re: When, if ever will we have spacecraft that can travel at light speed?

You can't really reach light speed, it's against the laws of physics

Approaching light speed is actually a theory for traveling to the future. For instance, if you can never reach light speed according to the laws of physics, if you are on a vehicle travelling 99% the speed of light, the closer the vehicles gets to approaching light speed the slower the objects in the vehicle move so that they will never reach light speed. This means that everything outside the vehicle is moving in normal time while time within the vehicle is crawling

Light year travel may have to rely on a warp drive, warping space and literally riding a wave of time and space, the vehicle technically remains still while time and space move around it( Or we could figure out worm holes