Japan: The Ally Most Likely to Add Sensors
Could Japan become the first ally to add sensors to missile defence from space?
Chapter summary
Defence space spending rose from ~¥79B (FY2022) to a reported ~¥540B (FY2025); GPI co-development; US sensors on QZSS.
Key takeaways
- 1
Japan pays about a third of the Glide Phase Interceptor and builds half of it.
- 2
Hosted payloads on QZSS are the cheapest route for allies to add sensors.
- 3
The Air Self-Defense Force becomes an air and space force from April 2027.
Key figures in this chapter
- ~¥540B
- defence space spending, FY2025 (reported)
- ¥283.2B
- counterstrike targeting constellation
- >$1B
- Japan's share of the Glide Phase Interceptor
- 880
- space operations personnel planned by end FY2026
Source: Ministry of Defense; Breaking Defense; Naval News
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