JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25EDG20166

Subject Category: Research and Development

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• Responsible Representative: Taro Shimizu, Research and Development Directorate, Research Unit III
• Contact Information: Hiroaki Amakawa , Research Unit III, Research and Development Directorate. Japan Aerospace Exploration Agency(amakawa.hiroaki@jaxa.jp)
• Members: Hiroaki Amakawa, Masaru Kusano, Kaname Kawatsu, Kugo Okada

Abstract

In reusable rockets and probe landers, landing is a crucial part of the mission, and the success of the landing determines whether the mission is achieved. While responding to disturbances and environmental changes such as wind and terrain at the landing site during the mission, autonomous and safe landing is required. Focusing on reusable rockets and probe landers, we aim to acquire composite physical modeling and simulation technologies to evaluate the feasibility of landing (precision landing/landing stability) during the early design stages, contributing to the realization of landing systems and ensuring mission success.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

All JAXA employee can use JSS quickly and easily without any complicated procedures.

The system can be connected within the JAXA intranet, so there is little risk of information leakage.

Quick access to extensive support on how to use the system.

The ability to perform numerous Monte Carlo simulations in a short time by utilizing large computational resources.

Achievements of the Year

In the Martian Moons eXploration (MMX) mission, it is necessary to determine a landing site for the sample‑return target, Phobos, within a short timeframe based on detailed observations acquired from orbit. To achieve this, a system is required that can rapidly perform parameter studies accounting for disturbances and uncertainties, and quantitatively evaluate the landing success probability for each candidate site.

In this study, we developed a landing simulation model and established an efficient execution framework, enabling a large number of simulations to be conducted. Specifically, we exported C‑code from the SimulationX solver using the Modelica language, built the code on the JSS3 TOKI‑RURI supercomputer, and implemented a batch‑job mechanism to run landing simulations in parallel. Using this system, we executed 441 simulation cases in 480 seconds on JSS3 TOKI‑RURI, demonstrating the feasibility of future large‑scale Monte Carlo simulations involving hundreds of thousands of cases.

Fig.1: Model of landing simulation

Fig.2: Example of simulation result

Publications

- Oral Presentations

1) Hiroaki Amakawa, Kaname Kawatsu, Masatsugu Otsuki, Mitsuhisa Baba, "Utilization of a Reduced Order Landing Dynamics Model towards Operation Decision Making for Martian Moons eXploration (MMX)," The 35th ISTS. International Symposium on Space Technology and Science, 17th July, 2025.

Usage of JSS

Computational Information

• Process Parallelization Methods: N/A
• Thread Parallelization Methods: N/A
• Number of Processes: 1
• Elapsed Time per Case: 480 Second(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.00

Details

Please refer to System Configuration of JSS3 for the system configuration and major specifications of JSS3.

*1: Fraction of Usage in Total Resources: Weighted average of three resource types (Computing, File System, and Archiver).

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.

ISV Software Licenses Used

*2: Fraction of Usage：Percentage of usage relative to each resource used in one year.

JAXA Supercomputer System Annual Report February 2025-January 2026