Summer 2004 Vol. 4 No. 2
Powering Up the High-Tech
Taking advantage of today's advances in communications and computer technologies, the U.S. Army has started outfitting its troops with the latest devices to give soldiers a real-time picture of the battlefield and enhance their tactical effectiveness. But these capabilities come at a cost. Besides adding to the dismounted soldier's current physical load -- sometimes in excess of 100 pounds -- the new equipment will need to be powered long enough for soldiers to accomplish their missions independently without being resupplied.
Through a program called "Land Warrior," the Army is acquiring high-tech gear that will greatly increase the soldiers' awareness of the combat environment, such as helmets with visual sensors, chemical and biological sensors, digital radios, and hand-held computer displays. A new report from the National Research Council examines various portable energy sources and technologies that could ensure enough power for well-equipped missions lasting up to three days, and for other future soldier applications that would require higher levels of energy. These power sources will be key in enabling what the Army calls the Future Force Warrior, successor to the Land Warrior program.
"Ensuring adequate power for dismounted soldiers is by no means a simple problem," said Patrick Flynn, chair of the committee that wrote the report and retired vice president for research at Cummins Engine Company Inc. "The Army needs to consider not only energy sources, but also different types of equipment and efficient management tools and techniques. But here's the good news: Solutions are currently available on the market, and no major breakthroughs will be necessary to develop these energy sources."
The computers, sensors, and communication devices that will equip soldiers' future gear have different energy requirements, so the committee examined a variety of technologies that would meet the Army's needs. For example, standard military batteries can provide enough power for computer displays, radios, sensors, and electronics for a 12-hour mission, but for missions lasting up to 72 hours, other technologies -- such as rechargeable batteries, sophisticated software to manage power, and hybrid energy systems -- will be needed, the report notes.
Some of the applications requiring higher power -- an average of 100 watts -- are portable battery rechargers, laser devices used to guide a rocket, missile, or bomb to its target, and individual cooling systems for protective garments. The cooling gear, which provides ventilation near the skin to allow sweat to evaporate, would be a blessing to soldiers deployed in hot regions but it is particularly power-intensive. For such applications, the committee concluded that fuel cells would perform better than rechargeable batteries.
Performance-enhancing devices, such as the "exoskeleton," which literally takes the load off of one's back to support large or heavy packs without reducing agility, use even more power and require 1 to 5 kilowatts. To power such energy-intensive equipment, the Army should consider use of fuel cells and small engine generators, the report says.
Among all possible energy sources, hybrid systems provide the most versatile solutions for meeting the diverse needs of the Future Force Warrior, the committee said. The key advantage of hybrid systems is their ability to provide power over varying extremes of usage by combining advantages of two power sources -- such as a battery and a fuel cell or an engine and a battery.
"Products historically have evolved to become more portable, mobile, and wearable," Flynn said. "By integrating components and minimizing the energy they consume, tomorrow's military equipment will help soldiers operate in various conditions, extend the range and duration of their operations, and minimize their vulnerability."
-- Patrice Pages
Meeting the Energy Needs of Future Warriors. Committee on Soldier Power/Energy Sources, Board on Army Science and Technology, Division on Engineering and Physical Sciences (2004, 136 pp.; ISBN 0-309-092620; available from the National Academies Press, tel. 1-800-624-6242; $23.00 plus $4.50 shipping for single copies).
Patrick Flynn, retired vice president for research at Cummins Engine Company Inc., Columbus, Ind., chaired the committee. The study was funded by the U.S. Department of Defense.