New Year's Greeting JAXA sends the new year's greetings to all.

On December 24, last year, the revised roadmap for the Basic Plan on Space Policy formulated by the Japanese government was published. In response, we have renewed a sense of responsibility as the core performance agency to support the Japanese Government’s overall aerospace development and utilization while confirming the progress status of projects and missions. Specifically, we will make sure to steadily carry out each of the missions scheduled for this year, including the launch of MICHIBIKI No. 6 aboard the 5th H3 launch vehicle and the long-duration mission of astronaut ONISHI Takuya on the International Space Station (ISS). Also, we will proceed with a range of ongoing programs and measures to enhance fundamental technologies to support various missions, improve necessary facilities and equipment, and further reinforce information security measures as common infrastructure, while promoting cooperation with the government and related agencies, institutions, and business corporations to adequately serve as a connection for the industry-government-academia collaborations. For the above purposes, JAXA will put in all-out efforts across the organization.

The first topic is from the aviation field.

JAXA is engaged in the development of the “riblet” process to be applied on aircraft to reduce skin friction resistance aiming to improve fuel efficiency and diminish CO2 emissions, and cooperating with Japan Airlines Co., Ltd. (“JAL”) and O-Well Corporation (”O-Well”) to develop the relevant technology and conduct flight testing. The riblet process features fine groove structure that is inspired by the shape of shark skin, and is specifically designed to be formed on aircraft fuselage in order to control air flow on the surface for reducing skin friction resistance.
Recently, we have applied riblet coating on the fuselage of a Boeing 787-9 aircraft serving JAL’s international operations to cover approximately 30% of its surface area, representing the first of its kind in the world, for the purpose of conducting a test on long-haul flight. The related press release was posted on January 10. The planned flight, scheduled for the coming days, also marks the world’s first application of riblet coating on aircraft for international flight, which is scheduled to commence soon.

Accounting for about 40% of the total aircraft drag, skin friction constitutes the largest resistance component of the aircraft system. This means that reduction in skin friction provides the most efficient way of drag reduction.
With the riblet process under development, evaluation results have indicated that around 0.1 mm-wide fine groove formed on the fuselage surface can reduce skin friction resistance by approximately 5%. Additionally, this process is relatively easy to implement, as it can be retrofitted effectively on existing aircraft fuselage without requiring a major modification. Given this advantage, this technology is highly promising in terms of practical application.

JAXA estimated the drag reduction effect on aircraft for international flights using a model equivalent to a Boeing 787-9 and taking advantage of the strength of its Aviation Technology Directorate. In the aircraft with a 30% surface coverage of riblet process, the drag reduction rate during cruising is estimated at approximately 0.24%. According to estimates made by JAL based on the above figure, this is expected to result in an annual reduction of around 119 tons of fuel consumption and around 381 tons of CO2 emissions. This is equivalent to the annual CO2 absorption by approximately 27,000 cedar trees.
For the test aircraft, riblet coating has been applied directly on the paint surface using the Paint-to-Paint method. This coating method has been jointly patented by JAXA and O-Well. The adopted application process is a result of improvement efforts made by JAL and O-Well based on the patented technology. The direct riblet coating method is expected to reduce weight and improve durability compared to the world’s mainstream riblet processing technique using films. We have moved forward with development by stages. Specifically, since July 2022, we have been testing the durability of riblet coating applied to aircraft operated by JAL on domestic routes, and since November 2023, the application area has been expanded to cover the fuselage bottom. The planned flight test represents a significant leap taken to conduct a flight test using larger aircraft for international flight.

Moving forward, we are planning to validate the durability, aesthetics, and fuel efficiency improvement effects of the large-scale riblet coating on long-haul international flights while aiming to expand the area of application and enhance performance. JAXA will continue with the collaboration with airline and partner companies to promote research and development for the decarbonization of aircraft in pursuit of social implementation of results.

Next, I will discuss a topic related to Earth observation.

It’s an update on the ongoing mission aboard the Earth Cloud Aerosol and Radiation Explorer (EarthCARE) “Hakuryu,” which was launched into space in May last year. The spacecraft was developed and is operated jointly by Japan and Europe (the European Space Agency (ESA)). We have successfully completed commissioning and initial calibration and validation for the cloud profiling radar (CPR) onboard the satellite, and the operations have moved to the mission operation phase. The ESA has also successfully completed initial calibration and validation for the atmospheric lidar (ATLID), multi-spectral imager (MSI), and broad-band radiometer (BBR).

Accordingly, on January 14, several days ago, we started releasing Level 1 Product, which contains engineering values converted from observation data of all sensors onboard the EarthCARE satellite “Hakuryu.”
EarthCARE Products are broadly divided into Level 1 and Level 2. Level 1 Product consists of physical values or engineering values converted from observation data from sensors, and includes data on the vertical distribution and up and down motions of clouds. Level 2 Product is gained by converting engineering values from sensors into geophysical values, including data for cloud water content, cloud ice content, and optical thickness of a cloud.
Release of Level 2 Product is scheduled to be started from the middle of March 2025.
In addition, data from multiple sensors on the EarthCARE satellite “Hakuryu” will be combined to provide accurate observation data that cannot be obtained from a single sensor alone. Such data will be used to improve predictions of future climate change, contributing to studies on adaptation to climate change.

EarthCARE Products will be made publicly available for free so that the data will be used for many different purposes, including for commercial use, in addition to research and analysis. The Products are being enhanced by adding new data category such as for the velocity of global-scale up and down motions of clouds. We welcome suggestions from many people for the way of using data, looking to offer new data utilization settings.
I’d like to take this opportunity to express my deepest gratitude to many parties concerned, especially the ESA, which extended support and cooperation to us for commissioning and initial calibration and validation, and the National Institute of Information and Communications Technology (NICT), co-developer of the CPR.