NASA’s Innovative Lunar Observation Mission

In March 2025, under the glow of a waxing Moon, NASA’s ER-2 aircraft embarked on a revolutionary mission, transforming into a lunar observatory high above California’s skies. Operated from NASA’s Armstrong Flight Research Center, these nighttime flights were pivotal for the Airborne Lunar Spectral Irradiance project, commonly known as air-LUSI.

Harnessing Moonlight for Earth Science

Equipped with a state-of-the-art spectroradiometer, the air-LUSI instrument captured moonlight across various wavelengths and phases. By analyzing the Sun’s reflective light from the Moon’s surface, researchers are able to calibrate orbiting Earth monitoring satellites with unmatched precision. According to Kevin Turpie, the principal investigator at NASA’s Goddard Space Flight Center, the Moon serves as an essential benchmark, allowing satellites to reliably measure vital Earth processes.

Sky-High Measurements for Unrivaled Clarity

Flying at an altitude of 70,000 feet, the ER-2 aircraft soared above 95% of the Earth's atmosphere, granting researchers access to extraordinarily clear data. This altitude minimizes atmospheric interference, resulting in measurements of exceptional purity. Kelsey Bisson, NASA program scientist, emphasized that air-LUSI has achieved the most accurate lunar measurements to date, which could reshape our understanding of Earth's weather patterns and ecosystems.

Revolutionizing Calibration and Cost Efficiency

By providing high-precision calibration for satellites, air-LUSI significantly reduces the necessity for expensive onboard reference devices. Not only does this enhance data quality, but it also holds the promise of lowering overall mission costs, making space exploration more economical.

A Collaborative International Effort

This groundbreaking project is a collective initiative involving NASA, the National Institute of Standards and Technology (NIST), the U.S. Geological Survey, the University of Maryland Baltimore County, and Canada’s McMaster University. The latter played a critical role by developing advanced hardware for the mission, including an Autonomous Robotic Telescope Mount and the innovative High-Altitude Aircraft Mounted Robotic (HAAMR) telescope mount. These technologies allowed for precise lunar tracking during the flights.

A New Era for Airborne Lunar Observations

Andrew Gadsden, an associate professor at McMaster and co-investigator on the project, highlighted the exciting collaborative engineering and scientific efforts between American and Canadian teams. With the successful integration of the HAAMR system, we are stepping into a new era of airborne lunar observation, enabling the highest accuracy measurements of lunar light to enhance Earth observation capabilities.