As part of a whole-of-government effort, the Japanese government is considering building and launching space-based Space Situational Awareness (SSA) satellites to better monitor space debris and anti-satellite threats against Japanese satellites, according to a report in Japan News.
Several government sources suggest that launch of SSA satellites capable of monitoring an area in space is being planned during fiscal years 2024-2028.
The government will revise its National Defense Program Guidelines, the basic framework for the nation’s defense policy, at the end of this year. The new guidelines are expected to mention that “the entire government will be involved in efforts to significantly strengthen space situational awareness capabilities,” according to Japan News.
SSA satellites monitor the movement of suspicious satellites, as well as space debris circling Earth at high speed — fragments of rockets, satellites that no longer operate, and other objects. If the SSA satellite recognizes a Japanese satellite is in danger, it will notify operators on the ground who can instruct the satellite to change its orbit and avoid a collision.
The government estimates each SSA satellite will cost about ¥15 billion (U.S.$135.7 million), with each rocket launch costing from ¥5 billion to ¥10 billion (U.S.$45.2 to U.S.$90.4 million), according to the sources quoted in Japan News.
The rapidly increasing presence of space debris, and the development of so-called “killer satellites,” – which can cripple a targeted satellite — by the Chinese and Russian militaries, pose growing threats to Japanese satellites. Therefore, the Japanese government has begun to consider introducing SSA satellites.
The Japanese government is also currently developing a ground-based satellite-monitoring system which uses powerful radar and optical telescopes, which is scheduled to start operating from fiscal 2023. However, some analysts contend that this type of system will struggle to maintain its monitoring capabilities during bad weather.
By contrast, an SSA satellite can monitor a satellite at close range without being affected by the weather, enabling it to accurately gauge the presence of space debris and suspicious satellites.
The U.S. military currently operates several SSA satellites, and the Japanese government plans to work closely with the U.S. as it considers introducing such satellites. According to the sources quoted in Japan News, senior officials in the Defense Ministry; the Self-Defense Forces; the Education, Culture, Sports, Science and Technology Ministry; and other agencies, plan to participate in multinational war games involving SSA satellites, scheduled to be held in the United States later this year.