NASA CASALS lidar technology uses a rapidly tuned laser to capture broad three-dimensional views of forests and terrain without a conventional scanning mirror, according to a NASA Science update published Oct. 21, 2026. The research team is developing the instrument as a possible future approach to space-based Earth observation.
A prototype has already flown on a NASA B200 King Air research aircraft, but the instrument has not been launched into orbit. NASA says it collected scientific data during a November 2024 airborne campaign, and the team aims to carry out another flight series in summer 2027.
The instrument addresses a weakness in some satellite lidar systems: they sample narrow tracks, leaving unmapped gaps between measurements. CASALS is designed to collect a continuous swath, potentially giving researchers a more complete picture of vegetation and topography.
Table of Contents
How NASA CASALS Lidar Steers 256 Beams
NASA explains that the Concurrent Artificially-intelligent Spectrometry Lidar System, known as CASALS, uses a tunable seed laser near 1,040 nanometers. It cycles through 256 wavelengths, sending pulses through a diffraction grating that redirects the light at different angles. The shifting wavelengths perform the scanning rather than a moving mirror.
The NASA Science technology report says the method can collect a continuous three-dimensional strip across the ground below the aircraft. Removing bulky mechanical components is intended to reduce instrument size, weight and power demands. It may also improve reliability by reducing reliance on moving optical parts.
This does not mean that CASALS already maps the whole planet or that every wavelength produces a separate satellite image. The 256 wavelengths are part of a laser-steering mechanism. The scientific output depends on detecting reflected light from ground and vegetation at many positions within the instrument’s field of view.
Airborne Results Show Forest and Terrain Detail
During the November 2024 flight campaign, NASA placed a prototype aboard a B200 King Air. The agency says the instrument delivered science-quality measurements on its first airborne trial. Flights over the Great Cypress Swamp in Delaware included observations of the tree canopy, the ground and vegetation closer to the surface.
NASA reports approximately 22-centimeter horizontal resolution during airborne measurements from an altitude of roughly five kilometers. That figure describes the reported experimental performance under those conditions. It is not a published guarantee of equivalent resolution from a future satellite operating much farther above Earth.
The detector system is another part of the project. NASA says its sensor has about 80% quantum efficiency, a measure of how effectively returning photons are converted into usable signals. Higher sensitivity is valuable for weak reflections and for studying complicated surfaces, including layered plant growth.
Machine Learning and the Path Toward Space
The CASALS research concept combines optical engineering with onboard or subsequent data analysis. NASA describes machine learning as part of its longer-term approach to creating more complete three-dimensional maps of the planet. Those capabilities could help with measurements of forest structure and subtle differences in terrain elevation.
For now, the agency says researchers are working to widen the instrument’s swath and add onboard processing software before developing a space-ready prototype. That work is essential because aircraft experiments and satellite missions have different requirements for radiation tolerance, power, thermal control and data transmission.
A separate TAD report about Norway’s 2027 flight demonstrations also involves an aircraft-based research campaign, although for hybrid-electric aviation rather than Earth-observation instruments. The projects serve different scientific aims; neither announcement establishes that a new satellite mission has entered service.
FAQ: NASA CASALS lidar
Is NASA CASALS lidar operating in orbit?
No. NASA describes an airborne research prototype and future work toward an instrument suitable for a space mission.
How does CASALS scan without a moving mirror?
It switches among 256 laser wavelengths and uses a diffraction grating to send successive pulses in different directions.
When is the next planned flight test?
NASA says the team aims to fly CASALS again in the summer 2027 ASCENT airborne campaign.
Looking Ahead
NASA CASALS lidar work is expected to continue with a planned summer 2027 ASCENT flight campaign. Researchers intend to improve swath width and onboard processing before assessing a future orbital instrument. NASA has not announced a launch date or an approved satellite mission carrying CASALS.
Sources
