Interstellar Mapping And Acceleration Probe: The NASA IMAP Mission

Abstract

NASA's Interstellar Mapping and Acceleration Probe (IMAP) mission provides extensive and well-coordinated new observations of the inner and outer heliosphere and scientific closure on two of the most important topics in Heliophysics: 1) the acceleration of charged particles and 2) the interaction of the solar wind with the local interstellar medium. These topics are intimately coupled because particles accelerated in the inner heliosphere propagate outward through the solar wind and mediate its interaction with the very local interstellar medium (VLISM). The IMAP mission is designed to address these topics, provide extensive new real-time measurements critical to Space Weather observations and predictions, and much more. IMAP's ten instruments are mounted on a simple, spinning spacecraft that orbits about the first Sun-Earth Lagrange point, L1, and repoints its Sun-facing solar arrays and spin axis toward the Sun each day. The instruments provide complete and synergistic observations that examine particle energization processes at 1 au while simultaneously probing the global heliospheric interaction with the VLISM. The 1 au in-situ observations include solar wind electrons and ions from solar wind through suprathermal energies, pickup and energetic ions, as well as the interplanetary magnetic field. IMAP provides Energetic Neutral Atom (ENA) global imaging of the outer heliosphere via ENAs from tens of eV up through hundreds of keV, as well as observations of interstellar neutral atoms traversing the heliosphere. IMAP also directly measures interstellar dust that enters the heliosphere and the solar-wind-modulated ultraviolet glow. This paper provides the mission overview for the full IMAP mission, acts as a roadmap to the other papers in this IMAP collection and provides the citable reference for the overall IMAP mission going forward. Supplementary Information: The online version contains supplementary material available at 10.1007/s11214-025-01224-z.