Mapping the Edge of Our Solar System

IMAP mission logo. Credit: NASA

The Interstellar Mapping and Acceleration Probe (IMAP), launched in September 2025, is a NASA mission exploring how charged particles from the Sun are energized to form the solar wind and how that wind interacts with interstellar space at the heliosphere’s boundary.

Orbiting upstream of the earth, IMAP will also provide warning of space weather events.

At the heart of the 10 strong instrument suite is Imperial College London’s Magnetometer (MAG) — a precision instrument built to measure the local magnetic field around the IMAP observatory.

 

Launch of the SpaceX Falcon 9 rocket carrying the IMAP spacecraft. Credit: NASA/SpaceX

IMAP’s discoveries will help us understand:

  • Energetic neutral atoms returning from the interactive region of the heliopause towards the Sun.
  • How the solar wind interacts with the interstellar medium
  • How magnetic fields guide and accelerate energetic particles
  • space weather — the powerful solar storms that can disrupt satellites, power grids, and astronauts far from home

By providing real-time space weather data from 1.5 million km upstream of Earth, IMAP acts as an early warning system for our planet — watching the Sun so we can stay protected.

The MAG Instrument

Built by Imperial’s Space Magnetometer Laboratory, MAG is a high-precision instrument that measures the magnetic field around IMAP.
It’s made up of:

  • An electronics box mounted on the spacecraft body
  • Two ultra-sensitive three-axis fluxgate sensors, named MAGo and MAGi, mounted on a 2.5-metre boom to avoid magnetic interference from the spacecraft

Sharing a proud design heritage with the Solar Orbiter mission, MAG is engineered to detect the smallest variations in the solar wind’s magnetic field.

 

IMAP MAG during testing of the MAG boom with MAGo and MAGi installed. The MAG boom is partially deployed. (Credit: NASA/Johns Hopkins APL/Princeton/Ed Whitman)

Facts

  • Launch: September 24, 2025 — Kennedy Space Center, Florida
  • Orbit: Halo orbit around the Sun-Earth L1 point, 1.5 million km upstream of Earth in the solar wind
  • Mission Duration: 1 year
  • Lead Institution (MAG): Imperial College London
  • MAG Science Lead: Prof. Tim Horbury
  • MAG Instrument Manager: Helen O'Brien
  • Funding: UK Space Agency
IMAP MAG team (Dec 2024)

External Links

Princeton IMAP Site | NASA IMAP Site | UK Space Agency

Find out more

Instrument Development

The IMAG Magnetometer takes heritage from the Solar Orbiter MAG instrument, with interfaces updated to match the IMAP spacecraft.

Useful Links

IMAP Links: