Kyushu University has initiated IDEA the project for in-situ debris environmental awareness. This project aims at a prompt and clear understanding of the current and future micron-size debris environment in the low Earth orbit region. Orbital debris, even smaller than 1 mm, may cause a fatal damage on a spacecraft because of a high relative velocity at impact. Micron-size debris could be one of major threats against safe and secure space development and utilization for humankind. However, the current micron-size debris environment has not been defined well because measurements are quite limited in terms of orbital regimes and not continuously available yet. Thus, the IDEA project proposes to deploy a group of micro satellites, those conduct in-situ and near real-time measurements of micron-size debris, into any orbital regimes to be monitored. This paper briefly introduces the IDEA project and micron-size debris modeling to define and dynamically update the current environment using measurements continuously acquired through the IDEA project.