Spherex: Nasa'S Near-Infrared Spectrophotometric All-Sky Survey

SPHEREx, the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and ices Explorer, is a NASA MIDEX mission planned for launch in 2024. SPHEREx will carry out the first all-sky spectral survey at wavelengths between 0.75 mu m and 5 mu m with spectral resolving power similar to 40 between 0.75 and 3.8 mu m and similar to 120 between 3.8 and 5 mu m At the end of its two-year mission, SPHEREx will provide 0.75-to-5 mu m spectra of each 6.'' 2x6.'' 2 pixel on the sky -14 billion spectra in all. This paper updates an earlier description of SPHEREx presenting changes made during the mission's Preliminary Design Phase, including a discussion of instrument integration and test flow and a summary of the data processing, analysis, and distribution plans.