NASA’s IMAP Mission to Unlock Secrets of the Interstellar Boundary in 2025

NASA’s Interstellar Mapping and Acceleration Probe (IMAP) is scheduled to launch on 24 September 2025, marking a major step forward in our understanding of the heliosphere—the giant bubble of particles and magnetic fields created by the Sun that surrounds our solar system.

Equipped with precision thrusters from L3Harris, the spacecraft will travel to Lagrange Point 1 (L1), located about 1.5 million kilometers from Earth. From this vantage point, IMAP will study the solar wind and its complex interaction with interstellar material, helping scientists learn more about how particles move between the Sun and the galaxy beyond.

Advanced Propulsion from L3Harris

The propulsion system, designed and integrated at L3Harris’ Redmond, Washington facility, is essential for IMAP’s journey and operations. It includes:

• Three propellant tanks

• Service and latch valves

• Filters and transducers

• Temperature sensors and heaters

• 12 MR-111G monopropellant rocket engines

These thrusters will provide attitude control, orbit insertion, spin adjustments, and corrective maneuvers throughout the mission. “Our thrusters enable IMAP’s attitude control system to steer the spacecraft, perform orbit insertion, adjust its spin rate and perform corrective maneuvers as needed to maintain its orbit,” explained Chris Sebastian, lead program engineer at L3Harris.

Scientific Goals of IMAP

IMAP carries 10 scientific instruments to investigate:

• How solar particles are accelerated to high energies

• How the solar wind interacts with interstellar space

• The processes at the boundary of the heliosphere, where the influence of the Sun gives way to the galactic environment

The mission is led by Professor David J. McComas of Princeton University, with more than 27 partner institutions worldwide contributing. The Johns Hopkins Applied Physics Laboratory (APL) is responsible for building and operating the spacecraft under NASA’s Heliophysics Division.

Broader Significance

The IMAP mission builds on the legacy of past heliophysics missions such as Voyager, IBEX (Interstellar Boundary Explorer), and Parker Solar Probe. While Voyager provided the first direct data from beyond the heliosphere, and IBEX mapped energetic neutral atoms from its boundary, IMAP will combine advanced instruments and high-resolution imaging to fill critical gaps in our knowledge.

By answering key questions about space radiation, cosmic rays, and the shielding role of the heliosphere, IMAP’s data will not only enhance our scientific understanding but also provide insights important for future deep-space exploration and astronaut safety.

As Matt Carollo of L3Harris put it: “Knowing that the propulsion system our team designed, built and installed on the IMAP spacecraft will enable researchers to expand our knowledge of our galactic neighborhood is very rewarding.”