  Space information networks (SIN) are facing an ever-increasing thirst for
high-speed and high-capacity seamless data transmission due to the integration
of ground, air, and space communications. However, this imposes a new paradigm
on the architecture design of the integrated SIN. Recently, reconfigurable
intelligent surfaces (RISs) and mobile edge computing (MEC) are the most
promising techniques, conceived to improve communication and computation
capability by reconfiguring the wireless propagation environment and
offloading. Hence, converging RISs and MEC in SIN is becoming an effort to reap
the double benefits of computation and communication. In this article, we
propose an RIS-assisted collaborative MEC architecture for SIN and discuss its
implementation. Then we present its potential benefits, major challenges, and
feasible applications. Subsequently, we study different cases to evaluate the
system data rate and latency. Finally, we conclude with a list of open issues
in this research area.
