Interstellar Mapping and Acceleration Probe

The Interstellar Mapping and Acceleration Probe (IMAP) is a heliophysics mission that simultaneously investigates two important and coupled science topics in the heliosphere: the acceleration of energetic particles and interaction of the solar wind with the local interstellar medium. These science topics are coupled because particles accelerated in the inner heliosphere play crucial roles in the outer heliospheric interaction. In 2018, NASA selected a team led by David J. McComas of Princeton University to implement the mission. IMAP is a Sun-tracking spin-stabilized satellite in orbit about the Sun–Earth L1 Lagrange point with a science payload of ten instruments. IMAP also continuously broadcasts real-time in-situ data that can be used for space weather prediction. It is the fifth mission selected in the Solar Terrestrial Probes program, after TIMED, Hinode, STEREO and MMS. IMAP launched on 24 September 2025.