CODEX

Coronal Diagnostic Experiment

active Mission

Against a black background, the total solar eclipse. It is a black circle surrounded by white, wispy streams of light that flow away from the black circle in every direction.

CODEX is a solar coronagraph installed on the International Space Station to gather important information about the solar wind and how it forms. A coronagraph blocks out the bright light from the Sun to better see details in the Sun's outer atmosphere, or corona. CODEX is a collaboration between NASA Goddard Space Flight Center and the Korea Astronomy and Space Science Institute (KASI) with additional contribution from Italy's National Institute for Astrophysics (INAF).

Mission Type

Coronagraph

FOCUS

The Solar Wind

Launch

Nov. 4, 2024

LOCATION

International Space Station

Illustration of the Sun's corona and solar wind. The Sun's surface is shown with white lines representing magnetic field lines extending into its atmosphere, labeled "Corona" and "Solar Wind." The background in shades of blue simulates outer space, highlighting the temperature difference.

An artist's concept of the solar corona as it transitions into the solar wind.

NASA

CODEX has two key goals:

To understand what heats the solar wind to a million degrees hotter than the Sun’s surface and sends it streaming out at almost a million miles per hour.
To test models that show this heating and acceleration region.

CODEX's research will help scientists understand the heating and acceleration of the solar wind, the constant stream of particles and magnetic fields that flow off of the Sun. While traditional coronagraphs look at the density of the solar wind in this area, CODEX will observe the temperature and velocity of the solar wind in addition to the density. This information will provide new insight that enables researchers to better understand where the energy that affects the solar wind comes from.

The coronagraph will also build upon research from other missions, like Parker Solar Probe. CODEX will look at the solar wind much closer to the solar surface, while Parker Solar Probe samples it a little farther out. By comparing these findings, scientists can better understand the full picture of that region and how the solar wind changes as it travels farther from the Sun.

Scientists will also compare results with spacecraft that have solar coronagraphs, too, like the ESA (European Space Agency) and NASA Solar Orbiter mission and NASA’s future Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission.

The International Space Station takes up the top two-thirds of the photograph. It has a long cylindrical body, with various white and silver panels, boxes, and modules extending from it. There are two sets of solar panels on the left and right sides, extending above and below the station. Earth takes up the bottom third of the image.

The International Space Station appears in this photograph taken by Expedition 56 crew members from a Soyuz spacecraft after undocking on Oct. 4, 2018.

NASA