Epsilon S
In DevelopmentIHI Aerospace / JAXA · Japan · First flight FY20
Japan's upgraded solid-fuel small satellite launcher, developed from the Epsilon series, with a first stage sharing the SRB-3 booster design of H3. Its new second-stage motor exploded in static fire tests in July 2023 and November 2024, so JAXA decided in 2026 to fly a Block 1 version with the conventional Epsilon second stage, targeted for fiscal 2026 with lower capability than the original design.
Launch price
Not published
Career record
No counted launches yet
as of 2026-10-09
Next launch
NET 2026
JV-LOTUSat-1
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More launch calendarsLaunch activity, live
From SpaceNexus's launch tracker (tracked since Dec 31, 2026); outcomes recorded as each flight lands. Career totals above are the vehicle's full history.
Last 90 days
0
launches flown
Tracked flights
0
0 success · 0 partial · 0 failed
Tracked success rate
–
full successes / attempts; partial failures are not successes
On the manifest
2
upcoming launches
Upcoming
Specifications
| Height | 26.8 m |
| Stages | 3 |
| Engines | SRB-3 (1st) + conventional Epsilon second-stage motor (Block 1) + enlarged third-stage motor with thrust vector control |
| Propellant | Solid (HTPB composite) |
| Reusable | No |
| First flight | FY2026 target (Block 1, not yet flown) |
| Last flight | – |
| Variants seen on the manifest | Epsilon S |
Frequently asked
How much does a Epsilon S launch cost?
IHI Aerospace / JAXA has not published a list price for Epsilon S.
When is the next Epsilon S launch?
The next tracked Epsilon S launch is JV-LOTUSat-1, NET 2026 from Uchinoura Space Center, Japan. Dates move; Mission Control carries the live countdown.
How reliable is Epsilon S?
Epsilon S has no counted launches yet as of 2026-10-09, so it has no career success rate. The tracked flights below come from SpaceNexus's launch tracker.
How much can Epsilon S carry?
IHI Aerospace / JAXA has not published payload figures for Epsilon S that we could verify.