  The rise of NewSpace provides a platform for small and medium businesses to
commercially launch and operate satellites in space. In contrast to traditional
satellites, NewSpace provides the opportunity for delivering computing
platforms in space. However, computational resources within space are usually
expensive and satellites may not be able to compute all computational tasks
locally. Computation Offloading (CO), a popular practice in Edge/Fog computing,
could prove effective in saving energy and time in this resource-limited space
ecosystem. However, CO alters the threat and risk profile of the system. In
this paper, we analyse security issues in space systems and propose a
security-aware algorithm for CO. Our method is based on the reinforcement
learning technique, Deep Deterministic Policy Gradient (DDPG). We show, using
Monte-Carlo simulations, that our algorithm is effective under a variety of
environment and network conditions and provide novel insights into the
challenge of optimised location of computation.
