What is BioSentinel?

Editor’s Note: This article was updated Nov. 21, 2025 shortly after BioSentinel’s mission marked three years of operation in deep space. Astronauts live in a pretty extreme environment aboard the International Space Station. Orbiting about 250 miles above the Earth in the weightlessness of microgravity, they rely on commercial cargo missions about every two months to deliver new […]

NASA Tech to Use Moonlight to Enhance Measurements from Space

NASA will soon launch a one-of-a-kind instrument, called Arcstone, to improve the quality of data from Earth-viewing sensors in orbit. In this technology demonstration, the mission will measure sunlight reflected from the Moon— a technique called lunar calibration. Such measurements of lunar spectral reflectance can ultimately be used to set a high-accuracy, universal standard for […]

NASA Tech to Use Moonlight to Enhance Measurements from Space

NASA will soon launch a one-of-a-kind instrument, called Arcstone, to improve the quality of data from Earth-viewing sensors in orbit. In this technology demonstration, the mission will measure sunlight reflected from the Moon— a technique called lunar calibration. Such measurements of lunar spectral reflectance can ultimately be used to set a high-accuracy, universal standard for […]

Tuning a NASA Instrument: Calibrating MASTER

NASA’s Ames Research Center in Silicon Valley houses a unique laboratory: the Airborne Sensor Facility (ASF). The engineers at the ASF are responsible for building, maintaining, and operating numerous instruments that get deployed on research aircraft, but one of their most important roles is instrument calibration. Think of calibration like tuning a piano between performances: […]