Photo credit: www.nasa.gov

NASA’s Groundbreaking Airborne Lunar Spectral Irradiance Mission

In a remarkable intersection of aerospace engineering and lunar research, NASA recently conducted a series of night flights using the ER-2 science aircraft. This initiative, which took place in March 2025 over the Armstrong Flight Research Center in California, aimed to gather vital data as the Moon appeared more prominent in the night sky. These flights transformed the high-altitude aircraft into a unique lunar observatory.

The mission, known as the Airborne Lunar Spectral Irradiance (air-LUSI), focused on observing the Moon through its various phases. Specifically, it measured the sunlight that is reflected off the lunar surface, capturing data across a range of wavelengths. This approach not only enhances our understanding of the Moon but also allows for its use as a calibration standard for sensors that monitor Earth.

According to Kevin Turpie, the principal investigator for the air-LUSI mission and a researcher at NASA’s Goddard Space Flight Center, “As an absolute reference, the Moon also becomes the perfect benchmark for satellites to consistently and accurately measure processes on Earth.” This capability is essential in improving various measurements, such as those related to weather conditions, plant growth, and oceanic behaviors.

The ER-2 operates in the lower stratosphere, where it can fly at altitudes close to 70,000 feet. This height ensures that the data collected by the air-LUSI instrument are of exceptional quality, largely because the aircraft operates above 95% of the atmospheric interference caused by lower-altitude pollutants and particulates.

Kelsey Bisson, a NASA program scientist involved in the air-LUSI mission, remarked on the significance of the data: “To date, air-LUSI measurements of the Moon are the most accurate ever made. Air-LUSI data can advance our ability to understand the Earth and our weather, and they provide a new way to calibrate satellites that can result in cost savings.”

The implications of this data are vast, particularly with regard to enhancing the reliability of satellite observations and Earth monitoring systems. Using air-LUSI data helps minimize the necessity for onboard reference instruments, potentially reducing the overall costs associated with satellite operations.

A collaboration of prestigious institutions, the air-LUSI project involves experts from NASA, the National Institute of Standards and Technology, the U.S. Geological Survey, the University of Maryland Baltimore County, and McMaster University in Ontario, Canada. Andrew Gadsden, co-investigator on the air-LUSI project and an associate professor at McMaster University, emphasized the significance of this transnational effort. He explained, “The collective effort of the American and Canadian team members offers an opportunity for truly exciting engineering and science collaboration.”

The McMaster team played a crucial role, developing the Autonomous Robotic Telescope Mount Instrument System and the High-Altitude Aircraft Mounted Robotic (HAAMR) telescope mount, integral to the air-LUSI setup. During the March flights, the HAAMR telescope was used for the first time, significantly contributing to what co-investigator John Woodward IV described as “the highest accuracy measurements” of moonlight. This advancement represents an important step forward in enhancing Earth observation technology through airborne lunar research.

Source
www.nasa.gov