11:00 〜 13:00
[PPS06-P05] Status on Japanese Lunar Polar Exploration (LUPEX) Mission
キーワード：月探査、月水氷、資源可用性、揮発性物質
Japanese lunar exploration missions:
The presence, quantity, quality, and usability of water ice should be measured directly on the Moon to assess whether it can be used as a resource. Furthermore, in order to estimate the quantity and quality of water throughout the Moon, it is also necessary to obtain data to understand the principles of water distribution and concentration.
In recent years, the lunar polar regions have been attracting attention from the viewpoint of securing water and energy resources, and international competition and cooperation for water resource availability research missions, including private ones, are intensifying with the aim of landing in the early 2020s. Therefore, it is becoming more and more important to have a mission to confirm the existence and availability of water resources in the lunar polar region without delaying behind other countries, and to contribute to the establishment of surface exploration technology for gravitational bodies and to secure valuable resource exploration areas. The Lunar Polar Exploration (LUPEX) is a mission conducted in cooperation with international partners India, the United States, and Europe. In particular, LUPEX will not only strengthen the good relationship with India, which is an important diplomatic country for Japan, but also contribute to diplomacy and security.
Spacecraft configuration:
The spacecraft system consists of a lander and a rover, with ISRO in charge of the lander, JAXA in charge of the rover development and procurement of launch services, and JAXA, ISRO, NASA, and ESA in charge of the instruments. The target mass of the spacecraft system (including the lander and the rover system of about 350 kg) is about 6 tons. After transfer to lunar orbit, the spacecraft will be injected into a circular orbit at an altitude of 100 km after several orbit maneuvers. During the powered descent, the position of the spacecraft system will be estimated by landmark navigation using the shadows created by the terrain. After landing, the rover will be deployed from the lander to the lunar surface, and then the rover will start observing water resources using its onboard instruments.
Status on the mission:
ISRO/JAXA has almost completed the Phase-A activities (conceptual design) based on the Implementation Arrangement (IA) of the LUPEX mission. In January 2022, the project passed the domestic System Definition Review (SDR), which is one of the JAXA technical gate reviews, and in February of the same year, the project passed the Project Transition Review, which is a JAXA management review, and the Phase-B activities (basic design) are scheduled to start thereafter.
International competitiveness of rovers and instruments:
One of the major goals of LUPEX is to map the horizontal and vertical distribution of water by directly measuring the horizontal and vertical distribution of water content (0.1 wt% accuracy). Since the water content of 0.5wt% is the break-even point in the initial study of fuel production at the Moon site (In-Situ Resource Utilization: ISRU), the measurement with 0.1wt% accuracy is targeted. The key technologies required to realize these specifications are as follows:
- Direct measurement of water content: An integrated measurement device that performs a series of measurements from direct measurement of moisture content to identification of molecular weight and molecular species in volatile gases.
- High-precision vertical acquisition of sample: Local sample collection mechanism (error of less than 3cm) using auger-tip clamshell.
- Horizontal exploration in various environments: Four-legged crawler traveling system that can climb and descend on high slopes.
- Survivability: thin-film solar cells and Li-ion battery cells with ultra-high energy density and wide operating temperature range.
In this paper, these key technologies and their advantages over other spacecrafts are described.
The presence, quantity, quality, and usability of water ice should be measured directly on the Moon to assess whether it can be used as a resource. Furthermore, in order to estimate the quantity and quality of water throughout the Moon, it is also necessary to obtain data to understand the principles of water distribution and concentration.
In recent years, the lunar polar regions have been attracting attention from the viewpoint of securing water and energy resources, and international competition and cooperation for water resource availability research missions, including private ones, are intensifying with the aim of landing in the early 2020s. Therefore, it is becoming more and more important to have a mission to confirm the existence and availability of water resources in the lunar polar region without delaying behind other countries, and to contribute to the establishment of surface exploration technology for gravitational bodies and to secure valuable resource exploration areas. The Lunar Polar Exploration (LUPEX) is a mission conducted in cooperation with international partners India, the United States, and Europe. In particular, LUPEX will not only strengthen the good relationship with India, which is an important diplomatic country for Japan, but also contribute to diplomacy and security.
Spacecraft configuration:
The spacecraft system consists of a lander and a rover, with ISRO in charge of the lander, JAXA in charge of the rover development and procurement of launch services, and JAXA, ISRO, NASA, and ESA in charge of the instruments. The target mass of the spacecraft system (including the lander and the rover system of about 350 kg) is about 6 tons. After transfer to lunar orbit, the spacecraft will be injected into a circular orbit at an altitude of 100 km after several orbit maneuvers. During the powered descent, the position of the spacecraft system will be estimated by landmark navigation using the shadows created by the terrain. After landing, the rover will be deployed from the lander to the lunar surface, and then the rover will start observing water resources using its onboard instruments.
Status on the mission:
ISRO/JAXA has almost completed the Phase-A activities (conceptual design) based on the Implementation Arrangement (IA) of the LUPEX mission. In January 2022, the project passed the domestic System Definition Review (SDR), which is one of the JAXA technical gate reviews, and in February of the same year, the project passed the Project Transition Review, which is a JAXA management review, and the Phase-B activities (basic design) are scheduled to start thereafter.
International competitiveness of rovers and instruments:
One of the major goals of LUPEX is to map the horizontal and vertical distribution of water by directly measuring the horizontal and vertical distribution of water content (0.1 wt% accuracy). Since the water content of 0.5wt% is the break-even point in the initial study of fuel production at the Moon site (In-Situ Resource Utilization: ISRU), the measurement with 0.1wt% accuracy is targeted. The key technologies required to realize these specifications are as follows:
- Direct measurement of water content: An integrated measurement device that performs a series of measurements from direct measurement of moisture content to identification of molecular weight and molecular species in volatile gases.
- High-precision vertical acquisition of sample: Local sample collection mechanism (error of less than 3cm) using auger-tip clamshell.
- Horizontal exploration in various environments: Four-legged crawler traveling system that can climb and descend on high slopes.
- Survivability: thin-film solar cells and Li-ion battery cells with ultra-high energy density and wide operating temperature range.
In this paper, these key technologies and their advantages over other spacecrafts are described.