Redundancy in the Science Implementation of NASA's Lucy Mission to the Trojan Asteroids

Lucy is NASA's 13th Discovery-class mission and it will be the first mission to the Jupiter Trojan asteroids. Over the course of 12 years, the mission will encounter 7 Trojan asteroids in a series of 5 flybys. The time critical nature of the asteroid flybys coupled with the long-duration mission drive design considerations for redundancy in the implementation of the mission. This paper focusses on the redundancy in the science planning and instrument designs. A risk-based assesment informed decisions about instrument selection, instrument design, and science timeline considerations. The mission carries three scientific instruments, a high resolution panchromatic imager, a combination panchromatic/color visible imager and near-infrared spectral imager, and a thermal infrared spectrometer. Additionally, a component of the guidance and control subsystem, the terminal tracking cameras, will contribute to the scientific data collected on the mission. Redundancy in the science instruments includes redundant electronics and data storage separate from the data storage on the spacecraft. The science observation sequence also has redundancy built into it. An example of this is backup observations to provide more than one opportunity to accomplish critical science objectives. These design considerations are achievable in a Discovery-class mission and reduce risk during Lucy's 12-year operations phase to achieve the mission's science objectives.