Dr. Bless and Dr. Iskander at NYU Transparent Soils Lab
When designing an investigation for unexploded ordnance (UXO) at formerly used defense sites, one of the first questions asked is “how deep could the munitions have penetrated into the subsurface?” This is not just a theoretical question, it carries serious implications for cleanup efficiency, costs, and safety. Until recently, that question generally remained unanswered. At the intersection of this complex problem stand two researchers with distinctly different backgrounds who both work at NYU Tandon School of Engineering: Dr. Stephan Bless, a ballistics physicist, and Dr. Magued Iskander, a geotechnical engineer. Their SERDP-funded collaboration represents significant progress in addressing one of the most persistent challenges in site-specific subsurface prediction, a journey that continues to evolve.
Two Distinct Paths to Science
Before their work on UXO prediction, Bless and Iskander had already established themselves in their respective fields through very different journeys.
"I had a degree in geophysics from MIT," Bless said. His career took him through rock mechanics to armor development and eventually to electric guns. "I worked in a laboratory developing electric guns," he said. "The way that armor works is to destabilize projectiles so they don't go into a straight line. That is also what happens in soil. I understood how materials can deflect penetrators.”
Iskander's path to geotechnical engineering came through an unexpected detour. "Shortly after getting my BS in Civil Engineering, I was working in a structural engineering office, designing a 22-story building. It was repetitive work of designing one column after another, so I wrote a software to do my work, and recruited an overqualified receptionist to enter the data for me" he said. "My supervisor said “you are not cut out to be a structural engineer, I'm sending you to geotechnical division where no two projects are the same.” What could have been an insult became the gateway to his life's work. "Geotechnical engineering, I realized, is one of the most creative parts of engineering."
A Partnership Forms
Long before SERDP entered the picture, Bless and Iskander had found common ground in their complementary expertise.
"Stephan and I were introduced to each other by a Defense Threat Reduction Agency (DTRA) grant manager," Iskander said. " He heard about the technology I invented, transparent soils, and requested that I present for his group. When he found out that I had no prior DoW experience he introduced me to Professor Bless who was well versed in DoW work. We have done important work together which led to many papers, and we also wrote a book together."
This collaboration has endured for approximately 15 years. "It's been one of the longest relationships I've had outside of my family," said Iskander. "It has been mutually beneficial and intellectually stimulating. He's a scientist, I'm an engineer, he's a physicist, I'm a geo-technical engineer. The marriage of the two of us leads to practical engineering solutions that are science-based."
Over the years, the project has also trained a new generation of researchers. Several of Dr. Iskander’s former students have advanced the work in their own careers, one, Dr. Mehdi Omidvar, became a collaborator on subsequent SERDP projects, while two others have gone on to university positions, and scores are employed in industry.
A New Venture: Tackling the UXO Challenge
When approaching the UXO depth prediction challenge, Bless and Iskander were uniquely positioned to tackle it. "Stephan worked with these models for a long time," said Iskander. "DTRA and SERDP were interested because I researched synthetic soils that you can see through. You can see the deceleration."
Their complementary perspectives allowed them to reframe the problem in a more productive way. "The strategy is how can we make this better," Iskander said. "Let's lean on what geotechnologists usually do. As geotechnical engineers, we are comfortable dealing with site variability."
Rather than asking "how deep could UXO possibly be?" they focused on determining what depths were most likely under specific conditions. This shift in perspective allowed them to develop more useful predictions for remediation teams.
Their initial project established the GeoPoncelet model, which relates penetration resistance to cone-penetrometer test (CPT) measurements. This semi-empirical approach combines physics-based modeling with practical engineering applications.
"For both of us, this project has been an exciting collaboration activity; it is the epitome of an interdisciplinary research project," said Bless. “We marry two scales: the microscopic scale that determines how hard it is to penetrate a soil, with average properties that are the only practical way to work in geo mechanics. You have to deal with average properties.”
Ongoing Progress and Future Directions
Their work continues to evolve. Their newer project extends their research to underwater environments, developing a model for predicting munitions burial in saturated soils with water overlays.
"We began with the most ideal situation, and now we are adding real-world complications," said Bless, highlighting how their research has progressed from straightforward scenarios to more complex real-world conditions.
The team is now working on an active approach to conduct real field experiments, further validating their models under authentic conditions. By 2027, when the current project concludes, they aim to provide a means of making site-specific depth of burial predictions for both terrestrial and shallow water environments. Such a tool could ultimately help DoW teams prioritize resources, accelerate cleanups, and reduce risk to both workers and nearby communities.
The Excitement of the Unsolved
What drives these researchers isn't just the technical challenge, it's the historical significance of the problem they're addressing.
"This problem has been around since the 19th century,” said Bless. "It's satisfying to work on something that has been around for a long time and has not been solved and yet serves an ever more urgent need both within our country, and in other parts of the world as well.”
Iskander agrees: "We become professors because we want to tackle the hardest problems, the unsolved ones. That is what makes this work so exciting."
As their work continues to develop over the coming years, the progress made by Bless and Iskander offers hope for more effective UXO remediation strategies. While the challenge isn't fully solved, their collaboration demonstrates how bringing together different scientific perspectives can make significant headway on problems that once seemed intractable.
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About SERDP & ESTCP
The Strategic Environmental Research and Development Program (SERDP) and the Environmental Security Technology Certification Program (ESTCP) develop and demonstrate innovative, scalable technologies that enhance military readiness, improve warfighter capabilities, and strengthen defense infrastructure. SERDP invests in basic and applied research to secure military installations, and ESTCP puts innovations to the test, fielding real-world solutions that enhance military operations. The programs report to the Deputy Assistant Secretary of Defense for Energy Resilience & Optimization headquartered at the Pentagon. For more information, visit https://serdp-estcp.mil.
