I read that what they do is "hitch" a ride in front of a star.
I don't quite understand because apart from the Sun, the next nearest start is Alpha Centauri which is still 4.5 light years away which is still a
long way away.
An 'antigravity' propulsion system was proposed at the Space Technology and Applications International Forum (STAIF) in Albuquerque on Febuary 14 by Dr. Franklin Felber. His new exact solution to Einstein's gravitational field equation gives hope to space enthusiasts that it might be possible to accelerate space craft to speeds approaching that of light without crushing the contents of the craft. If it works, it could be even better than apergy, as described by science fiction writer Percy Greg in 1880