The sounding rockets will launch at three different times: 45 minutes before, during, and 45 minutes after the peak local eclipse.
NASA is gearing up to launch three sounding rockets during the upcoming total solar eclipse on April 8, 2024. The mission, dubbed Atmospheric Perturbations around Eclipse Path (APEP), aims to unravel the mysteries of how Earth’s upper atmosphere responds when sunlight momentarily dims over a specific region of the planet.
Led by Aroh Barjatya, a distinguished professor of engineering physics at Embry-Riddle Aeronautical University in Florida, the APEP sounding rockets will lift off from NASA’s Wallops Flight Facility in Virginia. These rockets, previously launched and recovered successfully during the October 2023 annular solar eclipse, have been meticulously refurbished with advanced instrumentation for their upcoming mission.
The APEP mission holds significant importance in understanding the disturbances in the ionosphere, a critical region of Earth’s atmosphere situated between 55 to 310 miles (90 to 500 km) above the ground. This electrified zone plays a pivotal role in reflecting and refracting radio signals, thereby influencing satellite communications and various other vital systems.
“The ionosphere’s behaviour during an eclipse is crucial for ensuring the smooth operation of our communication-dependent world,” emphasised Barjatya.
During the April 8 eclipse, the APEP sounding rockets will be launched at three strategic intervals: 45 minutes before, during, and 45 minutes after the peak of the eclipse. These precise timings are essential for capturing comprehensive data on how the sudden disappearance of the Sun impacts the ionosphere, potentially causing disruptions that could affect communications.
Each of the three rockets is expected to reach a maximum altitude of 260 miles (420 km), equipped to measure charged and neutral particle density, as well as surrounding electric and magnetic fields. Additionally, four secondary instruments, resembling the size of two-litre soda bottles, will be ejected from each rocket to enhance data collection.
Collaborating with various research institutions across the United States, the APEP mission will employ a multi-faceted approach to study ionospheric dynamics. Teams from Embry-Riddle, Massachusetts Institute of Technology’s Haystack Observatory, and the Air Force Research Laboratory will deploy high-altitude balloons and operate ground-based radars to complement the data gathered by the sounding rockets.
“When the APEP rockets launched during the 2023 annular solar eclipse, we observed significant perturbations in the ionosphere, particularly affecting radio communications,” remarked Barjatya. “We are eager to relaunch them during the total eclipse to delve deeper into these phenomena.”
With the next total solar eclipse over the contiguous US not expected until 2044, the APEP mission presents a rare and invaluable opportunity for scientists to acquire essential data that could pave the way for enhanced understanding of Earth’s upper atmosphere.
