The ASCEND program supports the development of novel lightweight and ultra-efficient electric motors, drives , and associated thermal management system that will facilitate net-zero carbon emissions in the single-aisle, 150-200 passenger commercial aircraft segment. This FOA represents part of a wider ARPA-E effort in the development of enabling technologies for long-range (≥ 2,800 nautical miles), carbon neutral commercial aviation. The overarching goal is to reduce the emissions from commercial aviation by developing cost-competitive systems for the efficient conversion of the chemical energy of carbon-neutral liquid fuels (CNLFs) to delivered electric energy, which is then further converted to thrust via propulsors driven by electric motors and associated motor drives.