Japan Successfully Launched 5th H3 Rocket Sunday; Rocket Carried Satellite to Further Improve Positioning System

The Yomiuri Shimbun

14:50 JST, February 3, 2025

Japan’s fifth H3 large-scale rocket was successfully launched from the Tanegashima Space Center in Kagoshima Prefecture at 5:30 p.m. on Sunday. The rocket, carrying the No. 6 satellite for the Michibiki Quasi-Zenith Satellite System, successfully separated from its payload 29 minutes after liftoff.

This is the fourth successful launch of the H3 rocket in a row and adds a fifth satellite to the Michibiki system, marking a significant step forward toward Japan’s goal of operating a seven-satellite constellation to independently obtain accurate location information.

Michibiki, which is managed by the Cabinet Office, is Japan’s version of the U.S.’s GPS. The system provides information that has been used in a wide range of fields, including smartphones and car navigation systems. However, due to Michibiki only currently having four satellites in its constellation, accurate location information cannot be acquired unless data is combined with systems from other countries such as GPS.

The Michibiki No. 6 is fitted with additional functions, including the ability to measure distances between satellites to improve its accuracy. All Michibiki satellites will be fitted with similar functions to minimize discrepancies to about 1 meter in the future. The latest satellite is also equipped with a U.S. sensor to monitor space debris.

The Cabinet Office plans to launch two more satellites by the end of fiscal 2025 and aims to operate a seven-satellite constellation capable of providing highly accurate location information by the end of fiscal 2026. In the future, the goal is to operate a total of 11 satellites in case there are malfunctions.

As well as providing location services for phones and cars, Michibiki’s data has been utilized for “smart agriculture” to help improve the efficiency of machinery used for harvesting as well as technology to assist driving. The system is currently being used in testing to improve the accuracy of drones that deliver packages to remote islands.

The Cabinet Office also cooperates with Japanese companies to provide positioning data to Southeast Asia and elsewhere as it aims to expand the country’s space business.

“Being able to locate a position without relying on other countries is extremely important from the perspective of national security,” Atsushi Watanabe, vice minister for policy coordination of the Cabinet Office, told reporters after the launch.