The small scientific satellite INDEX was launched from the Baikonur Space Center, a Russian operated center located in the Republic of Kazakhstan, at 3:10 a.m. on August 24, 2005 (Japan standard time). After the successful launch, the satellite was re-named REIMEI. The Baikonur Space Center is an artificial town built in the vast, clay desert about 200km east from the Aral Sea. The Center is a military base famous for the launches of the world’s first man-made satellite Spunik 1 and the mission with the first human astronaut Yuri Gagarin. Today, the center frequently conducts commercial launches of U.S. and European satellites.
The launcher to carry REIMEI into space was a Dnepr Rocket, which was converted from an SS-18 ICBM (Intercontinental Ballistic Missile), developed by the former Soviet Union, to a rocket for peaceful use in commercial launches. The SS-18 was mentioned frequently in newspapers during the Cold War. Two satellites lifted off from the dedicated underground silo as scheduled. After almost perfect launch, attitude control and separation, they were put into their planned orbits.
The Dnepr Rocket carried two satellites: OICETS, the main satellite that was renamed KIRARI after the launch, and REIMEI as a piggyback satellite. It is a hot topic lately for university laboratories to develop a variety of small/micro satellites to be launched as piggybacks. ISAS is discussing the utility of small satellites too. For example, there is an opinion that we should utilize small satellites to conduct academically significant, more-advanced space exploration, observation and engineering experiment missions more frequently, more rapidly and at a lower cost. As participants in the REIMEI mission, we strongly feel that small-satellite missions are useful and promising in the future.
The REIMEI science team aimed at a small scientific exploration mission that can attain significant scientific achievements, even with a small, lightweight satellite with a few onboard observation instruments. We proposed a scientific observation plan in 1999 and engaged in R&D of onboard observation instruments. We feel that our efforts over the past six years, longer than initially planned due to various changes due to the external situation, were well rewarded with the successful launch and smooth operation of the satellite and onboard instruments. The in-orbit life of REIMEI was initially estimated one month. Even now, four months after the launch, however, all the satellite equipment (including solar-cell panel, batteries, attitude control/monitoring systems and scientific observation instruments) is sound and operating normally. Judging from the current operation status, we are convinced that prolonged continuous observation over one year or more will be possible. It is the first experience for ISAS to launch and operate such a small satellite. We will actively carry out continuous satellite observation and data analysis, and report the results to the public.
Scientific observations with REIMEI
As a REIMEI’s scientific objective, we proposed an observation plan to elucidate the fine structure of the auroral phenomena in the earth’s polar regions. Previously, observations of auroral emissions and outer-space plasmas associated with auroras have been conducted from the ground and from satellites. Previous observations, however, were unable to elucidate the fine structure, active variations and dynamics of aurora. Herein lies the significance of the REIMEI auroral observation mission.
REIMEI and scientific observation instruments before launch (with solar-cell paddle stowed). The aurora camera’s external view has a unique feature: three lenses and interference filters for three observation wavelengths. Two auroral particle sensors for electrons and ions are seen between the stowed solar-cell paddle and the satellite body. A total of five electrodes of the plasma-current monitors are also noticed.