OSIRIS-REx is an acronym that incorporates the mission’s major concepts and goals.  When the mission was first being formed, then-Deputy Principal Investigator Dante Lauretta was working to define the science investigation for an asteroid sample return mission.  In writing out a list of the big ideas that the science plan would be based on, Dr. Lauretta realized that they spelled out OSIRIS.


  • O – Origins

    Return and analyze a sample of a pristine carbon-rich asteroid to study the nature, history, and distribution of its minerals and organic material.

  • SI – Spectral Interpretation

    Define the global properties of a primitive carbon-rich asteroid to allow for direct comparison with existing ground-based telescopic data for all asteroids.

  • RI – Resource Identification

    Map the global properties, chemistry, mineralogy of a primitive carbon-rich asteroid to define its geologic and dynamic history and provide context for the returned sample.

  • S – Security

    Measure the Yarkovsky Effect* on a potentially hazardous asteroid and learn which asteroid properties contribute to this effect.
    *A force caused by the emission of heat from a rotating asteroid that can change its orbit over time

  • REx – Regolith Explorer

    Document the texture, morphology, geochemistry, and spectral properties of the regolith (surface material) at the sampling site.


The mythology of the Egyptian god Osiris loosely parallels the OSIRIS-REx mission. Osiris, in his original form, was believed to have spread an understanding of agriculture throughout the Nile Delta, hence bringing life to the ancient world. Likewise, OSIRIS-REx seeks to return samples of an asteroid that may contain organics that led to the origin of life on Earth.  Osiris also had a dual role as the god of the Underworld, which mirrors the destruction that large asteroid impacts have created.