An optical downlink for the return of scientific data from space probes at interstellar distances is studied. The context is probes moving at relativistic speed using a terrestrial directed-energy beam for propulsion, necessitating very low mass probes. Achieving simultaneous communication from a swarm of probes launched at regular intervals to a target at the distance of Proxima Centauri is addressed. The analysis focuses on fundamental physical and statistical communication limitations on downlink performance rather than a concrete implementation. Transmission time/distance and probe mass are chosen to achieve the best data latency versus volume trade-off. Challenges in targeting multiple probe trajectories with a single receiver are addressed, including multiplexing, parallax, and target-star proper motion. Constraints on transmit aperture size make a compelling argument in favor of free-space optical communications, and this is the assumed approach for our baseline analysis....

中文翻译：

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低质量星际探测器对科学数据通信的挑战

研究了用于在星际距离从太空探测器返回科学数据的光下行链路。背景技术是使用地面定向能量束进行推进以相对论速度移动的探测器，因此需要非常低质量的探测器。解决了从定期发射的大量探针到半人马座近距离目标的同时通讯。分析重点在于对下行链路性能的基本物理和统计通信限制，而不是具体的实现。选择传输时间/距离和探头质量以实现最佳的数据等待时间与体积的权衡。解决了使用单个接收器瞄准多个探头轨迹的挑战，包括多路复用，视差和目标星体正确运动。