Nearly 50 years after the first moon landing, NASA has set the goal to send the first human crew to Mars. A future spacecraft capable of such performance might have plasma engines, according to an article published by Space.com
A journey to Mars could take almost a year
The journey to the Moon lasted only three days, while a mission to Mars will take nearly a year. The differences between the two missions is not limited only to the time factor. To get to Mars and back, much more supplies will be needed. More, once they arrive on Mars the astronauts will have to build a base that will remain there for some time.
The transport of the supplies and equipment through space will require a new propulsion technology. Thus, the plasma engine reserved exclusively for spaceflight could be the solution.
Plasma engines -- a highly effective technology
Mars is at a distance of more than 100 times bigger than the one that's between the Earth and the Moon. The propulsion system used in the Saturn-Apollo missions can only carry the equivalent of a wagon of a train to the Moon. Unfortunately, for now there is no alternative to the rockets used for launching from Earth. But there is hope. Once the next shuttle reaches into space and heads to Mars, a new propulsion technology, more efficient in terms of fuel consumption, may be required: plasma engines.
The plasma engines work by converting the fuel into a very hot soup of particles with an electric charge (plasma) that is used to launch the spacecraft. Using plasma engines instead of traditional engines can reduce up to 90% of the fuel consumption while the ship is in space. Thus, a load with 10 times bigger mass will be transported to Mars at the same volume of fuel in the tanks.
NASA mission planners are already evaluating different ways of transportation with plasma engines to ensure the supply of a possible future human outpost on Mars.
Plasma engines are not very strong
The main problem of the plasma engines is that their strength is very low. The most powerful space engine with plasma that has already been used in missions is called Hall Thruster and it produces enough energy to carry into orbit..... just a piece of paper. Fortunately, the weak traction force of these engines is not an insurmountable problem, they will be used only after the probes or the spacecrafts already reach into space.