The "twin paradox" of special relativity offers the possibility to make
interstellar flights within a lifetime. For very long journeys with velocities
close to the speed of light, however, we have to take into account the
expansion of the universe. Inspired by the work of Rindler on hyperbolic motion
in curved spacetime, we study the worldline of a uniformly accelerated observer
in de Sitter spacetime and the communication between the traveling observer and
an observer at rest.Comment: 15 pages, 19 figures, 5 table