In space, the physics that we have learnt in class usually applies without exception. On planets such as Earth and Mars, there are inefficiencies such as air resistance and friction that gives errors in the calculations that are performed to determine acceleration through force or velocity through acceleration. In space, there are almost no other particles to slow down the object you are trying to accelerate, so it will be very close to the theoretical movement.
There are many interesting ways that the laws of physics can be exploited to make space travel more easier, comfortable or economical. An example is to use a rotating circular chamber in order to simulate a gravitational force. Another example is to use stages to get rid of dead mass so that the efficiency of the fuel is increased. These examples will be further discussed in their respective sections.
Journey To Mars 