Japan's H3 Rocket Successfully Launches ALOS-4

Japan's H3 rocket successfully launched the Advanced Land Observing Satellite-4 (ALOS-4), also known as DAICHI-4.

The rocket lifted off from the Tanegashima Space Center at 11:06 p.m. Eastern, June 30 (0306 UTC, July 1), marking another successful mission for the Japan Aerospace Exploration Agency (JAXA). Watch: https://youtu.be/a3JbUpYIRtw

The two-stage launch vehicle performed flawlessly, and ALOS-4 separated from the rocket approximately 16 minutes and 34 seconds after liftoff. JAXA confirmed that ALOS-4’s solar arrays fully deployed, as verified by telemetry data received from the satellite at JAXA Mingenew Station in Australia.

This launch follows the H3's successful second flight in February. The H3’s inaugural launch in March 2023 faced challenges, suffering a second stage engine failure that led controllers to issue a destruct command to destroy the stage and its ALOS-3 payload. This setback caused a delay in Japan's Martian Moons eXploration (MMX) mission, which aims to collect samples from the Martian moon Phobos and return them to Earth. The MMX mission is now targeting a Martian launch window in 2026.

ALOS-4, developed by prime contractor Mitsubishi Electric Corporation, is equipped with a phased array type L-band synthetic aperture radar (PALSAR-3).

Positioned in a sun-synchronous orbit, the satellite offers enhanced observation capabilities compared to its predecessor, ALOS-2, and its PALSAR-2 payload. The radar satellite can conduct day and night observations and penetrate clouds, making it invaluable for monitoring disaster-hit areas, forests, and sea ice.

Additionally, ALOS-4 will address new monitoring areas such as infrastructure displacement.

"It will be able to provide evidence of ground transformation caused by volcanic activity or an earthquake on a scale of up to a few centimeters through comparison of data acquired during separate observations." - JAXA

The satellite features an increased swath width of 200 kilometers, compared to ALOS-2's 50 kilometers, while maintaining high resolution.

ALOS-4 is also equipped with an Automatic Identification System for ships (AIS) receiver, allowing it to monitor oceans by receiving AIS signals from vessels.

The successful flight of the H3 rocket is a significant boost for Japan’s space program. The H3 rocket, set to replace the H-2A, is designed to be the country's workhorse for both civilian and military missions, including exploration missions and International Space Station (ISS) resupply with the HTV-X cargo spacecraft. The H3 rocket comes in configurations with no solid rocket boosters, two SRBs, or four SRBs for higher payload needs. The latter two variants can also utilize an elongated payload fairing, making the rocket versatile for various mission requirements.

Moreover, the H3 is engineered to be more cost-effective, enhancing its competitiveness in the international commercial launch market. JAXA is also exploring the development of a large, reusable launch vehicle as a core component of its future space transportation plans.

The successful launch of ALOS-4 underscores Japan's growing capabilities and ambitions in space exploration and satellite technology, paving the way for more advanced missions and international collaborations.