Lunar/Planetary Science

In January 1985, ISAS (the present Space Science Research Division, JAXA) launched Japan’s first earth-escape mission SAKIGAKE, entering a new era by expanding its efforts to interplanetary space. In August of the same year, ISAS successfully launched SUISEI, a probe to observe the return of Halley’s Comet after 76 years. In March 1986, SUISEI, together with other satellites from Europe, USA and the former USSR, accomplished the proximity observation of Halley’s Comet and played an important role in international cooperation.

NOZOMI, the first Japanese Mars explorer launched in July 1998, had to make drastic trajectory adjustments due to problems on its journey before it managed to make an approach to Mars in December 2003, four years behind its original schedule. Injection of NOZOMI into the orbit around Mars, however, was given up because the necessary systems had been disabled by the frequent problems.

HAYABUSA (MUSES-C), an engineering experiment explorer, was launched in May 2003. After the earth swing-by in May 2005, HAYABUSA arrived at the asteroid Itokawa in September 2005. On November 26, 2005 the explorer succeeded in touchdown on the asteroid to collect samples. Its return to earth was delayed for three years due to some subsequent problems, but HAYABUSA is now operational and due back on earth in June, 2010. The scientific achievements of the Itokawa exploration have been highly praised.

In September 2007 a lunar orbiting explorer KAGUYA (SELENE) was launched and is now carrying out its observation mission using a variety of onboard instruments. The rising and setting of a radiant blue earth captured by NHK’s high-definition camera aboard the explorer moved many viewers. Other projects now under way are the Venus exploration project, PLANET-C, and the Mercury exploration project, BepiColombo.