardware-accelerated imaging system alongside the effectiveness of the Autonomous Attitude Control System. Moreover, in-flight performances, deep space operations and mission results are presented, together with the most relevant flight data and sensational pictures captured at the closest approach with Dimorphos. In conclusion, LICIACube achievements contribute to the advancement of autonomous navigation and imaging technologies, as well as flight operations of CubeSats in deep space, and pave the way for a broader utilization of CubeSats for innovative space exploration concepts and mighty research endeavors.