Direct Energy Conversion for Nuclear Propulsion at Low Specific Mass Project

<p>Low specific mass (&lt; 3&nbsp; kg/kW) in-space electric power and propulsion can drastically alter the paradigm for exploration of the Solar System, changing human Mars exploration from a 3-year epic event to an annual expedition.&nbsp;&nbsp; A specific mass of ~1 kg/kW can enable 1-year round-trips to Mars, regardless of alignment, with the same launch mass to low Earth orbit (350 mT) estimated by the Mars Design Reference Architecture 5.0 study for a 3-year conjunction mission. Key to achieving such a propulsion capability is the ability to convert, at high efficiency and with only minimal losses rejected as heat via radiators, the energy of charged particle reaction products originating from an advanced fission or aneutronic fusion source directly into electricity conditioned as required to power an electric thruster.&nbsp; The TWDEC concept accomplishes this by converting particle beam energy into radio frequency (RF) alternating current electrical power, such as can be used to heat the propellant in a plasma thruster.</p><p>This project is core to the development of multi-MW power for electric propulsion.&nbsp; The technology developed will enable high power systems which have specific mass in the low single-digits and which are sun-independent, require no neutron shielding, and produce no radioactive waste.&nbsp; The power levels and specific mass this technology could provide will, when combined with either high-efficiency Q-thrusters or VASIMR-class plasma thrusters, enable rapid human missions to Mars and beyond.&nbsp;&nbsp;&nbsp;&nbsp; Project Infusion Path: Low specific mass (a &ndash; kg/kWe) in-space electric power and propulsion can drastically alter the paradigm for exploration of the Solar System, changing human Mars exploration from a 3-year epic event to an annual expedition.&nbsp;&nbsp; An a of ~1 kg/kWe can enable 1-year round-trips to Mars, regardless of opportunity, with the same launch mass to low Earth orbit (350 mT) estimated by the Mars Design Reference Architecture 5.0 study for a 3-year conjunction mission. Key to achieving such a propulsion capability is the ability to convert, at high efficiency and with only minimal losses rejected as heat via radiators, the energy of charged particle reaction products originating from an aneutronic fusion source directly into electricity conditioned as required to power an electric thruster. The TWDEC concept (originally conceived in Japan in the 1990&rsquo;s for terrestrial fusion applications) accomplishes this by converting particle beam energy into radio frequency (RF) alternating current electrical power, such as can be used to heat the propellant in a VASIMR-class plasma thruster. In a more advanced concept (explored in a 2012 Phase 1 NASA Innovative Advanced Concepts (NIAC) project), the TWDEC could also be utilized to condition the particle beam such that it may transfer directed kinetic energy to a target propellant plasma for the purpose of increasing thrust and optimizing the specific impulse.&nbsp; While other government agencies and/or industry partners are pursuing aneutronic fusion reactors and plasma propulsion, NASA JSC is the only entity advancing this core energy conversion technology. With successful development of this system by NASA and its partners, an intermediate NASA infusion step would demonstrate megawatt-class aneutronic fusion, TWDEC, and electric propulsion (e.g., Q-thruster, VASIMR) systems on robotic missions to the Jovian moons.&nbsp; Human vehicle system development would then integrate such systems into the &ldquo;ultimate&rdquo; NASA application:&nbsp; sustainable, routine human exploration of Mars and, with successful Q-thruster development, beyond.</p><p><strong><u>Project Infusion Path:</u></strong></p><p>Low specific mass (a &ndash; kg/kW_e) in-spac