Dr Alesia Herasimenka

This paper analyses the feasibility of a Moon-enabled Sun occultation mission aimed at observing the solar corona. Since the corona is normally obscured by the brightness of the Sun, the proposed concept consists of positioning a spacecraft behind the Moon so that the incident light from the solar disk is blocked. Low-thrust propulsion is considered to assess its suitability for this type of mission. The mission geometry includes lunar flybys to modify the spacecraft orbit, allowing it to pass through prescribed occultation zones. A multi-arc approach is employed to optimize the complete trajectory while accounting for the relevant mission constraints.

The Lunar Volatile and Mineralogy Mapping Orbiter (VMMO) is an ESA 16U CubeSat mission designed to investigate the distribution of water ice and ilmenite near the lunar south pole, supporting future in-situ resource utilisation for sustained lunar exploration. Its primary payload, the Lunar Volatile and Mineralogy Mapper (LVMM), is a multi-wavelength chemical lidar operating at 532 nm, 1064 nm, and 1560 nm in both passive and active modes, enabling observations under varying illumination conditions. Additional payloads include the CLAIRE radiation detector and an experimental GNSS receiver for testing lunar navigation using Galileo spillover and second-lobe signals, as well as future Moonlight constellation signals. The mission comprises three phases: transfer, operational, and disposal. The transfer phase has two possible options: release from a translunar injection trajectory followed by a lunar flyby and low-thrust capture, or a many-revolution low-thrust spiral from low lunar orbit. The spacecraft uses two electrical propulsion thrusters to reach a 41 × 200 km polar frozen orbit with argument of periapsis of 270°, selected to maximise low-altitude coverage of permanently shadowed regions in Faustini, Cabeus, and Shackleton craters. Simulations show satisfactory surface visibility over a two-year science phase. Because of the limited ΔV, a semi-controlled lunar impact, compliant with ESA debris mitigation requirements, was selected as the end-of-life disposal strategy.

The study of the solar corona has important ramifications on the understanding and forecasting of space weather phenomena. Yet, regardless of scientific breakthroughs brought by space-based coronagraphs, access to the lowest layers of the Sun’s atmosphere remains possible mostly during rare and sporadic total solar eclipses on Earth. This paper introduces the preliminary trajectory design analyses of a Moon-Enabled Sun Occultation Mission (MESOM), which capitalizes on synodic resonant orbits in the Sun-Earth-Moon four body problem to enable global and high-quality measurements of the solar corona below 1.02 sun radii once every synodic month (e.g., 29.6 days)

This study investigates the feasibility of a Moon-enabled Sun occultation mission to observe the solar corona, normally obscured by the Sun's brightness. The concept involves positioning a spacecraft behind the Moon to block the incident light coming from the solar disk. Low-thrust propulsion is analyzed to assess its suit-ability for such a mission. The mission geometry includes lunar flybys to modify the orbit, enabling the spacecraft to pass through designated occultation zones. A multi-arc approach is employed to optimize the full trajectory while accounting for mission constraints.

The study of the solar corona has important ramifications on the understanding and forecasting of space weather phenomena. Yet, regardless of scientific breakthroughs brought by space-based coronagraphs, access to the lowest layers of the Sun’s atmosphere remains possible mostly during rare and sporadic total solar eclipses on Earth. This talk introduces the UK-led Moon-Enabled Sun Occultation Mission concept (MESOM), which capitalizes on synodic resonant orbits in the Sun-Earth-Moon four body problem to enable global and high-quality measurements of the inner sun corona below 1.02 sun radii. Our preliminary trade-off analyses show that a mini-satellite platform can reproduce total eclipse conditions in space once every synodic month (e.g., 29.6 days) and for 15 minutes on average, i.e., three times longer than the average eclipse duration on Earth, without image degradation caused by the Earth's atmosphere. With a nominal science operation plan of 2 years, MESOM could collect the equivalent amount of data of roughly 80 eclipses on Earth, making it a once in a life-time opportunity for deepening our understanding of the sun and its atmosphere.