TechReviewAl writes "Former astronaut Franklin Chang Diaz believes that the private sector can revitalize NASA, and his company is developing a plasma rocket to back up that claim. Chang Diaz argues that private industry can be used to develop much of the basic technology needed for space exploration, allowing NASA to focus on more sophisticated and critical components. His company, Ad Astra, is developing a variable specific impulse magnetoplasma rocket (VASIMR) that will be used to reposition the International Space Station. Last week, the rocket passed an important milestone in testing — reaching 200 kilowatts (enough to move the ISS). A video of the rocket can be seen on Ad Astra's site."