The brief

Analyst view

• MHI is prime contractor for Japan's H3, targeting $33.9M per launch for the H3-30 variant (no solid boosters).
• Approved in May 2013, first flight March 2023; seven successful missions by August 2026 after two failures.
• H3-24 lifts 7,900 kg to geostationary transfer orbit; H3-30 lifts 4,000 kg to sun-synchronous orbit.

Technical approach

As reported

Engines

LE-9 expander-bleed engines

Uses newly designed LE-9 hydrogen engine with expander-bleed cycle, trades power for lower cost.

Modularity

Multiple configurations

H3-30 flies without solid boosters; H3-24 adds two or four SRB-3 solid boosters for heavier payloads.

Hydrogen fuel

High specific impulse

Both stages use liquid hydrogen and oxygen for high Isp, at cost of cryogenic complexity.

Manufacturing

Cost-optimized design

Single engines per stage instead of clusters; streamlined avionics to lower per-flight costs.

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