The Future of Advanced Air Mobility

Lockheed Martin Backs Megawatt-class Electric Propulsion Developer H3X

Lockheed Martin is backing technology start-up H3X in the development of an integrated modular motor drive that it says will deliver the quantum leap in power density and fault tolerance needed to power 50- to 100-seat aircraft. The value of the U.S. aerospace and defense giant’s investment in H3X was not disclosed in a February 28 announcement, but it takes H3X’s funding total to $9 million.

According to H3X, the new capital will allow it to accelerate the development and commercialization of its HPDM family of motor drives and scale up its Louisville, Colorado headquarters to be ready for production. The company, which was founded in 2020, is already in talks with aircraft manufacturers about possible applications for its 2.8-megawatt HPDM-3000 drive, which is expected to deliver a continuous power density of 12.5 kW/kg. It is also developing smaller drives designated as the HPDM-30 and the HPDM-250.

“At H3X, we are building integrated motor drives from 30 kilowatts to three megawatts that are unparalleled in performance in terms of specific power [kW/kg] and efficiency,” said co-founder and CEO Jason Sylvestre. “We are thrilled to have support from Lockheed Martin and are excited for the opportunity to work together on next-generation defense technology using our motors.”

According to H3X, its engineering team has achieved continuous specific power ratings of up to 10 kW/kg. It says this is based on advances in technologies including electromagnetics, material science, power electronics, additive manufacturing, motor controls, and thermal components.

The company intends its drives to be used for all-electric and hybrid-electric aircraft, either with new designs or to retrofit existing platforms. They can be used to drive propellers or high-bypass turbofans without a gearbox.

H3X says its electric motor drives will be lighter and more energy efficient.
H3X says its electric motor drives will be lighter and more energy efficient. (Image: H3X)

“When you look at the power density and efficiency requirements that are needed for electrifying narrowbody jets, there really isn’t anything out there that is sufficient,” Sylvestre said. “The megawatt-class systems that you can buy today still use technology from the last century and are far too large, heavy, and inefficient to meet the demanding requirements of electric aviation.”

Less Weight, More Power

By integrating all the elements of the propulsion system, including inverters, into a single housing, H3X says, it will reduce the mass of the hardware required, including expensive phase cabling and connectors. In theory, the modular HPDM-3000 could be stacked up to six times to deliver up to almost 17 megawatts of propulsion power for even larger aircraft.

Lockheed Martin indicated that it may use HPDM drives for multiple military applications requiring electric power. In addition to aircraft, potentially, the technology could be applied to marine, ground vehicle, and power generation use cases. The group has previously invested in eSTOL aircraft developer Electra and Elroy Air's Chaparral VTOL cargo drone.

“Our investment in H3X reinforces Lockheed Martin’s commitment to developing predictive capabilities and scaling solutions that allow the U.S. and its allies to stay ahead of threats,” commented Chris Moran, vice president and general manager of Lockheed Martin Ventures.

H3X aims to have a full-scale HPDM-3000 prototype ready to start testing in the third quarter of 2023. The company says additional test units should be available for customers and partners in 2024.