Small Bodies Mission Support

Suisei (Planet-A) was a mission to comet 1P/Halley planned by Japan's Institute of Space and Astronautical Science (ISAS). The mission was a chance to study an interplanetary object and test a new launch vehicle. To confirm the performance of the newly developed launch system the test spacecraft Sakigake was launched on 8 January 1985. The launch of Sakigake was successful and it continued on to encounter comet 1P/Halley.

Suisei was launched from Kagoshima Space Center on 18 August 1985. The spacecraft carried two instruments in order to study the the growth and the decay of the cometary object's hydrogen corona, and the interaction of the solar wind with the cometary ionosphere. Suisei encountered 1P/Halley on 8 March 1986 at a distance of 151,000 kilometers on the sunward side.

The spacecraft's thrusters were depleted of hydrazine on 22 February 1991 causing future planned encounters to be canceled. ISAS had planned to send Suisei by 21P/Giacobini-Zinner on 24 November 1998 and 55P/Tempel-Tuttle on 28 February 1998.

The Suisei Mission Description is available from the National Space Science Data Center database.

The SBN is the PDS node leading the efforts to restore and archive the data from the small body missions such as the Suisei mission.

Instrument/Investigation	Measuring	Small Bodies Data available below
Ultraviolet Imager (UVI)	Succession of synoptic images of the cometary object's hydrogen corona at the hydrogen Lyman-alpha line	none
Energy Spectrum Particle (ESP)	Velocity distributions of the solar-wind ions and electrons in the energy range between 0.03 and 16 keV	1P/Halley

Instrument/ Investigation Description	Target	Description of Available Data	Data Link
ESP	1P/Halley	International Halley Watch data	CDROM

Target	Target Type	Other Data Sets Targeting this Object
1P/Halley	Comet	International Halley Watch CDROM archive