The number of satellites, especially those operating in low-earth orbit (LEO), is exploding in recent years. Additionally, the use of COTS hardware into those satellites enables a new paradigm of computing: orbital edge computing (OEC). OEC entails more technically advanced steps compared to single-satellite computing. This feature allows for vast design spaces with multiple parameters, rendering several novel approaches feasible. The mobility of LEO satellites in the network and limited resources of communication, computation, and storage make it challenging to design an appropriate scheduling algorithm for specific tasks in comparison to traditional ground-based edge computing. This article comprehensively surveys the significant areas of focus in orbital edge computing, which include protocol optimization, mobility management, and resource allocation. This article provides the first comprehensive survey of OEC. Previous survey papers have only concentrated on ground-based edge computing or the integration of space and ground technologies. This article presents a review of recent research from 2000 to 2023 on orbital edge computing that covers network design, computation offloading, resource allocation, performance analysis, and optimization. Moreover, having discussed several related works, both technological challenges and future directions are highlighted in the field.

翻译：近些年来，卫星数量激增，尤其是运行在低地球轨道（LEO）的卫星。此外，将商用现货（COTS）硬件应用于这些卫星催生了一种新的计算范式：轨道边缘计算（OEC）。与单卫星计算相比，OEC涉及更为先进的技术步骤。这一特性带来了包含多参数的广阔设计空间，使得多种新颖方法成为可能。与传统的基于地面的边缘计算相比，LEO卫星在网络中的移动性以及通信、计算和存储资源的有限性，使得为特定任务设计合适的调度算法颇具挑战。本文全面综述了轨道边缘计算中的重点研究领域，包括协议优化、移动性管理和资源分配。本文提供了首个关于OEC的全面综述。以往的综述论文仅关注基于地面的边缘计算或天地技术融合。本文回顾了2000年至2023年间关于轨道边缘计算的最新研究，涵盖网络设计、计算卸载、资源分配、性能分析与优化。此外，在讨论若干相关工作的基础上，本文还重点指出了该领域的技术挑战与未来发展方向。