The NOBEL mission aims to study the thermal and non-thermal escape of major atmospheric components (nitrogen, oxygen, and their isotopes) from the Earth, a magnetized planet. This requires the first-time exploration of the Earth’s entire exosphere as well as the first-time examination of isotope ratios in an extended altitude range, from the upper ionosphere (800 km high) up to the magnetosphere.
The measurement quality should allow connecting the various types of escape from the Earth to the different gravity mass-filtering and chemical reactions on a geological time scale. Since the solar EUV and solar wind conditions during solar maximum at present are comparable to the solar minimum conditions 1-2 billion years ago, the escaping amount and the isotope and N/O ratios should be obtained as a function of external forcing (solar and geomagnetic conditions) to allow a scaling to the past.
To achieve these goals, the ion measurements in this mission should be able to separate nitrogen species (N, N2, N+ and N2+) from oxygen (O, O+), near the exobase, in the exosphere and up in the magnetosphere.
The proposed mission ESA-M5 mission consists of a spinning satellite in a 500 km x 33000 km altitude high-inclination orbit, equipped with in-situ and remote sensing instruments.