H3 (rocket)

The H3 is a next-generation family of rockets developed by Mitsubishi Heavy Industries (MHI) and the Japan Aerospace Exploration Agency (JAXA). It is designed as a successor to the H-IIA and H-IIB rockets, aiming to provide a more cost-effective and versatile launch vehicle for a variety of missions, including governmental and commercial satellite deployments, as well as future space exploration endeavors.

Key features of the H3 include a simplified design to reduce manufacturing and operational costs, a higher payload capacity compared to its predecessors, and improved launch reliability. The rocket is configurable with different numbers of LE-9 engines (the main engine) and solid rocket boosters (SRBs) to match specific mission requirements, allowing for optimized performance and affordability. The LE-9 engine utilizes a staged combustion cycle, a technology aimed at improving efficiency and reducing emissions.

The development of the H3 involved significant efforts to enhance international competitiveness in the space launch market. Its modular design and adaptable configurations are intended to make it appealing to a wide range of customers.

The first launch of the H3, carrying the Advanced Land Observing Satellite-3 (ALOS-3), failed in March 2023 due to an anomaly during the second stage ignition. A subsequent successful launch occurred in February 2024, deploying a demonstration payload.