12. What power sources can a VASIMR® engine use?
The radio-frequency (RF) power needed by a VASIMR® engine would typically be generated using solid-state generators very similar to those used in broadcast radio. These very efficient (up to 98%) RF generators would typically be powered by a direct current (DC) electrical power source, such as a photo-voltaic solar panel, or other relatively low-frequency power generation device. For power levels above approximately 1 MW, or for deep space exploration beyond Mars, nuclear power sources would likely become more desirable than solar because of the limited solar power density available as one moves beyond Earth's orbit around the sun. Additional information can be found in our NETS-2013 publication.