NASA is preparing to launch three sounding rockets during the solar eclipse on April 8, 2024. The “Atmospheric Perturbations of the Eclipse Orbit” (APEP) mission aims to uncover mysteries about the response of the upper layers of the Earth’s atmosphere to temporary dimming of sunlight.

APEP sounding rockets, led by Aroh Barjatya, Professor of Engineering Physics at Embry-Riddle Aeronautical University in Florida, will launch from NASA’s Wallops, Virginia facility. These rockets were repaired and upgraded following a successful mission during the October 2023 solar eclipse.

The APEP mission is of great importance in understanding the perturbations occurring in the ionosphere, the region of the Earth’s atmosphere between 90 and 500 km. The ionosphere plays an important role in reflecting and refracting radio signals, thus affecting satellite communications.

During the eclipse on April 8, APEP probes will be launched at three strategic intervals: 45 minutes before, during and 45 minutes after the eclipse’s peak. These intervals are calculated to obtain complete data on how the disappearance of the Sun affects the ionosphere and can cause communications failures.

Each of the three rockets is expected to reach a maximum altitude of 420 kilometers and will be equipped to measure the density of charged and neutral particles, as well as the surrounding electric and magnetic fields. Additionally, four two-liter soda bottle-sized devices will be launched from each rocket to improve data collection.

The APEP mission, in collaboration with several research institutes in the United States, will use a multifaceted approach to study the dynamics of the ionosphere. Teams from Embry-Riddle Haystack Observatory, MIT, and the Air Force Research Laboratory will deploy high-altitude balloons and use ground-based radars to supplement data from sounding rockets.

“When APEP rockets were launched during the 2023 annular solar eclipse, we observed significant perturbations in the ionosphere that affected radio communications,” Barjatya said. “We will launch them during the upcoming total eclipse to study this phenomenon more deeply.”

The APEP mission, along with the next total solar eclipse over the United States, which will not occur until 2044, offers scientists a rare opportunity to obtain important data that will help better study Earth’s upper atmosphere.