It would take a six to nine months to get to Mars with today’s chemical-fueled rockets. Along the way, according to a 2013 study, you’d get dosed with the radiation equivalent of a whole-body CT scan every five to six days, increasing your lifetime cancer risk above the limits set by NASA.
Upon reaching the Red Planet, you’d wait up to two years for Earth and Mars to be at their closest before your return trip, which would last another six to nine months. If the cosmic rays didn’t get you, the long layover might.
Franklin Chang Díaz, an MIT-trained physicist and former NASA astronaut, has spent more than 30 years tinkering with the rocket engine he invented, which he believes can transform interplanetary flight. In 2005, he founded a company, Ad Astra (Latin for “to the stars”), to pursue that same goal.
Ad Astra’s main project is the Variable Specific Impulse Magnetoplasma Rocket (VASIMR), an electro-magnetic thruster for spacecraft propulsion. It uses radio waves to ionize and heat a propellant, and magnetic fields to accelerate the resulting plasma to generate thrust. It is one of several types of spacecraft electric propulsion systems.
The method of heating plasma used in VASIMR was originally developed as a result of research into nuclear fusion. VASIMR is intended to bridge the gap between high-thrust, low-specific impulse propulsion systems and low-thrust, high–specific impulse systems. VASIMR is capable of functioning in either mode.
As of June 2013, Ad Astra completed a formal Preliminary Design Review (PDR) on the VF-200 engine, as a critical milestone on the development pathway to testing the VF-200 on a multi-month test on the International Space Station. A number of long-duration engine firings are planned, but no release date is schedule.