MISSION OVERVIEW
The objective of Solar A or Yohkoh (Japanese for sunbeam) is to study the high-energy radiations from solar flares (hard and soft X-rays and energetic neutrons) as well as quiet structures and pre-flare conditions. The mission is a successor to Hinotori, a previous Japanese spacecraft flown at the previous solar activity maximum in 1981.
LAUNCH DETAILS
VEHICLE
Mu-3S-II
MISSION
Yohkoh
MISSION TYPE
Earth Science
TARGET ORBIT
Low Earth Orbit
LAUNCH PAD
Mu CenterLAUNCH SITE
Uchinoura Space Center, JapanCOUNTRY
JPN
LAUNCH TIME VERIFICATION
CONFIRMEDPrecision: Minute
LAUNCH LIBRARY 2 PRIMARY
API ID: 935fd909-7f6c-4969-82ba-8cd3a01e8b9a
Reported date: Aug 30, 1991 at 02:30 UTC
Last synced: 3 hours ago
This launch date and time are confirmed by the launch provider. Countdown is active.
LAUNCH MAP
PAD WEATHER
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VEHICLE
MANUFACTURER
Institute of Space and Astronautical Science
VARIANT
S-II
FLIGHTS
8
SUCCESSES
7
SUCCESS RATE
87.5%
The Mu, also known as M, was a series of Japanese solid-fuelled carrier rockets, which were launched from Uchinoura between 1966 and 2006. Originally developed by Japan's Institute of Space and Astronautical Science, Mu rockets were later operated by Japan Aerospace Exploration Agency following ISAS becoming part of it.
FREQUENTLY ASKED QUESTIONS
When is the Mu-3S-II | Yohkoh launch?
The Mu-3S-II | Yohkoh is scheduled for Friday, August 30, 1991 at 2:30 AM UTC. This is the NET (No Earlier Than) time and may be subject to change. Current status: SUCCESS.
What rocket is being used for Yohkoh?
The Mu-3S-II | Yohkoh mission uses the Mu-3S-II rocket, manufactured by Institute of Space and Astronautical Science. The Mu-3S-II has flown 8 times with a 87.5% success rate.
Where is the Mu-3S-II | Yohkoh launching from?
The launch takes place from Mu Center at Uchinoura Space Center, Japan.
What orbit is Yohkoh going to?
The Yohkoh mission is targeting Low Earth Orbit.
Who is launching Yohkoh?
The Mu-3S-II | Yohkoh is operated by Institute of Space and Astronautical Science.
Can I watch the Mu-3S-II | Yohkoh launch live?
Yes. Visit the launch detail page on Space Launch Live for embedded YouTube webcasts, replay videos, and links to live coverage from SpaceX, NASA, NASASpaceflight, and other channels.
LAUNCH TIMELINE
Mar 29, 2026 03:06 UTC
Launch added to tracker
Imported from Launch Library 2 API
Mar 29, 2026 03:06 UTC
Launch date set: Aug 30, 1991 at 02:30 UTC
NET (No Earlier Than) confirmed by Institute of Space and Astronautical Science
Mar 29, 2026 03:06 UTC
Launch completed successfully
Updated via Launch Library 2
LIVE DATA SOURCES
Last data sync: 3 hours ago
●Launch Library 23 hours ago
Launch ID: 935fd909-7f6c-4969-82ba-8cd3a01e8b9a
●Open-Meteo Weather4 hours ago
Pad weather at 31.25, 131.08
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