https://gizmodo.com/nasa-pulsed-plasma-rocket-advanced-concept-mars-1851463831 [gizmodo.com]
"The future of space travel depends on our ability to reach celestial pit stops faster and more efficiently. As such, NASA is working with a technology development company on a new propulsion system that could drop off humans on Mars in a relatively speedy two months' time rather than the current nine month journey required to reach the Red Planet...
The potentially groundbreaking propulsion system is being developed by Arizona-based Howe Industries. To reach high velocities within a shorter period of time, the pulsed plasma rocket would use nuclear fission—the release of energy from atoms splitting apart—to generate packets of plasma for thrust.
It would essentially produce a controlled jet of plasma to help propel the rocket through space. Using the new propulsion system, and in terms of thrust, the rocket could potentially generate up to 22,481 pounds of force (100,000 Newtons) with a specific impulse (Isp) of 5,000 seconds, for remarkably high fuel efficiency"...
"The space agency claims that the propulsion system's high efficiency could allow for crewed missions to Mars to be completed within two months. As it stands today with commonly used propulsion systems, a trip to Mars takes around nine months."...