TEST LAUNCH OF JAPAN’S H3 ROCKET, June 11, 2026, 8:53 pm EDT, Tanegashima, Japan (June 12, 9:53 am Japan Time)

Update, June 9:  The new launch date is June 12 at 9:53:59 am Japan Time (June 11, 8:53:59 pm EDT). The launch window that day closes at 11:52:46 am Japan Time (10:52:46 pm EDT).

Update, June 8: JAXA just posted on X that the launch is postponed due to weather. A new date is pending.  The launch window is open through June 30.

[Press Release]

Launch Postponement of H3 Launch Vehicle flight No.6, 30 configuration Test Vehiclehttps://t.co/L0R18CT6Fk

— JAXA(Japan Aerospace Exploration Agency) (@JAXA_en) June 8, 2026

Update: As of June 6, JAXA’s website and X feed don’t specifically confirm the launch date, but JAXA had a press conference on May 25 about a secondary payload that will be carried and that webpage continues to show the same launch date (June 10 at 9:53:49 am in Japan, which is June 9, 8:53:49 pm EDT).

Update: As of May 13, this is still on track for launch according to Japan’s NHK news organization, but JAXA’s website has not been updated since April 24.

Original Entry: JAXA will launch the H3 rocket on a test flight on June 10, 2026 at 9:53:59 am Japan Standard Time (which is June 9 at 8:53:59 pm Eastern Daylight Time) from Tanegeshima, Japan. The launch window is open until 11:52:46 am on June 10 JST (which is 10:52:46 am on June 9 EDT).

The “reserved launch period” is through June 30.

More information is on JAXA’s website.

The test launch follows a failure on December 22, 2025 JST that led to the loss of the QZS-5 navigation satellite on December 22, 2025 JST.  The satellite reportedly separated from the rocket during stage separation between the first and second stages and fell into the ocean. The cause was later reported to be due to adhesive strips in the payload support structure peeling off.