After several years of research, I have successfully developed a new concept that is not based on a mass expulsion type rocket engines. The working of this new concept is based on the principle that friction is non-conservative or friction is dependent on path (so reaction of friction force is also path dependent); whereas magnetic force is conservative or magnetic force is independent of path (reaction of magnetic force is path independent). The concept is described below. This new concept requires less propellant onboard; reduction of fuel carried and increasing thrust is of paramount importance to maximize Space flight efficiency. Fuel carried on board has a major role in reducing the range considering the fact that at take off 90% of weight of spacecraft is of fuel. Since in my concept no mass is expelled; the specific impulse could be infinity; (specific impulse is the ratio of the amount of thrust produced to the weight flow of the propellants). The ratio of propellant to payload rises exponentially as the ratio of DV to exhaust velocity increases.

Principle of concept: This non-mass expulsion type device uses properties of line integral and path dependent nature of friction force. The new device can achieve near light speed using properties inherent to relativity. In cases like LHC while particle moves at light speed the force is applied from stationary. But in new device force applied from and space craft is in same inertial frame, so comparatively less energy is required to attain light speed. For a Path independent force or conservative force work done in a closed path or its line integral must be zero; Vice versa for path dependent force like friction. if friction of ball in closed path can do some work then there is equal and opposite reaction of that work done on space craft resulting in motion of space craft according to third law of motion by newton.

Working of Concept: the working of there new concept is based on the principle that friction is non-conservative or friction is dependent on path; whereas magnetic force is conservative or magnetic force is independent of path. A conservative force is a force with the property that the work done in moving a body between two points is independent of the path taken. Equivalently, if a particle travels in a closed loop, the net work done (the sum of the force acting along the path multiplied by the distance travelled) by a conservative force is zero. However in case of non-conservative force like friction work done in moving a body is dependent on path taken. The gravitational force, spring force, magnetic force (according to some definitions,) and electric force (at least in a time-independent magnetic field, see Faraday's law of induction for details) are examples of conservative forces, while friction and air drag are classical examples of non-conservative forces.