What technologies and theories do human beings need to achieve if they want to emigrate to another planet?

1. new energy, at least effective use of nuclear fusion. Even if you don't colonize Mars by nuclear fusion, it's hard ... only it can provide so much kinetic energy. To have zero energy, antimatter is better. ...

2. Propulsion mode, I believe that in the variable specific impulse plasma rocket, at least it will not be too slow. Sunshine sail, laser propulsion is simply snail speed. As for the working medium, Bussard can capture hydrogen atoms by magnetic force, which is similar to stamping gain propulsion. Curvature wormholes are temporarily forgotten, and it is difficult to make a breakthrough at present.

3. Lifestyle. Methods like hibernation will only reduce energy consumption. As you said, the injection is still a burden for the spacecraft. In science fiction, liquid helium is frozen and has no biochemical reaction, but it is difficult to freeze in the body and not die ... artificial gravity plus artificial ecology is still quite realistic, but it is too big. I hope the rockets will be violent enough in the future. Some people say that artificial gravity is not needed, and it will adapt before the planet.

4. Others, seriously, to achieve the above three points, the detection ability should be very strong, and it is no problem to get some deep space detectors. At present, the planets are all rough guesses, and it is not very reliable to look at the astronomical mirror during the transit. As for gravity difference, it's nothing.