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May 7, 2003 — The war in Iraq caught the U.S. military in the very early stages of the small tech revolution. Only a few kinds of MEMS systems were used inside the weapons that overthrew the regime of Saddam Hussein. But it’s likely they will play a bigger role in any future war as dozens of pieces of MEMS-based military hardware move into advanced stages of development or procurement.
For the most part, MEMS technology was used in guidance, navigation and targeting systems. Some Humvees and Bradley fighting vehicles came equipped with a MEMS-based attitude sensor in their laser sights. The sensor, made by Crossbow Technology Inc., a privately held San Jose, Calif., company, determined the pitch and tilt of the sight so its computer could make corrections before transmitting targeting data.
In the skies over Iraq, the Global Hawk high-altitude Unmanned Aerial Vehicle, which uses a MEMS accelerometer, was flown over battlefields to give commanders large-scale, detailed and near-real-time views of what was happening on the ground. The high-flying Global Hawk came in especially handy over the fierce sandstorms during the early days of the war.
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Another system helped fighters adapt to the dusty weather. A MEMS-based system from Crossbow helped pilots land on carriers. “We got feedback that was real helpful in a blinding dust storm,” said John Crawford, Crossbow’s vice president of sales and business development.
There likely were other MEMS systems called into active duty in Iraq. The problem is getting anyone to admit it.
“Yes we have products used in the war effort,” said a representative of one MEMS manufacturer. Whether I can talk about them is another question.” Or as military contractor Honeywell International Inc. put it in a canned statement: “Contractual commitments with our defense customers do not permit us to publicly discuss the specifics of our work or operations.”
This reticence is partly because the U.S. Defense Department discouraged talk about weapons systems used in Iraq and partly because MEMS companies are typically subcontractors and don’t want to say anything without clearing it with their customers.
It is clear that MEMS technology will continue to creep its way into U.S. weapons systems. For example, the Army’s Excalibur guided 155 mm artillery round is scheduled to begin low-rate production in 2005. The Navy’s Extended Range Guided Munition artillery round is slated to follow in a year or two. And the Army’s XM395 precision-guided 120 mm mortar round will start production in 2005.
All of these systems use MEMS-based Inertial Measurement Units (IMUs) — three gyroscopes and three accelerometers linked together to form the guts of an inertial guidance system. Combined with a Global Positioning System (GPS) receiver, the IMU provides accurate, weatherproof, jam-resistant guidance to everything from artillery shells to bombs and missiles to torpedoes.
Navigation and sensors are other major areas for military MEMS that will grow rapidly over the next couple of years. In navigation, the military is looking to put a system in nearly every vehicle to pinpoint its location and direction of travel. Since a GPS can’t determine which direction a vehicle is pointing when it is standing still, this almost certainly means MEMS components.
There are a lot of MEMS sensor programs going on as well. For example, Crossbow’s Crawford also said that the company has demonstrated MEMS components in a system designed to monitor an area for people or vehicles without having to put a guard on it. The Army already has such a system in the Improved Remote Battlefield Sensor System (IREMBASS), but it is looking to for something smaller, lighter and, of course, cheaper. L-3 Communications Inc. is developing the REMBASS II system.
MEMS for the military doesn’t mean all new, or even mostly new, weapons systems. When it comes to MEMS, the buzzword at the Department of Defense is “insertion” — replacing older generation components with smaller, cheaper MEMS devices. One of the current Defense Advanced Research Agency (DARPA) research projects is aimed at producing a standard, low-cost (about $1,500) MEMS-based IMU.
DARPA wants something that will fit in everything from bombs to missiles to land navigation systems. One example of a candidate for a MEMS upgrade is the Air Force’s Wind Corrected Munitions Dispenser for scattering bomblets or mines over a selected area. The device uses an inertial guidance system to put it on target and the Air Force wants to replace the current ring laser gyro system with a MEMS-based one.
The Institute for Defense Analyses’ Web site lists literally hundreds of MEMS insertion opportunities with the U.S. military. They range from upgrades to existing weapons such as the Join Direct Attack Munition guided bomb, to advanced sensor systems for intrusion detection, to safety devices for fuses, to directed energy weapons.
Tomorrow: Companies combat unseen bio/chem enemies
Friday: Military eager to end ‘false positives’ plague