You might assume that missile assembly is quite the precision job given the extra incentive to limit mistakes on the factory floor. But for decades, missile assembly hasn't changed much and errors are not uncommon.
Technicians move large components around on rolling carts and then attaching those parts with hand-held tools. This has sometimes led to mismatched parts getting connected, raising the risks for factory workers as well as for the shipmen who later handled the weapons at sea.
"Missiles have always been a heavily manually-intensive operation," said Randy Stevenson, the director of Raytheon Missile Systems' Weapon Integration Center. "There's lots of materials handling [and] loading onto fixtures to assemble. There's lifting, and moving by hands, for the most part. It hasn't always been the safest operation."
But in 2009, as Raytheon's Camden, Ark., facility edged closer to maxing out its production capacity, the giant military contractor set out to build a new assembly operation in Huntsville, Ala., home to the US Army's Redstone Arsenal, NASA's Marshall Space Flight Center, and even Space Camp. It also gave the designers of the new plant an opportunity to take advantage of more efficient, high-technology already in use in other industries.
"If we were king for a day -- we were given a blank sheet of paper -- what would we do differently?" explained Stevenson. "What we've done here in Huntsville is the end result."
I had hoped to check out the Huntsville plant as part of my summer CNET Road Trip, but scheduling didn't work out. Instead, to get in the Road Trip frame of mind, I talked with plant executives by phone. It's not the same as a behind-the-scenes tour, but still a good chance to learn more about this high-tech missile factory.
The timing of the new plant is propitious. Even though the global missile production industry is dominated by Raytheon and Lockheed Martin, foreign rivals are nipping at their heels. According to recent press reports, the China North Industries Corp. may surpass the Americans in missile production sometime within the next five years.
Raytheon says that it has built nearly 2 million missiles since the early 1950s and remains the biggest manufacturer in the world. Clearly, the technology-heavy Huntsville facility, which cost $75 million to build, ought to help Raytheon deal with the stepped-up competition from China. And if past is prologue, the early results offer an encouraging harbinger: Raytheon recently scored contracts worth $350 million for the SM-3, and $243 million for the SM-6, the two missiles being made in the Alabama plant.
SM-3 and SM-6
Raytheon is reluctant to talk about how many of its missiles it makes. In a telephone interview, Huntsville plant manager Angel Crespo said the company can turn out between four and six SM-3s (for Standard Missile-3) and 10 to 12 SM-6s each month.
Raytheon describes the SM-3 as "a defensive weapon used by the U.S. Navy to destroy short- to intermediate-range ballistic missile threats." Last month, the US Navy completed a successful test of an SM-3 to show that the weapon could be fired from both sea and land. The SM-6, Raytheon says, provides the Navy "defense against fixed- and rotary-wing aircraft, unmanned aerial vehicles, and land-attack anti-ship cruise missiles in flight, both over sea and land."
All told, Raytheon makes 20 different missiles for clients around the world.
According to Stevenson, the Huntsville plant has been able to grow that production capacity -- which is larger than what Raytheon could turn out in Camden, Ark. -- thanks to efficiencies at the new high-tech facility. Fourteen technicians and about 36 support staff can produce more missiles than the staff of 80 to 100 that worked in Camden, he said.
Perhaps the most important element in that boost in capacity is the suite of automated tools that limit the amount of manual lifting of ordnance-laden components. "One of the things you want to do with explosive components is minimize material handling of them," Stevenson said. "We wanted to get [manual push carts] out of our factories."
The aha moment came when Raytheon representatives saw automatic guided vehicles, or AVGs -- essentially autonomous rolling carts -- in car manufacturing plants. In Huntsville, Raytheon has three of them, and may add more if production ramps up. But these are expensive, even by normal AVG standards. While the auto industry's AVGs run about $150,000 to $250,000, Stevenson said Raytheon's cost the company $700,000 apiece.
The extra cost is due to the vehicles being specially outfitted to move missile components around with no human intervention. They're Wi-Fi enabled and aware at all times of their location in the facility via an active laser system that constantly scans 360 degrees for light targets mounted on the walls. Thanks to a map of the factory loaded in the AVGs' memory, they drive themselves to precisely where their payload is needed.
When a new work order is begun, Crespo said, an AVG rolls automatically into the "kitting room" to pick up the "kit" -- the proper set of components for the job -- and then heads for the designated work station. This is big progress in the missile industry, Crespo suggested. Because that process is automated, there are no cases where an employee accidentally sends the kit to the wrong technician, an occasional problem in Raytheon's 10 other factories in three locations around the US.
Manufacturing Innovation and Intelligence
Another newcomer to Raytheon's missile production regimen is a graphical software interface deployed on the Huntsville factory floor. Known as the Manufacturing Innovation and Intelligence (MMI) system, it is meant to guide operators and technicians through their workdays -- making certain the steps they're taking and the components they're working with are exactly what's intended. Because the assembly process is highly regimented, with every component and fastener having a specific place to go, it's essential that things be done the right way.
In the past, Crespo explained, though each step was documented as it was performed, mistakes were sometimes made thanks to typing errors, or mistakes in documenting a step. A very big part of the job of making a missile is connecting thousands of individual fasteners, each of which calls for the application of a prescribed amount of torque. Now, every single component and fastener has a bar code that must be scanned, and the MMI makes sure that workers are unable to proceed if they have the wrong parts. "A serial number gets automatically entered into the system," Crespo said. "No keystrokes, so no chance for wrong keystrokes to be entered."
At the same time, Raytheon is now using automatic torque controllers that feed information to automated screwdrivers about how much torque an individual fastener requires. "If for some reason, an operator...didn't [use] the screwdriver properly," Crespo said, he or she gets "an alert saying you did not torque that one right. You have to do it" again.
If they try to ignore the alert, the MMI system won't let them move on to the next step.
Ultimately, the MMI system is meant to record every step that goes into the assembly of a missile, generating an archived "pedigree" available to both Raytheon and military auditors. The system tracks who worked on a missile, when they did it, and which tools they used. "If it needed 148 fasteners," Stevenson said, "it can tell you every fastener installed, and the torque factors."
Before a missile is a missile, all of its components need to be put together in just the right way. After all those pieces -- guidance systems, propulsion, fins, control surfaces, and others are fit together -- technicians take them to a safe, controlled area for testing. This is the only time that the weapons get operated while still in Raytheon's hands. Assuming that all its systems function properly, the missile then gets returned to the factory floor for one final step: putting it inside its cannister.
According to Stevenson, the cannister is considered as much a part of the weapon system as the rest of the missile. Meant to be physically connected to the Navy's ship, they're provided to Raytheon by the Navy. The job at this point is to assure the missile is "mission ready" and then seal it inside the cannister. The moment that's done, the weapon is complete. Known formally as an All-Up Round, or AUR, this is Raytheon's final product.
But missiles often spend years outside the factory without being fired, and many of their components have a shelf life. That means that after 3-to-5 years, the factory will get back some of the AURs, which will be disassembled, their parts taken out and tested again, or replaced in the case of some time-sensitive components, and then re-assembled.
Thanks to the implementation of all the factory's technology, this process has been improved as much as original assembly. It might seem odd that missiles are returned and taken apart, but that's the game. "At any given time," Stevenson said, "you would see product going in both directions."
Keep an eye out for more behind-the-scenes stories and photo galleries as I travel throughout Oklahoma, Arkansas, Tennessee, and Kansas during this year's Road Trip. I'll seek out most interesting technology, military, aviation, architecture, and other destinations our country has to offer. From US Air Force basic training to NASA's Johnson Space Center and FedEx's massive package-sorting hub, Road Trip 2014 will take you along with me.