I need to know about the 3 conditions which are need necessarily to travel to the stars. My answer is below. Please add any other information, thanks. Not so sure if my answer makes sense.

3 conditions which are needed neccessarily to travel to the stars are a way to exceed the speed of light. A system to power a spacecraft without fuel and a way to take advantage of the energy in space.

2 answers

I don't know if the speed of light needs to be exceeded, although warp and wormholes, and distortion of space-time is very inviting. Transportation is a possibility.
The main thing I see as a condition to travel to other star systems is the lack of a clear economic or scientific benefit that has some present value.

see http://en.wikipedia.org/wiki/Interstellar_travel
thanks