NASA's Interstellar Mapping and Acceleration Probe (IMAP) has reached the first Sun-Earth Lagrange point (L1) following a three-and-a-half-month journey. The spacecraft is positioned to map the heliosphere's outermost boundary, which shields the solar system from galactic radiation.
IMAP launched on September 24, 2025, aboard a SpaceX Falcon 9 rocket from Kennedy Space Center, traveling approximately 1 million miles toward the Sun. The L1 location provides an uninterrupted view of incoming solar particles and interstellar material.
On January 10, 2026, engineers at the Mission Operations Center in Laurel, Maryland, confirmed IMAP successfully completed orbital maneuvers to achieve a stable orbit around L1. This gravitationally balanced point between Earth and Sun offers an ideal line of sight for heliophysics missions, according to the Johns Hopkins Applied Physics Laboratory.
During its transit, IMAP's ten scientific instruments began recording data, collecting measurements of solar wind, energetic neutral atoms, and interstellar dust. Full operations are scheduled to commence on February 1.
IMAP's payload is designed to sample particles from both the solar wind and the local interstellar medium. These measurements aim to create a three-dimensional, time-varying map of the heliosphere. David McComas, Princeton University professor and principal investigator, stated that this boundary is crucial for understanding how the solar system is shielded from cosmic radiation.
One of the probe's main targets is energetic neutral atoms, which form at the heliosphere's edge and travel inward, enabling researchers to remotely image this otherwise unreachable region of space.
Beyond its scientific objectives, IMAP will support short-term operational needs through the IMAP Active Link for Real-Time (i-alirt) system. This system will enhance the accuracy and timeliness of space weather forecasts, which are essential for protecting communications systems, power grids, and space missions from solar storms.
The Johns Hopkins Applied Physics Laboratory (APL) developed and integrated the spacecraft and its systems, leading the mission design and testing.