This paper provides a comprehensive survey of free space optical (FSO) communication, focusing on the challenges and mitigation techniques for ground-to-satellite, satellite-to-ground, and inter-satellite links. FSO communication, which uses optical carriers in the near-infrared (IR) band, offers advantages such as large bandwidth, license-free spectrum, high data rates, and low power and mass requirements. However, atmospheric effects like absorption, scattering, and turbulence pose significant challenges to its performance. The paper discusses various impairments that affect FSO systems, including atmospheric turbulence, beam divergence, and background noise. It also reviews performance mitigation techniques at both the physical layer and higher layers, such as adaptive optics, advanced modulation and coding techniques, and hybrid RF/FSO systems. Additionally, the paper highlights a recent technique using orbital angular momentum (OAM) to enhance data returns from deep space or near-Earth optical communication in turbulent atmospheres. The survey concludes with an overview of FSO technology's future scope and potential applications in space-based optical backhaul links.This paper provides a comprehensive survey of free space optical (FSO) communication, focusing on the challenges and mitigation techniques for ground-to-satellite, satellite-to-ground, and inter-satellite links. FSO communication, which uses optical carriers in the near-infrared (IR) band, offers advantages such as large bandwidth, license-free spectrum, high data rates, and low power and mass requirements. However, atmospheric effects like absorption, scattering, and turbulence pose significant challenges to its performance. The paper discusses various impairments that affect FSO systems, including atmospheric turbulence, beam divergence, and background noise. It also reviews performance mitigation techniques at both the physical layer and higher layers, such as adaptive optics, advanced modulation and coding techniques, and hybrid RF/FSO systems. Additionally, the paper highlights a recent technique using orbital angular momentum (OAM) to enhance data returns from deep space or near-Earth optical communication in turbulent atmospheres. The survey concludes with an overview of FSO technology's future scope and potential applications in space-based optical backhaul links.