5:15 PM - 6:30 PM
[PCG10-P03] Geophysical experiments on Phobos proposed for JAXA Mars Moon Exploration mission
Keywords:MMX, Martian moon, Phobos, Planetary exploration, Internal structure
We proposed five scientific instruments for this mission. SEIS: a three-axes short-period seismometer and an active seismic vibration source, SSXT: a penetration probe of several tens cm length with temperature and thermal conductivity sensors, miniRAD: a miniaturized thermal infrared radiometer, a muon detector, and SUMIRE: a mechanical insertion resistance probe of 5 cm length. All these instruments basically aim at investigating the geophysical properties of the surface, sub-surface, and interior of Phobos, and their combined observations can provide integrated models of mechanical and thermal properties of the subsurface which has not been studied so far. The scientific objectives of these instruments are connected to the following mission objectives corresponding to the mission goals above: (a) To obtain indirect information on the Phobos internal structure in order to constrain the origin of Phobos independent of the sample analysis results. (b) To characterize the space environment and the surface features of Phobos, with the intention of comparison with asteroids.
Because the first four of the above scientific instruments require a long observation time at a fixed location, a long-lived landing package (MSM) is also proposed. SUMIRE is planned to be mounted on the feet of the mothership (main lander). Objectives of MSM are providing electric power, command/telemetry interfaces, and an operable environment for the scientific instruments throughout a period of our observations over a Mars year. MSM has the following specifications and functions: (i) Operates independently from the mothership and survives at a fixed point of area. (ii) Controls internal temperature in an operable range of the scientific instruments for their continuous observations. (iii) Provides wired interfaces of telemetry/command and power to the scientific instruments. (iv) Communicates over a radio link with the mothership in orbits and with ground-based stations on the Earth. MSM will be placed on Phobos’ surface during the landing sequence of the main spacecraft, and stay there over its entire lifetime.