H3
OperationalJAXA / MHI · Japan · First flight 2023
Japan's flagship launch vehicle succeeding the H-IIA. Features the expander bleed cycle LE-9 engine, designed for improved reliability and reduced cost. Its December 2025 flight lost the Michibiki 5 navigation satellite after five consecutive successes; JAXA traced the failure to a damaged payload adapter. H3 returned to flight in June 2026 on the first three-engine configuration flight and flew again in August 2026.
Launch price
Not published
Payload to GTO
6,500 kg
Career record
77.8%
7/9 successful · as of 2026-10-09
Next launch
Oct 19, 2026
Martian Moons eXploration (MMX)
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More launch calendarsLaunch activity, live
From SpaceNexus's launch tracker (tracked since Feb 2, 2025); outcomes recorded as each flight lands. Career totals above are the vehicle's full history.
Last 90 days
1
launches flown
Tracked flights
5
4 success · 0 partial · 1 failed
Tracked success rate
80%
full successes / attempts; partial failures are not successes
On the manifest
8
upcoming launches
Upcoming
Specifications
| Height | 63 m |
| Diameter | 5.2 m |
| Liftoff mass | 574,000 kg |
| Stages | 2 |
| Engines | 2 or 3x LE-9 + 0/2/4x SRB-3 + 1x LE-5B-3 |
| Propellant | LH2 / LOX + HTPB (SRBs) |
| Fairing diameter | 5.2 m |
| Payload to GTO | 6,500 kg |
| Payload to SSO | 4,000 kg |
| Reusable | No |
| First flight | 2023-03-07 |
| Last flight | Active |
| Variants seen on the manifest | H3, H3-22, H3-24, H3-30 |
Where it launches from
Frequently asked
How much does a H3 launch cost?
JAXA / MHI has not published a list price for H3.
When is the next H3 launch?
The next tracked H3 launch is Martian Moons eXploration (MMX), Oct 19, 2026 from Tanegashima Space Center, Japan. Dates move; Mission Control carries the live countdown.
How reliable is H3?
H3 has flown 9 times as of 2026-10-09, with 7 successes, 2 failures and 0 partial failures: a 77.8% success rate, with 2 consecutive successes at last count.
How much can H3 carry?
6,500 kg to geostationary transfer orbit, 4,000 kg to sun-synchronous orbit.
Public commitments
On the Promise Ledger: 1 entry: 1 revised. Exact words, primary sources, deadlines and outcomes.
What the statuses mean
- Revised:
- the date or quantity was moved before it came due.
The whole Promise Ledger · same rules for everyone, how entries are scored