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
Long. 25° 0′ E.
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.
