VICKSBURG, Miss. ― If you’re a Soldier entering a cave on a military operation overseas, a venomous snake or a rabid bat can really ruin your day.
A multidisciplinary team at the U.S. Army Engineer Research and Development Center-Environmental Laboratory (ERDC-EL) is currently cataloguing the naturally occurring threats that Soldiers encounter in such situations, with the goal of eventually developing an unmanned solution.
“We’re developing sensors that will eventually be attached to unmanned vehicles that enter subterranean environments ahead of forces to detect the biological threats and provide our Soldiers some stand-off detection,” said Maj. Derrek Hopper, team lead. “And we’re talking about naturally occurring biological threats, because the chemical, biological, radiological, nuclear and explosives community already focuses on the weaponized stuff like anthrax. Right now, we’re looking at caves or tunnel systems and exploring what we can detect that grows there naturally or that has moved in.”
“It’s a $14.1-million-dollar project over the next five years, and it just started in fiscal year 2021; the first task was getting the sensors we ordered, developing other sensors and doing laboratory assessments for them all,” Hopper said.
Hopper described how military operations are starting to move underground.
“We’re starting to see this in Syria, all over the world, really — anytime one group fights another group that has superior sensing technologies, especially optical sensing technologies that are overhead, something that’s satellite- or air-based, it’s easier just to move underground and hide,” he said.
The naturally occurring threats in these subterranean environments can be divided into those that are either macroscopic, like arachnids, reptiles or mammals; or microscopic, such as the threat agents that spread between animals and people and are bacterial, fungal or viral in origin. COVID-19 would be an example of a viral microscopic threat agent.
Dr. Eric Britzke, an ERDC-EL research wildlife biologist and the lead for the macroscopic team, will soon be travelling to subterranean locations around the U.S. with team members to document the presence of both types of natural threats in these environments.
“We’re sampling for everything, and what we’re trying to do from a macroscopic standpoint is use thermal cameras as our first line of detection; we’re basically looking and saying ‘what can we detect with a thermal camera?’” Britzke said. “Our project is also designed so there will be additional multiple sensor options, so the users can choose what they’re interested in detecting and pick the appropriate sensor package.”
The team will be sampling natural cave systems representing different microclimates, including the Mammoth Cave system in Kentucky and a dry cave system out west. They will also be collecting samples in a variety of engineered subterranean environments, such as old mining caves located near 29 Palms in California. As the research project progresses, the team will assess how the detection system performs at various subterranean locations outside the U.S.
“Natural cave systems are especially challenging to sample due to their complex 3D-structure, significant surface area, microhabitats and variable environmental conditions,” said Dr. Karl Indest, a research microbiologist with ERDC-EL and lead for the microscopic team.
“We’re looking for macroscopic species that we know may transmit some diseases: bats and rats, for example,” Hopper said. “Obviously, there are some inherent threats with reptiles like snakes, which can interfere with military operations, especially if you’re trying to be quiet about something and there’s a snake ― should you just shoot it and move on, or do you have to turn around and go back?”
Indest’s team is now evaluating commercial off-the-shelf technologies for rapid detection of a variety of microscopic species. Once team members determine they can detect these species with the sensors, they will use the data the macroscopic team collects to narrow the focus and integrate the two lines of research.
Britzke said it’s important to understand that the project team is striving to make one holistic effort, rather than one project with two different parts. That way, the sensors can eventually do things like detect certain macroscopic species groups that can help narrow down the microscopic species list.
“If we don’t find bats in a cave, let’s say, we can just ignore all the microscopic threat species that bats are vectors, or carriers, for,” Britzke said.
“In a subterranean environment, you don’t own it, so it’s contested in a conflict-type scenario ― this is why the unmanned platform is incredibly important to this particular type of research; the idea is we don’t want to send a person in there with a sensor to determine what may be around,” Hopper said.