Background to the Research and Development
JAXA, in collaboration with the National Astronomical Observatory of Japan (NAOJ) and Mitsubishi Electric Corporation, has been selected for the JST K Program (Grant Number JPMGKP24N1). At JAXA, this initiative will be implemented as the OSCAR-J Project.
Through this R&D program, the partners aim to develop the core technologies for a large-scale, high-precision optical antenna (optical telescope) capable of providing Earth observation performance even from geostationary orbit. To achieve this goal, JAXA is focusing on segmented-mirror technology, in which multiple mirror segments function together as a single large primary mirror. Applying segmented-mirror technology to an optical Earth observation satellite operating at visible wavelengths would represent a world first.
Building on Japan’s strengths in advanced materials, precision manufacturing, and optical sensor technologies, the project will conduct ground-based demonstrations to support the development of a large space-based optical telescope with an aperture class of approximately 3.6 meters. Specifically, a full-scale breadboard model will be designed and manufactured, and optical testing will be conducted at ground-based facilities to verify the feasibility of the segmented-mirror technology.
Future Space Applications Targeted by This R&D
To meet emerging Earth observation needs, including observation at any time (persistent coverage), rapid observation of areas of interest (timely access), and continuous monitoring of the same location (continuous observation), this project aims to realize a new wide-area observation system. This concept combines the unique advantage of geostationary orbit, which enables continuous coverage of the same region, with large-aperture optical-antenna technology capable of delivering extremely high spatial resolution.
This R&D effort aims to enable a wide range of unprecedented space-based applications. These include public-sector applications such as disaster prevention, disaster response, and national resilience, as well as private-sector applications such as infrastructure monitoring and economic-activity assessment. In addition, the optical-antenna technologies developed through this project are expected to support further applications, including high-speed optical communications between Earth and the Moon and astronomical observations using space telescopes.
Roles and Responsibilities in the R&D
Based on the K Program selection results, JAXA, NAOJ, and Mitsubishi Electric Corporation will share the responsibilities outlined below and work together to advance this R&D effort.
- JAXA: In collaboration with NAOJ and Mitsubishi Electric, JAXA will conduct R&D on segmented-mirror technology, including optical testing (synthetic-aperture testing) using a breadboard model of an optical antenna with an aperture class of approximately 3.6 meters.
- Mitsubishi Electric Corporation: Will conduct R&D on foundational technologies for spacecraft digital twins to improve development efficiency by enabling more accurate predictions of optical performance in the on-orbit environment than are possible using conventional methods.
- National Astronomical Observatory of Japan (NAOJ): Will conduct R&D on optical-surface metrology technologies for large convex mirrors, enabling precise measurements under test conditions that have traditionally presented significant technical challenges.
JAXA’s Planned R&D Activities
JAXA plans to undertake the following activities as part of this program:
- R&D on core technologies required for segmented mirrors
Realizing a segmented-mirror system requires several key capabilities, including the ability to manufacture multiple mirror segments with high precision and stability, accurately align the segments, and use advanced metrology techniques to verify and maintain their alignment. JAXA will conduct R&D on these essential technologies. - Demonstration of the feasibility of segmented-mirror technology for space applications
To demonstrate the feasibility of a segmented-mirror system with an aperture class of approximately 3.6 meters, JAXA will design and fabricate a full-scale breadboard model and evaluate its performance through optical testing (synthetic-aperture testing). These activities will verify the suitability and performance of segmented-mirror technology for future space-based optical systems.
Research Area 1: Development of Core Technologies for Segmented Mirrors
- Fabrication of multiple 1.3-meter-class mirror segments for use in a segmented-mirror system
- R&D on precision alignment mechanisms for mirror segments
- R&D on high-precision metrology technologies for evaluating the performance of segmented-mirror assemblies
Research Area 2: Fabrication and Evaluation of a Large Segmented Mirror for Space Applications
- Fabrication of a breadboard model of an optical antenna with an aperture class of approximately 3.6 meters
- Optical testing of the segmented mirror using the breadboard model (synthetic-aperture testing)