NASA AWE Instrument Concludes Mission on International Space Station

The National Aeronautics and Space Administration's (NASA) Atmospheric Waves Experiment (AWE) instrument has completed its data collection mission. Ground controllers powered down the instrument on May 21, marking the scheduled end of its operational phase. AWE was installed on the exterior of the International Space Station (ISS) in November 2023.

The instrument was designed to study atmospheric gravity waves. These waves are large ripples in the atmosphere. They are caused by strong winds over mountains or by severe weather events like tornadoes, thunderstorms, and hurricanes. AWE observed these waves in colorful bands of light in Earth's atmosphere, known as airglow.

AWE investigated how atmospheric gravity waves travel upward into space. This propagation contributes to space weather. Space weather conditions can disrupt satellites and interfere with navigation and communication signals. The mission aimed to understand how Earth's weather influences the space environment.

During its 30-month tenure on the ISS, AWE captured more than 80 million nighttime infrared images. It observed atmospheric gravity waves from numerous extreme weather events. These included a tornado outbreak in the central United States in May 2024 and Hurricane Helene impacting the Gulf Coast of Florida in September 2024. These observations showed variations in gravity waves produced by different storm types.

Understanding variations in plasma density in Earth's upper atmosphere is crucial. Atmospheric gravity waves instigate these variations. Such changes can disrupt radio signals, affecting navigation, timing, and communication systems. A recent study in the *Journal of Geophysical Research: Atmospheres* indicated that gravity waves with horizontal wavelengths of 30 to 300 kilometers most influence the upper atmosphere. AWE was specifically designed to measure these wavelengths.

With data collection complete, the AWE instrument will be removed from the ISS. It will be replaced by the Calibration Absolute Radiance and Refractivity Observatory Pathfinder (CLARREO Pathfinder). CLARREO Pathfinder will measure sunlight reflected by Earth and the Moon. The AWE instrument will then be loaded into a SpaceX Dragon cargo spacecraft for deorbit and atmospheric re-entry. All AWE observations will be made publicly available for scientific research.