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Published March 1, 2026 | Version Published
Journal Article Open

The SPHEREx Satellite Mission

Creators

  • 1. ROR icon California Institute of Technology
  • 2. ROR icon Jet Propulsion Lab
  • 3. ROR icon University of Arizona
  • 4. ROR icon Infrared Processing and Analysis Center
  • 5. ROR icon Harvard-Smithsonian Center for Astrophysics
  • 6. ROR icon Korea Astronomy and Space Science Institute
  • 7. ROR icon Argonne National Laboratory
  • 8. ROR icon Arizona State University
  • 9. ROR icon Institute of Astronomy and Astrophysics, Academia Sinica
  • 10. ROR icon Institut de Recherche sur les Lois Fondamentales de l'Univers
  • 11. ROR icon University of California, Irvine
  • 12. ROR icon Rochester Institute of Technology
  • 13. ROR icon University of California, Berkeley
  • 14. BAE Systems, Inc., Space and Mission Systems, 1600 Commerce Street, Boulder, CO 80301, USA
  • 15. ROR icon Seoul National University
  • 16. ROR icon Yonsei University
  • 17. ROR icon Sejong University
  • 18. ROR icon Johns Hopkins University
  • 19. ROR icon Johns Hopkins University Applied Physics Laboratory
  • 20. ROR icon Ho Chi Minh City University of Science
  • 21. ROR icon University of Chicago

Abstract

Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx), a NASA Explorer satellite launched on 2025 March 11, is carrying out the first all-sky near-infrared spectral survey. The satellite observes in 102 spectral bands from 0.75 to 5.0 μm with a resolving power ranging from λ/Δλ = 35–130 in 6."2 pixels. The observatory obtains a 5σ depth of 19.5–19.9 AB mag for 0.75 < λ < 3.8 μm with λ/Δλ ∼ 40 and 17.8–18.8 AB mag for 3.8 < λ < 5.0 μm with λ/Δλ ∼ 120 after mapping the full sky four times over two years. Scientifically, SPHEREx will produce a large galaxy redshift survey over the full sky to constrain the amplitude of inflationary non-Gaussianity. The observations will produce two deep spectral maps near the ecliptic poles that use intensity mapping to probe the evolution of galaxies over cosmic history. By mapping the depth of infrared absorption features over the Galactic plane, SPHEREx will comprehensively survey the abundance and composition of water and other biogenic ice species in the interstellar medium. The project will release initial data rapidly in the form of spectral images, and specialized data products over the life of the mission as the surveys proceed. The science team will also produce spectral catalogs of planet-bearing and low-mass stars, solar system objects, and galaxy clusters three years after launch. We describe the design of the instrument and spacecraft, which flow from the core science requirements. Finally, we present an initial evaluation of the satellite’s in-flight performance and key characteristics.

Copyright and License

© 2026. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

Acknowledgement

This publication makes use of data products from the Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer (SPHEREx), which is a joint project of the Jet Propulsion Laboratory and the California Institute of Technology in the U.S., funded by the National Aeronautics and Space Administration, and the Korea Astronomy and Space Science Institute (KASI) in South Korea. The Korean contribution to SPHEREx was supported by KASI under the Korea AeroSpace Administration (KASA).

Part of the research was carried out at the Jet Propulsion Laboratory and the California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). Work at Argonne National Laboratory was supported by the U.S. Department of Energy, Office of High Energy Physics. Argonne, a U.S. Department of Energy Office of Science Laboratory, is operated by UChicago Argonne LLC under contract no. DE-AC02-06CH11357.

The project thanks the many people who helped develop and implement hardware for the mission, including but not limited to staff at NASA, JPL, BAE, IPAC, IRSA, KASI, SpaceX, VSFB, Caltech, Viavi, Applied Aerospace Structures, UC Berkeley SSL, and Teledyne.

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Additional details

Related works

Is new version of
Discussion Paper: arXiv:2511.02985 (arXiv)

Funding

National Aeronautics and Space Administration
80NM0018D0004
United States Department of Energy
DE-AC02-06CH11357

Dates

Submitted
2025-11-01
Accepted
2025-12-09
Available
2026-02-27
Published

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Caltech groups
Infrared Processing and Analysis Center (IPAC) , Astronomy Department , Physics Department , Division of Physics, Mathematics and Astronomy (PMA)
Publication Status
Published