With the development of mobile edge computing (MEC), many approaches are proposed to improve the computation performances, such as network congestion, transmission latency, and quality of Internet of Things (IoTs) services. Although ground MEC system architectures are developed, there are still unsolved problems, such as depending on the ground infrastructure. Therefore, unmanned aerial vehicle (UAV) assisted MEC is considered to address these problems. However, the computation performance is limited by the UAV hover model, which is affected by the UAV’s velocity, acceleration, and a variable altitude. Nowadays, a terrestrial-satellite network (STN) plays a role in important 5G network development. The characteristics of an STN integrated with 5G are a low delay, high bandwidth, and ubiquitous coverage. Hence, 5G high-speed satellite-terrestrial assisted mobile edge computing (SMEC) is considered as a flying mobile edge computing, which will be discussed in terms of reasons, advantages, and open issues in this paper.