A compact single shaft, low cost, long life, maintenance-free turboalternator scalable from 1 to 10s of kWe for human exploration of the moon and Mars is proposed. Operating at high spin speeds and based on a closed Brayton cycle using a binary He-Xe working fluid, the device combines five key enabling technologies to achieve high cycle and electrical efficiencies. MiTi’s innovation is the seamless integration of 1) MiTi's Sixth Generation low power loss; high load, damping and temperature foil bearings with high reliability and long life; 2) a compact single-shaft configuration that isolates the alternator elements from high temperature gases via a novel thermal barrier coated heat shield for improved thermal management; 3) a high efficiency direct drive permanent magnet high-speed alternator; 4) high adiabatic efficiency aero components; and 5) high effectiveness/low pressure drop recuperator. The specific design has its heritage in an open Brayton cycle turboalternator with a demonstrated specific power 1.6 kW/kg.
The proposed technology will satisfy NASA's need for power conversion from fission to support space exploration applications. This technology development will be suitable for stationary and transportation space power generation systems and will lay the groundwork for subsequent scaling to lower and higher power platforms (i.e., from 1 to 10 kWe or higher), capable of powering spacecraft on-board power, communication, navigation controls and electronics, life support systems, planetary rovers and machinery, and even planetary human settlements
Potential military and commercial customers would benefit from use of the proposed technology for microgrid and waste heat applications, including residential and industrial distributed waste heat recovery cogeneration applications. The U.S. military will benefit from the technology in areas of portable power for dismounted soldier and forward operating bases and power for all electric UAVs.