NASA is planning to study a little-understood portion of Earth’s atmosphere this year, launching two spacecraft that will monitor how our ionosphere interacts with space.

The first of the two missions is called GOLD, or the Global-scale Observations of the Limb and Disk, which will be launching on January 25 on an Ariane 5 rocket from Kourou, French Guiana. Later this year the second part of the mission – the Ionospheric Connection Explorer (ICON) – will launch.

The plan is to study how the solar wind and other space weather interact with Earth’s upper atmosphere, the ionosphere, and thermosphere, at an altitude of around 97 kilometers (60 miles). This region is in constant flux as it is pushed and pulled by conditions on Earth and in space.

"There are huge scientific modeling efforts associated with both of these missions," said Sarah Jones, GOLD mission scientist at NASA's Goddard Space Flight Center in Maryland, in a statement.

"We already have models that are filled with really good science, but these new measurements will lead to a better understanding of the physics in the models.”

GOLD will be placed in a geostationary orbit 35,000 kilometers (22,000 miles) above Earth’s surface. Here, it will have a continual view of Earth and its outer atmosphere. It will get a complete view of the ionosphere and upper atmosphere every half an hour, giving us large-scale measurements of the region.

Then, later in 2018, ICON will be launched to get a more close-up view. Orbiting at an altitude of 565 kilometers (350 miles), ICON will repeatedly pass through the field of view of GOLD, so that their data can overlap.

It’s hoped that the missions will help us see how hurricanes and geomagnetic storms affect the upper atmosphere, in addition to solar wind. Scientists are also keen to see what effect El Niño has too, while tropical cyclones may also cause some changes.

GOLD will also monitor disruptions in the ionosphere at night, in the form of bubbles of charged gas that can interfere with radio communications as a result of geomagnetic storms. ICON, meanwhile, will study how gases in the upper atmosphere interact.

"We used to think only solar wind could affect the ionosphere, and only the lower atmosphere was affected by terrestrial weather," said Doug Rowland, ICON mission scientist at NASA Goddard, in the statement.

Now, thanks to this mission, we’re going to find out how both Earth and space weather can shape our upper atmosphere.