Satellites are the most efficient way to achieve global scale quantum communication (Q.Com) because unavoidable losses restrict fiber based Q.Com to a few hundred kilometers. We demonstrate the feasibility of establishing a Q.Com uplink with a 3U CubeSat, measuring only 10 × 10 × 34 cm3, using commercial off-the-shelf components, the majority of which have space heritage. We demonstrate how to leverage the latest advancements in nano-satellite body-pointing to show that our 4 kg CubeSat can generate a quantum-secure key, which has so far only been shown by a much larger 600 kg satellite mission. A comprehensive link budget and simulation was performed to calculate the secure key rates. We discuss design choices and trade-offs to maximize the key rate while minimizing the cost and development needed. Our detailed design and feasibility study can be readily used as a template for global scale Q.Com.

中文翻译：

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Q ³ Sat：量子通信上行到3U CubeSat的可行性和设计

卫星是实现全球规模量子通信（Q.Com）的最有效方法，因为不可避免的损耗将基于光纤的Q.Com限制在数百公里之内。我们演示了使用商业化的现成组件（其中大多数都具有太空遗产）与3U CubeSat（尺寸仅为10×10×34 cm3）建立Q.Com上行链路的可行性。我们演示了如何利用纳米卫星人体指向的最新进展来表明我们的4千克CubeSat可以生成量子安全密钥，到目前为止，只有更大的600千克卫星任务才能证明这一点。进行了全面的链路预算和模拟，以计算安全密钥率。我们讨论设计选择和权衡，以最大程度地提高密钥率，同时最大程度地减少所需的成本和开发。