Japanese Planetary Missions
SAKIGAKE (MS-T5) was launched from the Kagoshima Space Center by ISAS on
January 8, 1985, and approached Halley's Comet within about 7 million km
on March 11, 1986. The spacecraft is carrying three instruments to
measure interplanetary magnetic field/plasma waves/solar wind, all of
which work normally now, so ISAS made an Earth swingby by Sakigake on
January 8, 1992 into an orbit similar to the Earth's. The closest
approach was at 23h08m47s (JST=UTC+9h) on January 8, 1992. The
geocentric distance was 88,997 km. This is the first planet-swingby for
a Japanese spacecraft.
During the approach, Sakigake observed the geotail. Some geotail
passages will be scheduled in some years hence. The second Earth-swingby
will be on June 14, 1993 (at 40 Re (Earth's radius)), and the third
October 28, 1994 (at 86 Re).
HITEN, a small lunar probe, was launched into Earth orbit on January 24,
1990. The spacecraft was then known as MUSES-A, but was renamed to Hiten
once in orbit. The 430 lb probe looped out from Earth and made its first
lunary flyby on March 19, where it dropped off its 26 lb midget
satellite, HAGOROMO. Japan at this point became the third nation to
orbit a satellite around the Moon, joining the Unites States and USSR.
The smaller spacecraft, Hagoromo, remained in orbit around the Moon. An
apparently broken transistor radio caused the Japanese space scientists
to lose track of it. Hagoromo's rocket motor fired on schedule on March
19, but the spacecraft's tracking transmitter failed immediately. The
rocket firing of Hagoromo was optically confirmed using the Schmidt
camera (105-cm, F3.1) at the Kiso Observatory in Japan.
Hiten made multiple lunar flybys at approximately monthly intervals and
performed aerobraking experiments using the Earth's atmosphere. Hiten
made a close approach to the moon at 22:33 JST (UTC+9h) on February 15,
1992 at the height of 423 km from the moon's surface (35.3N, 9.7E) and
fired its propulsion system for about ten minutes to put the craft into
lunar orbit. The following is the orbital calculation results after the
Apoapsis Altitude: about 49,400 km
Periapsis Altitude: about 9,600 km
Inclination: 34.7 deg (to ecliptic plane)
Period: 4.7 days
Copyright © 2004 Artemis Society International, for the
contributors. All rights reserved.
This web site contains many trade names and copyrighted articles and images.
ASI Web Team
Submit update to this page.
Maintained with WebSite Director.
Updated Sun, Aug 8, 1999.