Japan has successfully launched the last of the current generation of the satellite navigation orbiters it will use to operate a sovereign positioning system.

The satellite, known as “Michibiki No. 7”, aka QZS-7, made it into orbit early on Tuesday, local time, aboard an H3 rocket.

The H3 is the Japan Aerospace Exploration Agency’s (JAXA’s) latest mid-range launcher and has flown nine times. Two of those missions failed, most recently in December 2025 when glue caused fatal problems. The payload of that flight was QZS-5 – an earlier satellite navigation orbiter.

Japan wants its own satellite positioning system because Global Positioning System (GPS) signals can’t always reach all locations across the country – especially mountainous regions or parts of the nation’s super-dense cities. The Japanese government therefore decided to create its own Quasi-Zenith Satellite System (QZSS) to ensure universal coverage, and greater location accuracy.

As Japan’s Cabinet Office explains here, QZSS complements GPS by ensuring that a positioning satellite is nearly always above Japan and therefore able to provide excellent local service.

Japan’s many islands span latitudes from 20° to 45° North, too far from the equator for a geostationary satellite alone to provide the desired coverage. The QZSS sats therefore use an inclined geostationary orbit that has a figure eight pattern illustrated below.

The orbit you see above means satellites move more slowly when they are above the Northern Hemisphere, meaning they spend around 13 hours at a time above the equator and many hours visible from Japan.

The first configuration of the QZSS used four satellites, one of which appeared over Japan every eight hours. One satellite was always at an elevation of 70° or more, but not necessarily at the highest point in the sky – the zenith. That fact gave the system its name.

The first experimental QZSS satellite went aloft in 2010, and four production birds were launched between 2017 and 2021.

Japan’s government later decided to expand the system to seven orbiters. QZS-6 launched in February 2025, before the launch of QZS-5 failed in December. Tuesday’s launch saw QZS-7 reach its intended orbit.

Plans call for another three satellites sometime in the 2030s, but no replacement for QZS-5. For now, Japan has almost all the satnav coverage it wants, and a little more confidence that the H3 can become a reliable space truck. ®