NASA Outlines CASALS Lidar Path From Airborne Mapping to Space

NASA has published a technology account explaining how its CASALS lidar instrument could progress from airborne mapping toward a possible space mission. The agency reports science-quality data from an earlier flight demonstration and describes planned improvements to swath coverage and onboard processing. The account presents the completed airborne work and the proposed spaceborne capability as different stages of instrument development. NASA report.

Wavelength steering replaces moving mirrors

NASA says CASALS avoids motorized mirrors by steering light through wavelength. A tunable seed laser cycles through multiple discrete wavelengths and passes through a transmission grating. Diffraction bends each pulse to a distinct position across the flight path, creating a continuous swath rather than isolated tracks.

The design removes moving parts, which NASA identifies as heavy and failure-prone. NASA says that change reduces size, weight and power needs and supports reliability in the harsh space environment. The account presents the approach as an instrument design claim, not an independently benchmarked space result. The claim applies to the instrument concept.

Related coverage: related Space reporting.

Detector targets weaker returns

NASA attributes much of CASALS capability to its detector array, which operates at high quantum efficiency. The agency says this means the sensor wastes little returning light and can detect weaker signals. That supports measurements from darker surfaces or through denser vegetation, according to NASA.

NASA describes machine learning as part of the intended capability that will help CASALS adaptively sweep large areas. The planned processing and the existing detector design are distinct elements of the development account. For research teams, it is useful to track the optical measurement results separately from the software improvements the agency says it intends to add.

Related coverage: related Space reporting.

Airborne prototype flew in 2024

NASA says an airborne CASALS prototype flew aboard a B200 King Air aircraft in November 2024. The instrument produced science-quality datasets on its first campaign, exceeding team expectations, according to the agency. John Yorks, principal investigator, praised the engineers and said the system worked well from the first flight. NASA describes the campaign as a first airborne demonstration.

NASA says the instrument can distinguish individual tree branches and subtle elevation changes through fine horizontal resolution. The account places that airborne result within a development programme, with further work intended to prepare the technologies for a future spaceborne version. Our assessment is to evaluate the existing flight datasets and proposed space capability as separate stages.

Related coverage: related Space reporting.

Space path requires more engineering

NASA plans several improvements before creating a space-ready prototype. The team intends to widen the instrument swath and add onboard data processing software. It also aims to fly CASALS again in the ASCENT campaign, scheduled for summer 2027. Those are planned development steps following the earlier airborne campaign.

Yorks says the team is funded to optimize and improve performance and is studying how to mature the airborne technologies for a future spaceborne version. NASA frames the prospect of a space mission conditionally. That places optical engineering and processing capability within the next development phase of the reported programme.

Related coverage: related Space reporting.

What This Means for Practitioners

For research funders and Earth observation buyers, the central question is whether the airborne design can retain its measurement quality after widening the swath and adding onboard processing. Conditional question: what independent tests would verify the detector and mapping claims outside NASA's own campaign?

Our assessment is to follow whether ASCENT proceeds as planned and what the team reports about the swath and processing upgrades. Those milestones would help readers judge progress from the airborne demonstration toward the future platform. Further claims about an operational space mission would require their own supporting evidence.