Japan’s H3 Rocket Launch Boosts Defense Satellite Program
The Japan Aerospace Exploration Agency (JAXA) successfully launched the X-band Defense Communication Satellite-3 aboard the fourth H3 Launch Vehicle (H3 F4) on November 4, 2024, at 15:48 JST from the Tanegashima Space Center. The mission marked the H-3’s first launch of a geostationary satellite.
The rocket performed as expected, with JAXA confirming the satellite's separation approximately 29 minutes and 11 seconds after liftoff. The H-3 carries the Kirameki-3 defense communications satellite.
Mission Overview: H-3 Launch Vehicle, Kirameki-3 Layload and Total Cost of $460 M USD
- Launch Vehicle: The H-3 rocket, a two-stage, cost-effective launch vehicle developed by the Japan Aerospace Exploration Agency (JAXA) and Mitsubishi Heavy Industries Ltd., took off at 3:48 p.m. JST (1:48 a.m. EST). The H-3’s recent success follows setbacks during its inaugural launch in March 2023, demonstrating progress in JAXA's capabilities for reliable satellite deployment.
- Satellite Payload: Kirameki-3, equipped with X-band communication technology, is designed to improve Japan’s Self-Defense Forces (SDF) command and control capabilities. X-band systems are noted for their resistance to interference and environmental disruptions, supporting stable and secure communications critical to military operations.
- Mission Costs: Development and operational costs for the Kirameki-3 satellite total approximately 70 billion yen (about $460 million USD).
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Japan’s H-2A vs. H-3 Rockets: Key Differences
Japan’s H-2A and H-3 rockets, developed by JAXA and Mitsubishi Heavy Industries, target different mission needs. The H-3, intended as an H-2A replacement, offers improved flexibility, cost-efficiency, and reliability.
| Feature | H-2A | H-3 |
|---|---|---|
| First Stage Engine | LE-7A; complex design, higher maintenance | LE-9; simplified design, lower cost |
| Second Stage Engine | LE-5B, reliable, re-ignitable | Improved LE-5B |
| Payload to GTO | ~6,000 kg | 4,000–7,900 kg |
| Launch Cost | ~$100 million | $50–$65 million |
| Design Complexity | Higher, more components | Reduced component count, streamlined |
| Target Launch Frequency | 3–4 launches/year | ~8 launches/year |
The H-3, developed as the H-2A's successor, offers greater payload flexibility, simplified engineering, and cost efficiencies (50% lower per kilogram launched).
Kirameki-3 provides constant, secure SDF communications from geostationary orbit.
Kirameki-3 will enter a geostationary orbit around 36,000 kilometers above the equator. This orbit enables the satellite to match Earth’s rotational period, allowing it to remain stationary relative to a fixed point on Earth’s surface. Such positioning is essential for uninterrupted communication over a designated area, supporting the SDF’s requirements for continuous operational connectivity.
H-3 placed Kirameki-3 in transfer orbit; onboard propulsion will finalize position.
Due to the challenges of achieving direct geostationary orbit, the H-3 rocket delivered Kirameki-3 into a geostationary transfer orbit, an elliptical trajectory connecting lower Earth orbit and geostationary altitude. From this orbit, the satellite will use its onboard propulsion to reach its designated position.
Kirameki-3 boosts Japan's secure satellite communications
The Kirameki-3 launch reflects Japan’s expanding military communication infrastructure as part of an ongoing response to regional security concerns. With the Kirameki series, Japan aims to enhance secure satellite communications, providing capabilities that support SDF operations across different branches and regions.
Background: Tanegashima Space Center and Yoshinobu Launch Complex
Tanegashima Space Center, Japan’s largest launch facility, has played a central role in the country’s space program since its establishment in 1969 by the Japan Aerospace Exploration Agency (JAXA). The site hosts extensive facilities, including the Yoshinobu Launch Complex, the Vehicle Assembly Building, the Spacecraft Test and Assembly Building, and the Takesaki Range Control Center, each essential for mission preparation and execution.
Within the Yoshinobu Launch Complex, Tanegashima operates two primary launch pads, known as LA-Y1 and LA-Y2. The LA-Y2 pad, located 190 meters from its counterpart, is dedicated to H-IIB rocket launches, including HTV resupply missions to the International Space Station. LA-Y2 has been active since its inaugural launch in 2009, supporting Japan’s space logistics operations.
Sources: Japan Aerospace Exploration Agency (JAXA), Mitsubishi Heavy Industries
