Study on spacecraft dynamics

JAXA Supercomputer System Annual Report February 2025-January 2026

Report Number: R25ECWU24

Subject Category: Cooperative Graduate School System

Responsible Representative: Study on spacecraft dynamics
Contact Information: Yusuke Maru(maru.yusuke@jaxa.jp)
Members: Hiroto Aoyagi, Yusuke Maru, Ami Mizumura, Ryota Miyajima, Kazuma Matsumoto, Yuma Miki, Takumi Ohno, Kiwame Sakai, Keisuke Takahashi, Daiki Watanabe, Tsubasa Watabe, Maiko Yamakawa, Hibiki Yamaguchi

Abstract

Specifically, we performed (1) an evaluation of the interference between the thruster jet and the surface of a celestial body when a lander lands on the celestial body, and (2) an analysis of the flow characteristics of an electric pump for supplying propellant to a spacecraft.

Reference URL

N/A

Reasons and benefits of using JAXA Supercomputer System

Each of these themes is being carried out in a complementary manner with experiments, and by using JSS3, analyses can be performed extremely quickly, making it possible to carry out numerical analysis that is effective in setting experimental conditions and understanding experimental results.

Achievements of the Year

(1) We conducted an evaluation of the interference between the thruster jet and the surface of a celestial body during the landing of a spacecraft. Figure 1 shows the analysis results of the thruster jet flow (Mach number contours) for an assumed shape of the celestial body.

(2) We performed a flow-field analysis of a cascade pump used as an electric pump for supplying propellant to spacecraft. This year, we focused particularly on its cavitation characteristics. Figure 2 presents an example of the analysis results of the flow field.

Fig.1: Thruster jet flow analysis and experimental observations

Fig.2: Behavior of cavitation occurring in a cascade pump

Publications

N/A

Usage of JSS

Computational Information

Process Parallelization Methods: MPI
Thread Parallelization Methods: OpenMP
Number of Processes: 256
Elapsed Time per Case: 8.3 Hour(s)

JSS3 Resources Used

Fraction of Usage in Total Resources*1(%): 0.19

Details

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

Computational Resources
System Name	CPU Resources Used (Core x Hours)	Fraction of Usage*2(%)
TOKI-SORA	76122.24	0.00
TOKI-ST	849621.19	0.88
TOKI-GP	0.00	0.00
TOKI-XM	0.00	0.00
TOKI-LM	3510.07	0.26
TOKI-TST	110.36	0.00
TOKI-TGP	0.00	0.00
TOKI-TLM	0.00	0.00

File System Resources
File System Name	Storage Assigned (GiB)	Fraction of Usage*2(%)
/home	1024.00	1.64
/data and /data2	102400.00	0.67
/ssd	30720.00	1.87

Archiver Resources
Archiver Name	Storage Used (TiB)	Fraction of Usage*2(%)
J-SPACE	0.00	0.00

*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

ISV Software Licenses Resources
	ISV Software Licenses Used (Hours)	Fraction of Usage*2(%)
ISV Software Licenses (Total)	9623.09	6.74

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