US space agency NASA as well as various other organizations are working on new technologies that would help mankind to reach Mars in less amount of time. Rocket Engine made out of plasma is one of many options proposed for the exploration of Mars and beyond mars.
Ad Astra company which is a startup was founded by physicist and former astronaut Franklin Chang Diaz is designing a plasma rocket engine called VASIMR, this rocket will allow large crew members to reach Mars three times faster than a normal rocket.
Difference between a normal rocket and plasma rocket is that normal rocket burns gases like hydrogen and oxygen that then creates a thrust when it leaves the nozzle.
Plasma rocket does not burn fuel, it uses the high intensity electromagnetic fields to heat up gas to temperature millions of degrees hotter than ordinary combustion to generate the plasma. Plasma powered rocket can deliver 60 tons of cargo to Mars in 90 days.