Reimei ('Dawn') is the in-flight name for a small Japanese satellite known during development as INDEX (INnovative-technology Demonstration Experiment), developed in-house at JAXA both to serve as a demonstration of small-satellite technologies (particularly high-performance and high-accuracy

attitude control Attitude control is the process of controlling the orientation of an aerospace vehicle with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle ...

) and to perform simultaneous optical and charged-particle observation of the

aurora An aurora (plural: auroras or aurorae), also commonly known as the polar lights, is a natural light display in Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic). Auroras display dynamic patterns of bri ...

. A notable feature is the 25 μm-thick polyimide mirrors used for concentrating sunlight onto the solar arrays. It is and weighs 72 kilograms. The construction budget was $4 million. The satellite was launched into a near- sun-synchronous 630 km orbit on 24 August 2005 as a

piggyback Piggyback, piggy-back, or piggybacking may mean: Transport * Piggyback (transportation), something that is riding on the back of something else Art, entertainment, and media * Splash cymbal piggybacking, mounting a cymbal on top of an already ...

on the OICETS launch on the Dnepr launch vehicle.

References

{{Japanese space program Satellites of Japan Spacecraft launched by Dnepr rockets Spacecraft launched in 2005