The Korea Astronomy and Space Science Institute plans to develop a coronagraph in collaboration with National Aeronautics and Space Administration (NASA) and to install it on the International Space Station (ISS). The coronagraph is an externally occulted one-stage coronagraph with a field of view from 3 to 15 solar radii. The observation wavelength is approximately 400~nm, where strong Fraunhofer absorption lines from the photosphere experience thermal broadening and Doppler shift through scattering by coronal electrons. Photometric filter observations around this band enable the estimation of 2D electron temperature and electron velocity distribution in the corona. Together with a high time cadence ($<$12~min) of corona images used to determine the geometric and kinematic parameters of coronal mass ejections, the coronagraph will yield the spatial distribution of electron density by measuring the polarized brightness. For the purpose of technical demonstration, we intend to observe the total solar eclipse in August 2017 with the filter system and to perform a stratospheric balloon experiment in 2019 with the engineering model of the coronagraph. The coronagraph is planned to be installed on the ISS in 2021 for addressing a number of questions (e.g., coronal heating and solar wind acceleration) that are both fundamental and practically important in the physics of the solar corona and of the heliosphere.

Abstract
1. INTRODUCTION
2. SCIENCE CONTEXT AND MOTIVATION
    2.1. Origin of SolarWinds and their Acceleration
    2.2. Coronal Heating
    2.3. MHD Seismology
    2.4. Thermodynamics of CME and OtherCoronal Structures
    2.5. SolarWind, CME Propagation, andSpace Weather Forecast
3. MISSION OVERVIEW
    3.1. Concept
    3.2. System Requirements
    3.3. Work Scope and Roadmap
4. INSTRUMENT AND TESTING
    4.1. Key Techniques
    4.2. Experiments
5. SUMMARY AND OUTLOOK
REFERENCES

• K.-S. Cho(Korea Astronomy and Space Science Institute/University of Science and Technology) Corresponding author
• S.-C. Bong(Korea Astronomy and Space Science Institute)
• S. Choi(Korea Astronomy and Space Science Institute)
• H. Yang(Korea Astronomy and Space Science Institute)
• J. Kim(Korea Astronomy and Space Science Institute)
• J.-H. Baek(Korea Astronomy and Space Science Institute)
• J. Park(Korea Astronomy and Space Science Institute)
• E.-K. Lim(Korea Astronomy and Space Science Institute)
• R.-S. Kim(Korea Astronomy and Space Science Institute)
• S. Kim(Korea Astronomy and Space Science Institute)
• Y.-H. Kim(Korea Astronomy and Space Science Institute)
• Y.-D. Park(Korea Astronomy and Space Science Institute)
• S.W. Clarke(NASA Headquarters)
• J.M. Davila(NASA Goddard Space Flight Center)
• N. Gopalswamy(NASA Goddard Space Flight Center)
• V.M. Nakariakov(University of Warwick)
• B. Li(Sandong University)
• R.F. Pinto(Universite de Toulouse, UPS-OMP)