City Journal: Heavy Mettle

Burlington-based iRobot is famous for its vacuuming Roombas, but it’s the company’s bomb-busting bots that do the real dirty work. The newest (and toughest) version is just now hitting the streets of Iraq.

1. Bombs Away

The PackBot grew out of an assignment from the U.S. Defense Department, which needed a bomb-stopping robot that was portable yet rugged enough to survive in a war zone. Since the first ones shipped in 2002, more than 800 have been searching caves, spotting mines, and thwarting roadside explosives in Iraq and Afghanistan. The bomb busters have become movie stars, too, appearing in Inside Man and Mr. & Mrs. Smith.

2. Well Armed

The PackBot functions by scooting close to a suspected bomb and detonating it with a tiny blast. Despite the robot’s small size—it weighs just 68 pounds—its arm can stretch more than 6 feet, allowing one of its three video cameras to peer over walls or into cars. Its claw “hand” can hoist 30-pound objects, and its motors can get it rolling at nearly 6 miles per hour. All of that for between $60,000 and $120,000.

3. War Games

A second-generation device called the PackBot 510 has just been deployed to Iraq. It’s operated with a PlayStation-style controller, making training a cinch for today’s game-savvy soldiers—“It’s already done,” says iRobot cofounder Helen Greiner. When engineers had to test the controller, they called in experts: the kids of employees.

4. That’s a good boy!

A new bomb-sniffing attachment called the ICx Fido—built with technology invented by the head of the MIT chemistry department—can detect trace chemicals in hidden bombs. Another add-on, the RedOwl, is being developed with assistance from the BU Photonics Center, and uses sound sensors, thermal imaging, and lasers to spot enemy snipers.

5. Screwdriver, STAT!

PackBots are built to withstand forces equivalent to falling 10 feet onto concrete, but they still get plenty banged up. For repairs, they go to “robot hospital.” Recently, a Marine unit was crestfallen to learn that technicians couldn’t fix its PackBot, nicknamed Scooby-Doo, which the soldiers had given a notch for each of its 18 successful missions. “A colonel told me, ‘You know, when a robot dies you don’t have to send a letter to its mother,’” Greiner says.

6. Cash Machines

With $1.7 billion expected to be spent on military robots over the next five years, the PackBot’s competition will be fierce. And close by: Waltham-based Foster-Miller is cranking out its own bomb detector and even experimenting with unit-mounted machine guns—innovations that will no doubt push iRobot to dream up more improvements for the PackBot.

The robot’s “head” can be outfitted with bomb-detecting hazmat sensors or a color video camera that can operate in low light and boasts 312x zoom.

The PackBot’s swiveling clamp of a “hand” grabs and carries objects, and places the explosive charge used to neutralize a bomb.

Rotatable “flippers,” attached to the front of the tanklike tracks, allow the unit to climb stairs. A center-mounted camera shows operators where it’s headed.