Award-Winning NASA Camera Revolutionizes How We See the Invisible

Imagine you are trying to photograph the wind. It’s similar to what NASA engineers faced in a recent effort to study how air moves around planes, rockets and other types of aerospace vehicles. Air is invisible, but our understanding of how it flows is crucial to building better, safer planes.

For 80 years, researchers have used a technique called “focused Schlieren imaging.” Think of it as a special camera system that can “see” air movement by detecting tiny changes in its density. It’s the same effect that lets you see heat waves rising over hot pavement on a sunny day – but much more accurately.

The SAFS (Self-Aligned Focusing Schlieren) system is a game changer. It is a compact, inexpensive and easy-to-use viewing tool that is less complex than traditional focusing systems.

“What makes this breakthrough compelling is the ripple effect,” said NASA’s Brett Bathel, who invented SAFS alongside fellow engineer Joshua Weisberger at the agency’s Langley Research Center in Hampton, Virginia. “When researchers can observe and understand aerial movement in a way that was previously difficult to achieve, it leads to better aircraft designs and safer flights for everyone.”

Moving from legacy systems to SAFS in wind tunnels and other specialized research environments allows aerospace engineers to more efficiently collect high-speed flow visualization data, with less facility downtime and reduced costs. For the aviation industry, this opens the door to new discoveries, potentially revolutionizing the way we design everything from commercial airliners to spacecraft.

With SAFS in its toolbox, NASA is also better positioned to achieve its mission goals related to efficiency and safety in aviation and space. Researchers use SAFS to capture flow separation on the High Lift Common Research Model, a tool to improve the accuracy with which we can predict the takeoff and landing performance of new aircraft. And it helps them study shock cell structures – diamond shapes that form in exhaust plumes – for the Space Launch System model.

NASA technology is already used around the world and adopted by more than 50 institutions in more than 8 countries, from Notre Dame to the University of Liverpool. Companies continue to license the technology and commercial versions come to market.

The impact was so great that NASA researchers won numerous awards. R&D World has awarded SAFS a place in its R&D 100 Awards 2025, selected by a panel of global experts.

NASA also named SAFS the 2025 NASA Government Invention of the Year, the highest award the agency bestows on breakthrough technologies.

To understand why SAFS is so important, you need to know what researchers were working on before.

The old setup of targeted Schlieren imaging required researchers to have access to both sides of what they were testing. They had to install separate light source grids on each side and align them perfectly with each other. It’s the equivalent of lining up two window screens on opposite sides of a room so that their patterns match exactly.

Setting up one of these systems could take weeks of careful adjustments, what if someone accidentally bumps the system or has to make an adjustment? Start again.

Enter the SAFS system. In 2020, NASA researchers asked a crucial question: What would happen if they could eliminate all this complexity using the properties of light itself?

The solution? Polarization of light. Your polarized sunglasses work by filtering light in specific directions. The SAFS system does something similar, using light polarization to create the same effect as the old, cumbersome dual-grid setup. The SAFS system only requires access to one side of the object you are testing. And, instead of needing two separate grids that need to be perfectly aligned, it uses a single grid that does double duty.

What used to take weeks to set up now takes just minutes. Need to make adjustments? No problem. The SAFS system can change sensitivity, change its field of view, or adjust focus on the fly. The system is compact and insensitive to vibrations (goodbye, starting all over again because someone passed by).

Sometimes revolutionary advances come not from increased complexity, but from finding new, creative solutions to age-old problems. SAFS is proof that there is always room for innovation – and it is already leaving its mark on the world.

Work on SAFS was supported by NASA’s Aeroscience Evaluation and Test Capabilities Portfolio Office and the Transformational Tools and Technologies project, which aims to develop new computational tools to help predict aircraft performance. The project is part of NASA’s Transformative Aeronautics Concepts program, under its Aeronautics Research Mission Directorate.