Efforts are intensifying toward the commercialization of optical communication satellite constellations, which coordinate multiple satellites to enable high-capacity communications using lasers.

Japan is also advancing technological development in this field through a public-private partnership, and the launch of demonstration satellites will begin in earnest next year or later.

Highly secure next-generation technology

A satellite constellation -- which is assembled through launching and coordinating multiple satellites -- is better at ensuring uninterrupted observation and communication than relying on a single large satellite, as, if some satellites in the constellation fail, others can compensate.

A well-known example of this principle is the Starlink constellation, built by SpaceX. By transmitting data via radio waves through a network of nearly 10,000 satellites, it can provide connectivity to users even in locations such as Antarctica, tropical rainforests and remote islands.

Optical communication satellite constellations represent the next generation of this technology. Light waves have a higher frequency than radio waves, allowing them to be used to transmit more data in the same amount of time. Radio waves used by conventional communication satellites tend to spread in concentric circles, making them vulnerable to interception; in contrast, light travels in a straight line and reaches only a narrow area, offering a high level of confidentiality.

One Indian research firm predicts that the market for the optical communication satellite business will grow by 23% annually between 2025 and 2030. The Japanese government has set a goal of using its "K-Program," which promotes public-private collaboration on developing technologies of national importance, to have a demonstration of optical communication satellite technology conducted in space by fiscal 2031.

Space Compass Corp., a joint venture between NTT Inc. and satellite communications company SKY Perfect JSAT Corp., is leading the public-private research team receiving support under this program. Other participants include satellite developer Axelspace Corp., NEC Corp. and the National Institute of Information and Communications Technology (NICT).

Space Compass aims to establish a service for using optical communications satellites to rapidly transmit data acquired by Earth observation satellites to the ground. Ryota Tanaka, director of the Space DC Business Division at Space Compass, said, "We want to speed up data transmission, which has traditionally taken anywhere from several hours to several days." If this kind of high-capacity communication is realized, it could be used for purposes such as remote vehicle control and securing communication channels during disasters.

Aiming for a global communication network

The team plans to launch six optical communication satellites into orbit at an altitude of approximately 1,000 kilometers between fiscal 2027 and 2029. They will also equip Earth observation satellites with optical communication terminals and conduct demonstration tests of their data transmission and reception functions.

NEC and Axelspace will each develop their own satellites and establish interconnection technology to enable optical communication between satellites operated by different companies. Takashi Eishima, a director at Axelspace, said, "Precise satellite attitude control technology is necessary to accurately transmit and receive laser beams between satellites that are constantly moving at high speeds."

NICT plans to conduct demonstration tests of an "integrated control system" that will use the two companies' satellites to efficiently transmit data through multiple satellites to a final destination. Hiroyuki Tsuji, director general of NICT's Wireless Network Research Center, said, "Even if individual companies cannot compete with SpaceX based on the number of satellites they own, we can realize a global communications network if we have the technology to coordinate the satellites of various companies."

Relay via geostationary satellites

As a step in creating an optical communication satellite constellation, there are also plans to deploy relay satellites in geostationary orbit at an altitude of 36,000 kilometers. When transmitting data from low-Earth orbit satellites to the ground, it is usually necessary to wait for the satellite to move directly over the receiving ground station. The addition of relay satellites will make it possible to transmit data to the ground in near real time from any orbit.

The government's Engineering Test Satellite 9 (ETS-9), scheduled for launch as early as next year, will attempt optical communication with a ground station. The optical communication equipment on board will be made with optical fiber components mass-produced in Japan. Alberto Carrasco-Casado, a senior researcher at NICT, explains that they aim to pave the way for industrializing production of this equipment by using components that can be procured in Japan.

Optical communication has the weakness of being susceptible to atmospheric conditions, such as being blocked by clouds. When skies are not clear, radio waves are the more practical option for communication with ground stations, so a satellite constellation combining optical and radio waves is expected to be more effective than one that uses only a single type.

A senior official at the Economy, Trade and Industry Ministry who is responsible for promoting the space industry, stated, "We want to support the efforts of companies aiming to industrialize (the production of optical communication satellite technology)."

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This article is from The Yomiuri Shimbun. Neither Dow Jones Newswires, MarketWatch, Barron's nor The Wall Street Journal were involved in the creation of this content.

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July 13, 2026 06:45 ET (10:45 GMT)

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