Interstellar Mapping and Acceleration Probe (IMAP) Mission Implementation Progress and Challenges

The Interstellar Mapping and Acceleration Probe (IMAP), competitively selected as part of NASA’s Solar Terrestrial Probes program in 2018, is currently preparing to start observatory integration. Unsurprisingly, the mission has experienced numerous challenges resulting in design changes and lessons learned, the two major focuses of this paper. The science motivation for IMAP, including investigations into the acceleration of energetic particles and the interaction of the solar wind with the interstellar medium, has remained unchanged. Similarly, the overall mission architecture has largely remained stable since the publication of "Interstellar Mapping and Acceleration Probe Mission Overview" in 2021 [1]. To complete its science objectives, IMAP relies on ten instruments accommodated on a sun-tracking, spin-stabilized spacecraft, in a L1 Lissajous orbit. The journey to the science orbit begins aboard a Falcon 9, launched from Cape Canaveral Space Force Station in February 2025, and continues along a ~3.6-month cruise that culminates in a day-long maneuver. Through integration, test and operations the spacecraft and payload are operated from separate institutions, the Johns Hopkins Applied Physics Laboratory (JHU/APL) and the Laboratory for Atmospheric and Space Physics (LASP) respectively, in a decoupled operations architecture. The mission relies on the NASA Deep Space Network (DSN) for the majority of its ground support and supports IMAP Active Link for Real Time (I-ALiRT), the constant broadcasting of real-time space-weather data to participating ground stations.IMAP has experienced significant changes across all mission elements. The instruments and spacecraft have experienced the most significant changes including redesigns of an instrument pivot mechanism and the spacecraft structure. Launch vehicle accommodation has also evolved with an updated rideshare configuration featuring the Carruthers Geocorona Observatory and Space Weather Follow On-Lagrange 1 (SWFO-L1). Additional ground support from the Swedish Space Consortium (SSC) network has been baselined to enable earlier initial acquisition. Ground support from European Space Tracking (ESTRACK) network is also being considered in response to competition for DSN time, particularly with the rideshare payloads. IMAP has made a concerted effort to document lessons learned while continuing to progress toward its launch readiness date. Two major challenges that may be applicable to other missions in earlier phases of development, 1) cross-institution collaboration and 2) the use of ‘heritage’, build-to-print hardware, are also discussed.