  A class of exact solutions of Einstein's equations is presented which
describes accelerating photon rockets in de Sitter and anti-de Sitter universe.
These are particular members of the Robinson-Trautman family of axially
symmetric spacetimes with pure radiation. In particular, generalizations of
(type D) Kinnersley's rockets and (type II) Bonnor's rockets to the case of a
non-vanishing cosmological constant are given. Some of the main physical
properties of these solutions are investigated, and their relation to the
C-metric solution which describes uniformly accelerated black holes is also
given.
