The Upcoming ESA Scout NanoMagSat Mission, a Nanosatellite Constellation to Further Improve Geomagnetic Field and Ionospheric Environment Monitoring and Modeling

Geomagnetic field and ionospheric environment monitoring is presently achieved with huge success by the three satellites of the Swarm Earth Explorer ESA constellation launched in November 2013. Maintaining and improving observations beyond the lifetime of Swarm is critical for both science investigations and advanced applications. NanoMagSat aims at fulfilling this goal. This much cheaper mission is currently in Phase B within the context of the ESA Scout program. It will deploy and operate a new Low-Earth orbiting constellation of three identical 16U nanosatellites, using two inclined (~ 60°) and one polar orbits at an initial altitude of 545 km, to complement and take over the Swarm mission. The mission is planned to start deploying end of 2027, for a minimum of three years of full constellation operation between 2028 and 2031.

This constellation is designed to cover all local times (LT) at all latitudes, with special emphasis on latitudes between 60°N and 60°S, where all LT will be visited within about a month, much faster than is currently achieved by the Swarm constellation. Each satellite will carry an advanced Miniaturized Absolute scalar and self-calibrated vector Magnetometer (MAM) with star trackers (STR) collocated on an ultra-stable optical bench at the tip of a deployable boom, a new compact High Frequency Magnetometer (HFM) (at mid-boom), a multi-Needle Langmuir Probe (m-NLP) and dual frequency GNSS receivers (all on the satellite body). This payload suite will acquire high-precision/resolution oriented absolute vector magnetic data at 1 Hz, very low noise scalar and vector magnetic field data at 2 kHz, electron density data at 2 kHz, and electron temperature data at 1 Hz. GNSS receivers will also allow top-side TEC and ionospheric radio-occultation profiles to be recovered.

In this presentation, the main science goals of the mission will first be introduced and the rationale for the choice of the payload and constellation design next explained. The various data products currently planned to be produced will also be described. Special emphasis will be put on the innovative aspects of the mission with respect to Swarm and other previous missions. Finally, the benefit of relying on such nanosatellite constellations for maintaining long-term observations of the magnetic field and ionospheric environment, to complement ground-based observations will also be discussed.