NASA is to investigate a VASIMR propelled lunar tug concept according to a procurement synopsis it published last week. The video above can be found here along with other videos about the tug concept. The NASA synopsis says:
Studies will be conducted to evaluate a Lunar Tug concept utilizing Variable Specific Impulse Magneto-plasma Rocket (VASIMR) engine capabilities from Low Earth Orbit to Lunar Orbit and libration points.
The VASIMR was conceived by former NASA astronaut Franklin Chang Díaz and developed through his Ad Astra Rocket company. Chang Diaz's company and Houston, Texas based-MEI Technologies released a press release last week qouting MEI's chief executive Ed Muñiz saying:
"Ad Astra's impressive technology coupled with our payload integration capabilities will ultimately result in innovative cargo and supply mechanisms, greater access to resources and broader support for robotic and human missions in space," [emphasis added]
The text above, italicised by this blog, indicated something interesting was going on. Hyperbola is still waiting for a response to its request for an interview. New propulsion technologies have been mentioned by NASA administrator Charles Bolden as a focus for the space agency