Space seems empty and therefore the perfect environment for radio communications. Don't let that fool you: There's still plenty that can disrupt radio communications. Earth's fluctuating ionosphere can impair a link between a satellite and a ground station. The materials of the antenna can be distorted as it heats and cools. And the near-vacuum of space is filled with low-level ambient radio emanations, known as cosmic noise, which come from distant quasars, the sun, and the center of our Milky Way galaxy. This noise also includes the cosmic microwave background radiation, a ghost of the big bang. Although faint, these cosmic sources can overwhelm a wireless signal over interplanetary distances. · Depending on a spacecraft's mission, or even the particular phase of the mission, different link qualities may be desirable, such as maximizing data throughput, minimizing power usage, or ensuring that certain critical data gets through. To maintain connectivity, the communications system constantly needs to tailor its operations to the surrounding environment.

中文翻译：

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以前没有无线电的地方：即使面对外星环境，认知无线电也可以使深空任务与地球保持联系

空间似乎是空的，因此是无线电通信的完美环境。不要让这愚弄你：仍然有很多东西会干扰无线电通信。地球波动的电离层会损害卫星和地面站之间的链接。天线的材料在加热和冷却时会变形。近乎真空的太空充满了低水平的环境无线电辐射，称为宇宙噪声，它们来自遥远的类星体、太阳和我们银河系的中心。这种噪音还包括宇宙微波背景辐射，即大爆炸的幽灵。虽然微弱，但这些宇宙源可以压倒行星际距离上的无线信号。· 根据航天器的任务，甚至任务的特定阶段，可能需要不同的链路质量，例如最大化数据吞吐量、最小化电源使用或确保某些关键数据通过。为了保持连通性，通信系统需要不断地根据周围环境调整其操作。