Surface environment of Phobos and Phobos simulant UTPS

H Miyamoto ,Naoyuki Hirata,Patrick Michel,Hiroki Senshu,Koji Wada,Naomi Murdoch,Olivier S Banouin,Ronald-Louis Ballouz,Katharina A Otto,Tomohiro Usui,Shingo Kameda,Naoki Terada,Nicola Baresi,Yuki Nishio,Ryodo Hemmi,Takafumi Niihara,Takane Imada,Erik Asphaug,Yuta Shimizu,Masatsugu Otsuki,Yojiro Ota ,G Libourel ,Katsuo Mogi ,Tamiko Takemura ,M Grott ,Maria Antonietta Barucci ,Mime Kobayashi ,Hong Peng ,P A Abell ,D T Britt ,Akiko Nakamura ,Hiroshi Kikuchi,Kazunori Ogawa,Naoya Sakatani,Jens Biele,Hideitsu Hino,Sho Sasaki,Shogo Okamoto,Masafumi Tsukamoto,Tomoki Nakamura,Konrad Willner

doi:10.1186/s40623-021-01406-3

Abstract

The Martian Moons eXploration (MMX) mission will study the Martian moons Phobos and Deimos, Mars, and their environments. The mission scenario includes both landing on the surface of Phobos to collect samples and deploying a small rover for in situ observations. Engineering safeties and scientific planning for these operations require appropriate evaluations of the surface environment of Phobos. Thus, the mission team organized the Landing Operation Working Team (LOWT) and Surface Science and Geology Sub-Science Team (SSG-SST), whose view of the Phobos environment is summarized in this paper. While orbital and large-scale characteristics of Phobos are relatively well known, characteristics of the surface regolith, including the particle size-distributions, the packing density, and the mechanical properties, are difficult to constrain. Therefore, we developed several types of simulated soil materials (simulant), such as UTPS-TB (University of Tokyo Phobos Simulant, Tagish Lake based), UTPS-IB (Impact-hypothesis based), and UTPS-S (Simpler version) for engineering and scientific evaluation experiments.

Highlights

Phobos and Deimos, the two moons of Mars, are the target bodies of Japan Aerospace Exploration Agency (JAXA)’s Martian Moons eXploration (MMX) mission, scheduled to be launched in 2024 (Kuramoto et al 2021)
The MMX mothership will land on the surface of Phobos for a few hours, and the mission team must design both the landing and sampling devices appropriately to comply with the surface conditions on Phobos
This paper summarizes our assessment of the surface conditions of Phobos developed by the Landing Operation Working Team (LOWT) and Surface Science and Geology Sub-Science Team (SSG-SST) activities, which provided the necessary engineering constraints to design the MMX mission

Summary

Introduction

Phobos and Deimos, the two moons of Mars, are the target bodies of Japan Aerospace Exploration Agency (JAXA)’s Martian Moons eXploration (MMX) mission, scheduled to be launched in 2024 (Kuramoto et al 2021). Based on these proximity observations, we know that the surface of an asteroid is covered by regolith whose properties can be very different from one object to the depending on a number of factors including the asteroid’s mineralogy and its gravity field (size).

Results

Conclusion