Grunt

By Mary Roach

9 min read

Why does it matter? Because the people who change the odds of survival in war never make the news.

Assume you know what military research looks like: missiles, armor, things with threatening acronyms. Now picture a government scientist whose armpit sweat is so revolting to blacktip sharks that his colleagues debate weaponizing it. Picture maggots cleared by the FDA to clean wounds that surgery and antibiotics can't close, cadavers in orange Lycra detonated to improve seat cushions in armored vehicles, a multi-year federal project to develop a stench weapon that smells pleasant on the first inhale and catastrophic on the second. Mary Roach — who has previously investigated cadavers and space medicine — spent two years with these researchers, and Grunt is what she found: the other military, not the one that fights but the one that figures out, with rigorous and sometimes ungainly precision, how to keep a human body functional at the exact edge of what bodies can survive. These researchers never make the news. After reading this book, you'll notice their absence every time you do.

The Weirdest Military Research Is Usually the Most Important

Malcolm Kelley had eight turkey vultures wearing radio transmitters, and from the data streaming back to him, he was beginning to solve a problem the US Air Force had been losing sleep over for decades. Turkey vultures caused only one percent of Air Force birdstrikes but were responsible for forty percent of the damage — heavy raptors striking cockpit glass with ruinous force. Mapping their flight habits against scheduling data, Kelley calculated that simply understanding where the birds flew could save the Air Force five million dollars a year, plus an unknown number of pilots.

Which brings up an obvious question: what does the Air Force test cockpit glass against when designing it to survive a bird strike? The answer is a domestic chicken, fired from a sixty-foot barrel at over 400 miles per hour.

A live bird hits with wings spread and legs trailing; a carcass hits like a compact slug. At 0.92 grams per cubic centimeter, a domestic chicken is about a third denser than a herring gull — the worst-case mass in the tightest package. You test for the worst case. Three thousand birds collide with Air Force jets every year, costing fifty to eighty million dollars in damage and occasionally a pilot's life. The chicken gun was built because it was the right answer — it only sounds absurd until you know what the question actually requires.

Grunt is full of research that looks like this: someone took the question seriously enough to do the thing that seemed absurd, and it turned out to matter enormously.

Decades of Preventable Blast Injuries Happened Because We Were Testing With the Wrong Dummy

Nicole Brockhoff watches the footage in slow motion. The film runs at ten thousand frames per second, slowed until the half-second event becomes something you can examine. Two figures sit in seats above a buried explosive: a cadaver and the Hybrid III, the automotive crash test dummy the Army had been using to evaluate whether its new mine-resistant vehicles would keep soldiers alive. When the charge fires, the cadaver rocks with the blast — arms thrown wide, lower legs lifting, head lurching forward. The Hybrid III barely moves. Its thighs rise a third as high. Its ankles almost don't flex.

Brockhoff, a Pentagon personnel vulnerability analyst, told her colleagues this didn't seem like enough. The Hybrid III was built for front-back and side-to-side impacts: head-on collisions and T-bone crashes. IEDs in Afghanistan came from below, buried in the center of roads. The axis of force ran heel to skull, and the dummy had almost no instrumentation along it. The Army had been approving seat designs and selecting vehicles using an instrument built for the wrong problem.

What that gap produced: an underbody blast can compress a soldier's spine by two inches. The heel contains a fat pad (dense fibrous tissue unique to the human heel, which keeps the bone from working through the skin) that underbody blast destroys regularly, with nothing adequate to replace it. A review of forty such cases found a 45 percent amputation rate. The bone could often be repaired. The pad couldn't, and once it was gone, standing on that heel became agonizing enough that some soldiers preferred to lose the foot. A silicone breast implant was proposed as a substitute and turned down: not engineered for the forces of walking or running, and in any case it would feel like wearing one as an insole.

The Hybrid III could tell you a blast had reached the lower body. It couldn't say whether the injury was recoverable or permanent, and it couldn't answer what Brockhoff considered the actual question: at what magnitude does treatable become incapacitating?

WIAMan (Warrior Injury Assessment Manikin) is a hundred-person project: a blast-specific dummy calibrated from cadaver tests, with bone-mounted sensors feeding data through wires laid down the length of each limb. It exists because someone had to name the gap. Down at Aberdeen Proving Ground, the Army's primary test facility, two cadavers in orange and yellow Lycra are already on the tower, waiting for the charge.

The Military Doesn't Have a Noise Problem. It Has a Quiet Problem.

The earplug problem follows the same script. The standard solution to military hearing loss creates the same clinical problem it's meant to prevent. That's the diagnosis Eric Fallon, a former artilleryman turned military audiologist, arrived at after decades of watching foam earplugs fail soldiers. A standard earplug muffles sound by about 30 decibels: enough to bring a rifle crack down to something manageable, but also enough to reduce a soldier's hearing to the level where, if it were a permanent loss, he'd need a waiver to stay deployable. "What are we doing when we give them a pair of foam earplugs?" Fallon asks. "We're degrading their hearing to the point where, if this were a natural hearing loss, we'd be questioning whether they're still deployable. If that's not insanity, I don't know what is."

You might think the problem is compliance — soldiers who just don't bother to insert their plugs. But compliance isn't the problem. A patrol runs thirteen hours. Roughly 95 percent of it is silence: walking, waiting, scanning. IEDs don't send warnings. There's no formation call before a firefight, no moment to take off your helmet, pull back your ear, and properly seat a plug the way you can at a firing range. Wearing earplugs at a level that actually protects your hearing means spending most of that patrol effectively deaf to the commands, footsteps, and ambient sounds that keep you alive. Nobody does that. Fallon's summary of the actual problem: "The military doesn't have a noise problem. It has a quiet problem."

The measurable cost runs to roughly a billion dollars a year in VA payments for hearing loss and tinnitus. Researchers at Walter Reed found a more immediate one when they outfitted 101st Airborne soldiers with helmets rigged to simulate mild hearing loss. Even mild degradation made soldiers half as effective at identifying and engaging threats, not because they were navigating wrong, but because degraded hearing made them tentative. Sound is how soldiers know what's happening — more than half of battlefield awareness is auditory — and when that channel degrades, they hesitate. In combat, hesitation is the injury.

Walter Reed Will Rebuild a Urethra From Cheek Tissue but Won't Fund a Sex Therapist

The reconstruction work at Walter Reed is technically dazzling. Surgeons harvest a strip of tissue from the inside of a patient's cheek — hairless and tolerant of moisture — and use it to rebuild a urethra destroyed by a buried bomb. For men who've lost a penis entirely, the solution is more elaborate: forearm skin split into two layers, the inner rolled into a tube for a urethra, the outer wrapped around it for a shaft, the assembly left to develop its own blood supply before being detached and repositioned. The inflatable implants that replace erectile tissue cost about $10,000; Walter Reed covers them. The surgery exists, it works, and the institution funds it.

Then Christine DesLauriers spent seven years trying to get the Defense Department to put one sex therapist on staff.

DesLauriers runs the hospital's sexual health program. For seven years she took her case to military boards and received what she calls extensive support — almost entirely verbal. The stalling wasn't purely about money. At one point she sat across from the admiral who chaired the relevant board. He told her he didn't understand what anyone would be teaching a patient who no longer had a penis. What was there to help with?

She had options. Her colleagues had compiled an occupational therapy manual that addresses, without flinching, sexual positioning for triple amputees and vibrator modifications for patients who'd lost both arms. She went simpler: "Sir, if I can be very candid with you. Does he have a tongue, and can he be taught?"

One Marine told DesLauriers he'd had thirty-six operations on a surgically rebuilt shaft without any provider explaining how he was supposed to use it with his wife.

When the author asks about the divorce rate, DesLauriers corrects her: "How about suicide rate. And what a shame to lose them after they've made it back. We keep them alive, but we don't teach them how to live."

The Science Exists. Getting It to Soldiers Is the Second War.

Imagine a treatment that earned FDA approval, costs almost nothing per dose, works on wounds that antibiotics and surgery can't close, and has a patient refusal rate you could count on one hand. FDA approval, it turns out, just means the argument moves indoors.

Blowfly larvae received FDA clearance as a medical device in 2007. David Armstrong, a surgeon running a limb salvage clinic in Arizona, has applied them to over a thousand patients with almost no refusals. A 2012 survey of Army physicians found that 85 percent thought access to maggot therapy would be a valuable resource. Only 10 percent had ever prescribed it. The gap between those numbers isn't a knowledge failure. It's an institutional one.

The reasons had nothing to do with efficacy. They had to do with a colonel watching the setup and shaking his head: "And we're using maggots." With nursing staff who found the dressings revolting. With the logistical reality that each round of larvae has to be wiped out by hand before the next dose, and with a line in the product insert, matter-of-fact enough to be alarming, that escaped maggots become flies in an operating room. When George Peck at Walter Reed sought funding to study maggot therapy for IED wound infections, the preliminary results looked promising. The funding wasn't renewed. The institution preferred the familiar.

The research holds up. What doesn't is the distance between proven and practiced. The gap is filled with discomfort dressed up as process, and it carries a body count — slower and quieter than any wound, but real.

Yellow Plus Blood Equals Pink

The 7th Combat Mortality Conference, a standing Defense Department program called Feedback to the Field, brings eighty people together across three continents: doctors in Afghanistan, surgeons in San Antonio, medical examiners in a low tan brick building in Dover where, at peak Iraq-war tempo, twenty to thirty bodies arrived each week. They share audio and a screen of autopsy photographs. What the dead can teach, when examined carefully, will protect the next soldier.

The conference works through its cases with clinical precision: a tourniquet misplaced, placement instructions dispatched to everyone. The feedback loop closes. Someone will do it right next time.

The last case is a woman shot from behind. Her intraosseous lines (needles drilled into bone when veins collapse from blood loss) were placed correctly. There wasn't much else to be done. Defense Department policy leaves clothing on the body, and she arrived wearing pale yellow underwear, plain. The second slide shows her facedown. The fabric has turned pink. It takes a moment to understand why. Yellow plus blood equals pink. Mary Roach offers no comment.

Pete Seguin handles the printout photos every day. The bodies don't look real, he says — porcelain dolls, white from lividity, blood drained by gravity during transport. Then his voice drops. These are all young people, he says. Our kids. It makes you ask questions. Like, was it worth it? Photographers need a stepladder to fit the whole body in frame. It's the closest thing in the room to an answer. War, she decides, is like that. You'd need one impossibly tall to see far enough back to know.

The Stepladder Is Never High Enough

Every account of military conflict has a gap where these people should be. The ones who fired chickens into canopies, wired cadavers in orange Lycra, argued with admirals about whether a man still has a tongue. They don't appear in dispatches or citations or histories. They're in a lab somewhere, solving a problem nobody will think to credit them for. You'll notice that gap now.