Alternative power sources boost small drone endurance.

• Author: Versprille, Allyson

* The U.S. military is looking for ways to improve the endurance of small unmanned aerial systems using alternative power sources, said service and industry officials.

When using small drones--which typically run on lithium-ion batteries --there are several shortfalls that need to be overcome in order to make the systems more effective for warfighters, said John Jennings, the director for innovation in the office of the assistant secretary of defense for operational energy plans and programs (OEPP).

"Typically what people want is greater range and endurance, basically being able to stay up longer and fly farther," he said. Additionally, "they want them to have greater onboard power. You're not flying them just to fly them, you're flying them because you have a pay-load and those payloads usually [need] power."

Reliability is also a factor because many of the smaller systems were not designed to run for long stretches of time, he noted.

OEPP is tasked with "maximizing the military capability we get out of energy while reducing the burdens and risks that our energy supply lines create," Jennings said. While the office doesn't solely focus on alternative power sources in order to achieve that goal, it is one of the tools the Defense Department uses to squeeze every drop of energy out of its systems, he said.

The operational energy capabilities improvement fund (OECIF) is one of the ways the department promotes technology that will improve operational energy performance. It contributes science and technology research funding to several military projects and encourages the services to take risks and move in new directions, Jennings said.

To decide which programs will receive that funding, OEPP asks the military to propose programs. From those submissions the office chooses which projects to fund, and the services themselves execute and manage them, Jennings explained. For fiscal year 2016, the Obama administration requested $37.42 million for the fund.

One program that currently receives seed funding through OECIF--though the Navy and Marine Corps are financing the majority of the project--looks at harvesting both solar and thermal energy to power a small unmanned aerial vehicle for an extended period of time.

"The Navy and the Marine Corps have gaps with regard to UAV capabilities," said Capt. Anthony Ripley, the science and technology lead for the Marine Corps' expeditionary energy office. "This effort will enable us to close a lot of those...