OHSUMI, Japan's First Satellite, Reenters Earth Atmosphere After 33 Years
At 5:45 a.m. (Japan Standard Time)
on August 2, 2003, the OHSUMI, Japan's first artificial satellite,
reentered Earth’s atmosphere and vanished. The ground position
on reentry was in North Africa, in the desert area around the
border between Egypt and Libya, at Lat. 30°3’N and
It was at 1:25 p.m. on February 11, 1970 that the OHSUMI (24 kg), Japan's first satellite, was launched into orbit around Earth by No. 5 of L-4S launcher from Kagoshima Space Center (KSC) in Uchinoura. It was a great achievement of Japanese rocket technology, which had been built up since the Pencil rocket in 1955, to finally carry a domestically produced satellite into the sky on Earth. With this launch, Japan became the fourth country to launch its own satellite, following the USSR (currently Russia), the U.S., and France.
The launch was originally intended to practice the rocket inserting the satellite into orbit, so the OHSUMI had few onboard instruments, which were an accelerometer, thermometer, transmitter, and the power source of the silver oxide/zinc carbon cell. The excitement when I heard the word “catch the signal!” from the tracking station in Guam is my unfadable memory. It was the first radio wave from the OHSUMI after its launch and disappearance from view over Uchinoura.
The communication period between the OHSUMI and the ground was only for 14 to 15 hours. But, since the inserted orbit was a hyperellipse with a 337 km perigee and a 5,151 km apogee, the OHSUMI could live a long time. After reentering Earth atmosphere, the OHSUMI vanished naturally without leaving any trace, and buried itself.
The birth of the OHSUMI was the joyful culmination of my youth and also is a treasured memory for many people concerned. Hoping that Japanese space development will revive the vigorous power of solidarity of those times, we would like to celebrate the birth of the Japan Aerospace Exploration Agency (JAXA) on October 1, 2003. (Yasunori Matogawa)
October 1, 2003