Photophoretic tracers for near-space remote sensing at 30-100 km altitudes

NASA is highlighting a proposed new way to study the upper reaches of the atmosphere, using tiny photophoretic tracers that could float at altitudes between 30 and 100 kilometers for extended periods.

According to a monitored public feed from NASA Breaking News, the concept comes from Benjamin Schafer of Rarified Technologies, Inc. The idea centers on lightweight structures that use sunlight to stay suspended at controlled heights in the thin air of near space. Rather than relying on conventional balloons or other platforms, these tracers would remain aloft through photophoresis, a physical effect that can help support very light objects in rarefied conditions.

The proposal envisions the tracers being remotely observed by satellite-based lidar or radar. That would allow researchers to track their position and behavior from above, offering a potential new tool for sensing atmospheric conditions in a region that is difficult to study with standard methods. NASA’s summary says the tracers are intended to provide a strong signal, unlike natural aerosols that are not designed for such measurements.

The altitude range identified in the feed, 30 to 100 kilometers, spans a part of the atmosphere that sits above the height of most weather systems and below the domain of many satellite observations. That makes it a technically challenging zone for long-duration measurements. If the proposed tracers can perform as described, they could help fill in some of the observational gaps in that layer of the atmosphere.

The concept is tied to NASA’s Space Technology Mission Directorate, which supports technologies aimed at enabling future exploration and scientific capability. Based on the brief description in the feed, the work appears focused on remote sensing rather than propulsion or launch systems, with the tracers serving as a kind of temporary, trackable marker in the upper atmosphere.

NASA’s feed does not provide a timeline, test results, or deployment details in the summary provided, but it frames the idea as a new approach for atmospheric sensing. The goal is to keep the devices suspended for up to months while maintaining a controlled altitude and making them visible to remote sensing instruments.

This report is based on a monitored public feed from NASA Breaking News and reflects the information made available there at the time of publication.

Source: NASA Breaking News - https://www.nasa.gov/directorates/stmd/photophoretic-tracers-for-near-space-remote-sensing-at-30-100-km-altitudes/