We present a ground-to-space quantum key distribution (QKD) mission concept and the accompanying feasibility study for the development of the associated low earth orbit nanosatellite payload. The quantum information is carried by single photons with the binary codes represented by polarization states of the photons. Distribution of entangled photons between the ground and the satellite can be used to certify the quantum nature of the link: a guarantee that no eavesdropping can take place. By placing the entangled photon source on the ground, the space segments contains “only” the less complex detection system, enabling its implementation in a compact enclosure, compatible with the 12U CubeSat standard ( ${\sim}12~\mbox{dm}^{3}$ ). This reduces the overall cost of the project, making it an ideal choice as a pathfinder for future European quantum communication satellite missions. The space segment is also more versatile than one that contains the source since it is compatible with a multiple of QKD protocols (not restricted to entangled photon schemes) and can be used in quantum physics experiments, such as the investigation of entanglement decoherence. Other possible experiments include atmospheric transmission/turbulence characterization, dark area mapping, fine pointing and tracking, and accurate clock synchronization; all crucial for future global scale quantum communication efforts.

中文翻译：

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Nanobob：用于上行链路配置中的量子通信实验的CubeSat任务概念

我们提出了地对空量子密钥分配（QKD）任务概念以及相关低地球轨道纳米卫星有效载荷发展的可行性研究。量子信息由单个光子携带，二进制代码由光子的偏振态表示。纠缠的光子在地面和卫星之间的分布可用于证明链路的量子性质：保证不会发生任何窃听。通过将纠缠的光子源放置在地面上，这些空间段仅包含较简单的较不复杂的检测系统，从而使其可以在紧凑的外壳中实现，并与12U CubeSat标准（$ {\ sim} 12〜\ mbox {dm} ^ {3} $）。这样可以减少项目的总成本，使其成为未来欧洲量子通信卫星任务探路者的理想选择。该空间段比包含源的空间段更通用，因为它与多种QKD协议兼容（不限于纠缠光子方案），可用于量子物理实验，例如纠缠退相干的研究。其他可能的实验包括大气传输/湍流表征，暗区映射，精确指向和跟踪以及精确的时钟同步；所有这些对于未来全球规模的量子通信工作至关重要。该空间段比包含源的空间段更通用，因为它与多种QKD协议兼容（不限于纠缠光子方案），可用于量子物理实验，例如纠缠退相干的研究。其他可能的实验包括大气传输/湍流表征，暗区映射，精确指向和跟踪以及精确的时钟同步；所有这些对于未来全球规模的量子通信工作至关重要。该空间段比包含源的空间段更通用，因为它与多种QKD协议兼容（不限于纠缠光子方案），可用于量子物理实验，例如纠缠退相干的研究。其他可能的实验包括大气传输/湍流表征，暗区映射，精确指向和跟踪以及精确的时钟同步；所有这些对于未来全球规模的量子通信工作至关重要。