• DARPA is working on a program to use microbes as tiny secret agents.
  • The Tellus program would allow the Pentagon to create microbes that could flash signals if a particular enemy activity were detected.
  • Such activities could include troop and ship movements, detecting chemicals or radiation, and more.

The Department of Defense’s research and development division, the Defense Advanced Research Projects Agency (DARPA), is exploring the use of microbes to silently track enemy activities and alert U.S. forces if they’re detected. The Tellus program will enable the design of microbial sensors, invisible spies that would lie dormant and flash a covert signal if adversaries performed a certain activity. These could include tanks crossing a border, a nuclear power plant starting up, and more.

DARPA, the agency behind such hits as RNA vaccines and the Internet, now wants the capability to rapidly develop microbes to track enemy forces. Project Tellus, named after the Roman goddess of the Earth, “seeks to establish the range of chemical and physical signals that microbial devices can detect, environmental conditions they can tolerate, and types of output signals that can be generated,” according to the agency’s press release.

Chemical signals, according to the agency, include toxic or radioactive materials and heavy metal pollutants. Physical signals would include light, electric current, and magnetic fields. An added advantage is that the microbes would be self-powering, requiring no outside power source, or even attention or care.

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Once the microbes detect an activity, they could then output their own chemical or physical signals, including “light, non-toxic organic compounds, or electric current.” The signals would be in plain sight but subtle in nature, just noticeable enough to trip warnings, to prevent the adversary from knowing it is being monitored.

red capped scaber stalk leccinum aurantiacum
An innocent cluster of mushrooms, or genetically-tailored, sensor-informing spies of your every move?
ullstein bild//Getty Images

Candidates for Project Tellus include bacteria, fungi, and microalgae. Microbes can live in a variety of environments, some rather extreme, including outdoors at sea level, underground, underwater, with great variations in temperature, and exposure to heat, cold, and other elements. Not too many spies can brag about that.

How could a working microbial spy alert U.S. forces of enemy activity? At the tactical level, the U.S. might engineer a microbe that exhibited bioluminescence if driven over, seeding it on the border between a U.S. ally and a hostile country. If the hostile country invaded the ally, particularly in a remote location, the bioluminescent microbes would light up the enemy’s trail—a trail that leads directly to the invading force.

Tellus technology could also be useful at the strategic level. Imagine if a country builds a nuclear reactor with the intention of producing fuel for nuclear weapons; it builds the reactor adjacent to a lake, with the intention of using the water to cool the reactor. Using lake water as coolant would increase the temperature of the lake. The Pentagon could seed the lake with microbes that might start pumping out methane if the temperature of the lake rose. The methane emissions could then be detected by remote sensing satellites in space.

california to decommision nuclear power plant
Nuclear power plants such as California’s Diablo Canyon use nearby water sources, and in doing so raising the temperature of the water. Microbial spies could sound the alarm if a rise in temperature indicates the reactor is running.
George Rose//Getty Images

DARPA wants to have prototype “microbial devices” at the end of a 2.5-year development effort, as well as an estimate of how quickly new devices could be designed and deployed.

The idea is to have the capability to create new devices virtually on the fly, to respond to new situations that at present we can’t even imagine. Thanks to DARPA, even the ground America’s adversaries walk on could end up spying on them.

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Kyle Mizokami

Kyle Mizokami is a writer on defense and security issues and has been at Popular Mechanics since 2015. If it involves explosions or projectiles, he's generally in favor of it. Kyle’s articles have appeared at The Daily Beast, U.S. Naval Institute News, The Diplomat, Foreign Policy, Combat Aircraft Monthly, VICE News, and others. He lives in San Francisco.