Lunar Neutrals Telescope for Turkish Lunar Mission

The solar wind, a constant stream of mainly protons and alpha particles originating from the sun, constantly precipitates on the surfaces of atmosphere-less bodies like the Moon. The process results in backscattered and sputtered energetic neutral atoms that can be measured from orbit.

This makes remote sensing of surface properties and near-surface plasma conditions possible, which are inaccessible on a global scale by other means.With the successful energetic neutral atom observations at the Moon by the Indian Chandrayaan-1 spacecraft, the Swedish Institute of Space Physics (IRF) has opened a new field in remote sensing of the solar wind - surface interaction and has been leading the European group in this subject.

The fact that similar measurements are planned using IRF built instrumentations on Mercury by ESA/JAXA’s BepiColombo and on Jovian moons by ESA’S JUICE mission shows uniqueness and power of this technique.In collaboration with the Space Technologies Research Institute of the Scientific and Technological Research Council of Turkey (TUBITAK UZAY), IRF successfully obtained a flight opportunity to send our instrument, Lunar Neutrals Telescope (LNT), to an orbit around the Moon by Turkish Lunar Mission (TLM).

The mission was already approved by the Turkish Space Agency in 2021. The TLM will launch in mid 2024.

Following 1 month on Earth transfer orbit, the spacecraft will reach the Moon and start the orbit acquisition phase lasting for 2-4 weeks. After that, the spacecraft will be placed on a 100 km circular polar orbit for 3 months for scientific observations. The mission ends with the controllable hard landing (impact) in the polar region.

The main goal of the mission is to develop technologies for the lunar and planetary exploration.The LNT is an energetic neutral particle instrument specially designed to answer some fundamental scientific questions of the Moon.

There are three major scientific objectives defined for LNT: (A) To search for volatile-rich areas on the Moon’s surface and make the volatile map including permanently shadowed regions, (B) to investigate the structure (shape) of mini-magnetosphere created by lunar magnetic anomalies and its response to the solar wind, and (C) to investigate the formation and maintenance processes of the lunar exosphere.The Design of the LNT is based on the successful predecessor CENA/SARA sensor on Chandrayaan-1 and is updated to achieve unprecedentedly high angular resolution, which is approximately factor of 7 higher than the predecessor.

The LNT has been originally developed for the Russian lunar orbiter (Luna-26), but IRF had to decide on terminating the participation in the project due to various constraints. Therefore, the design and prototyping phases have been already completed. Even Electrical Model, Structural Model and Thermal Model have been built to demonstrate maturity of the design.

This makes it possible to shorten the lead time of the flight model delivery, which perfectly matches the timeline of the TLM. The participation in the TLM is a recovery project to utilize developments made for Luna-26.

This first collaboration between Swedish and Turkish space communities will open up future collaborating opportunities.We apply for the funding for travels to Turkey for hardware deliveries, testing, instrument commissioning and instrument operation and components for the flight hardware as well as external consultancy for the flight hardware testing.

One scientific conference travel and a publication cost for an instrument paper are also included, but scientific data analysis is not within the scope of this application.