U.S. Naval Research Laboratory (NRL) Senior Scientist for Intense Particle Beams & Plasma Processes, Gurudas Ganguli, Ph.D., pioneered and directed an experiment that has
NRL’s Space Measurement of A Rocket-released Turbulence (SMART) sounding rocket experiment, launched from Wake Island on February 12, stands as a landmark achievement, successfully bridging the gap between theoretical physics and the natural laboratory of space.
The Challenge
Our modern world relies on satellites for communication, navigation, observational science, and much more. Adverse space weather is a growing concern for these spacecraft.
“Space weather for spacecraft is like atmospheric weather for airplanes; both can create dangerous conditions that affect performance and safety,” Ganguli said. “Unlike Earth’s atmosphere, space is filled with an electrically charged gas, plasma, whose turbulent behavior can pose dangerous conditions for spacecraft.”
To understand this environment, the NRL team conducted the SMART sounding rocket experiment, designed to study how plasma turbulence forms and how it evolves through space.
The Launch
Shortly after dusk in the North Pacific Ocean, a single four-stage sounding rocket carrying a two-part payload propelled into the darkness to an altitude of 537 kilometers. Once beyond the Earth’s atmosphere, the two payloads separated. The first released a high-speed cloud of neutral vapor aimed at the second, which was equipped with a suite of sensors to collect data.
The experiment lit up the sky with an aurora-themed spectacle. As the released vapor was illuminated by sunlight, the neutral atoms glowed vibrant green while the ions created a blue and purple hue.
As the sunlight ionized the neutral atoms, they became confined by Earth’s magnetic field, triggering electrostatic plasma turbulence.
The Discovery
The SMART team had achieved their goal – the identification and characterization of a process never-before seen in space. They had successfully created strong plasma waves and turbulence in the surrounding space environment.
“For the first time, we are inducing turbulence in space and studying its evolution,” Ganguli said. “It has never been confirmed in a real-world environment and had only been demonstrated through theoretical models and laboratory tests.”
That turbulence caused a secondary reaction: the nonlinear conversion of electrostatic turbulence into electromagnetic “whistler” waves, which can travel far beyond the release region and carry energy deeper into space.
These whistler waves propagated away from the immediate experiment site. Their discovery was made possible by the payload's instruments, which measured the fluctuating electric and magnetic fields of the waves and their frequencies. The findings were supplemented by ground-based sensors that measured the ion cloud's size and optical intensity while detecting the far-field propagation of the whistler waves.
“This experiment was a significant milestone in the understanding of a very difficult problem that affects everybody who is reliant on space,” said SMART Program Manager and NRL Dynamics and Control Systems Branch Head, Christopher Netwall. “NRL's Plasma Physics team has been studying this for a long time, and this successful test was the culmination of a lot of hard work over many years. I am proud of the whole team for their dedication to this program through all its highs and lows, and especially happy for Dr. Ganguli for this achievement.”
From liftoff to the final measurements, the entire experiment lasted about 10 minutes. The small amount of vapor released dispersed quickly and safely recombined with atmospheric elements. While scientists have conducted vapor release experiments since the 1960s, the SMART mission was unique in its scientific objectives and sophisticated instrumentation.
NRL scientists partnered with several agencies to accomplish this task, including the following:
- Naval Surface Warfare Center Port Hueneme Division White Sands Detachment
- Naval Surface Warfare Center Indian Head Division
- Naval Surface Warfare Center Dahlgren Division
- Pacific Air Forces Regional Support Center, Wake Island Detachment
- U.S. Army Space and Missile Defense Command Reagan Test Site
- U.S. Space Force 19th Space Defense Squadron
- Missile Defense Agency Test Directorate
- NASA-Goddard Space Flight Center
- University of Alaska Fairbanks
- University of Washington
About the U.S. Naval Research Laboratory
NRL is a scientific and engineering command dedicated to research that drives innovative advances for the U.S. Navy and Marine Corps from the seafloor to space and in the information domain. NRL, located in Washington, D.C. with major field sites in Stennis Space Center, Mississippi; Key West, Florida; Monterey, and California.
NRL offers several mechanisms for collaborating with the broader scientific community, within and outside of the Federal government. These include Cooperative Research and Development Agreements (CRADAs), LP-CRADAs, Educational Partnership Agreements, agreements under the authority of 10 USC 4892, licensing agreements, FAR contracts, and other applicable agreements.
For more information, contact NRL Corporate Communications at
NRLPAO@us.navy.mil.
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