Manufactures solid rocket propellant using proprietary 3D-printing technology for rocket motors and hybrid rocket engines, supplying US Air Force and other defense and aerospace customers.

Mantle Energy is a Dallas, Texas-based transitional energy company, founded in 2026 as a subsidiary of Hunt Energy, that repurposes depleted oil and gas wells for geothermal energy production by combining Enhanced Oil Recovery and geothermal technologies. The company raised $5 million in seed funding to commercialize its approach to geothermal energy using existing oil and gas reservoirs.