|Sakikage - |
Credit: NASDA. 23,412 bytes. 317 x 291 pixels.
Series of spacecraft of varying configurations built for engineering tests of scientific satellite equipment.
Engineering test for the launching of scientific satellites. Injection point 29.7 N, 145.8 E
Attitude control satellite (performance test of launch vehicle).
Tentative name before launching: MS-T3. Launching organization: Institute of Space and Aeronautical Science, University of Tokyo. Radio frequencies: 136.725 MHz, tracking; 400.500 MHz, telemetry. Active life: two weeks. Function: (1) Test of the overall p erformance of the newly developed launch vehicle, M-3H-1. (2) Experiment of magnetic stabilization. (3) Observation of ultraviolet radiation.
Sakigake ('Pioneer') was a test spacecraft similar to Suisei (Planet-A). Objectives were :verification of fundamental technology related to interplanetary missions, including deep-space communication, attitude control, attitude determination; study and observation of solar wind and plasma waves and interplanetary magnetic field. It carried three instruments to measure plasma wave spectra, solar wind ions, and interplanetary magnetic fields. The spacecraft was spin-stabilized at two different rates (5 and 0.2 rpm). It was equipped with hydrazine thrusters for attitude and velocity control, star and sun sensors for attitude determination, and a mechanically despun off-set parabolic dish for long-range communication. Launched into an initial heliocentric orbit with a period of 318.8 days, at 151.4 x 121.9 million km (0.815 x 1.012 AU), 1.439 degree inclination. Flew by Comet Halley on its sunward side at a distance of about 7 million kilometers on March 11, 1986. It later made an Earth swingby on January 8, 1992 with a closest approach of 88,997 km. This was the first planet-swingby for a Japanese spacecraft. During the approach, Sakigake observed the geotail, with passage occurring at 290 Re on 14 June 1993 before ISTP's multi-spacecraft investigation of that region. The second Earth swingby was on June 14, 1993 at 40 Re, and the third on October 28, 1994 at 86 Re. Almost no hydrazine remained so no further maneuvers were accomplished. Telemetry contact was lost on 15 November 1995 at a distance of 106 million km. Future mission planning had included a 23.6 km/s, 10,000 km flyby of Comet Honda-Mrkos-Pajdusakova on Feb 3, 1996 (approaching the nucleus along the tail) some 0.17 AU from the Sun, and a 14 million km passage of Comet Giacobini-Zinner on Nov 29, 1998.