Before the invention of planetary shields, hyperdrive
equipped nuclear missiles were the standard weapon of
interstellar combat. Before the invention of astromech droids,
many of these missiles were manned, with the crew suffering the
gradual effects of radiation posioning before their fiery deaths.
While manned missiles are no longer used, droid manned warheads
are still an important facet of interstellar war, being used
against targets too poor to afford planetary shields, in
conjunction with specops strikes at shield generators, or against
lightly defended worlds.
The XRJ-87 is near the low end of cruise missile technology,
most commonly used in terrorist attacks, or as part of a larger
strategic structure. As the missile's hyperspace distortion
profile is not that much different than most light frieghters,
the slow hyperdrive just delays the strike, but makes it no
easier to prevent, and the two jump capacity of the droid brain
prevents direct tracing of the missiles vector back to it's
source. Once the missile comes out of hyperspace, it's heavy ion
engines will push it toward it's target at high velocity,
allowing it to outrun most pursuing craft if it survives the
initial barrage. Many missiles are set to detonate if heavily
damaged, so as to take out the ship that killed it, but as
detonation is a rather complex process, it often fails due to
that damage.