Systems Engineering Approach for the SPHEREx Telescope Mission

Abstract The Spectro‐Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx) was selected in 2019 as a NASA Astrophysics Medium Class Explorer mission to perform the first infrared all‐sky spectral survey. The mission consists of a single wide field of view telescope mounted on top of a Ball Configurable Platform (BCP) spacecraft bus. Over the course of its two‐year mission, the SPHEREx observatory will perform four all‐sky surveys and provide spectroscopic measurements of hundreds of millions of galaxies and a diversity of astronomical phenomena. SPHEREx is currently in phase C, post‐Critical Design Review (CDR) and is in the process of building and testing hardware in preparation for observatory Assembly, Test, and Integration (AI&T) in early 2024. The observatory is expected to launch on a Falcon 9 rocket no earlier than February 2025. Project level systems engineering support is provided by the Jet Propulsion Laboratory (JPL) and oversees the technical development of the observatory and its ground operations. Systems engineers are staffed throughout all the systems and act as a key interface between the mission's many partners. This paper focuses on the systems engineering approach for the SPHEREx mission including its architecture, verification and validation methodology, and its risk and resource management approach.