Still others would stand as sentinels in high earth orbit to spot dangerous intruders from our star.

还有一些将作为地球高轨上的哨兵来确定危险入侵者距离我们这个星球的准确位置。

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Combined environment which consists of charged particle radiation and ultraviolet (UV) radiation exists in the medium and high Earth orbit.

在中高轨道上，存在着带电粒子辐射、紫外辐照等组成的综合辐射环境。

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On the aspect of observation time, it has limited efficiency for low earth orbit target space-based observation, and good efficiency for high earth orbit observation.

在可见时间方面，天基空间目标光学监视系统对低轨目标的监视能力有限，而对高轨目标具有良好的监视性能。

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The 13-tonne mission was initially lifted into a 350km-high orbit above Earth, with the expectation that the probe's big engine would fire twice - first, to raise that orbit, and, second, to set course for Mars.

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But unlike Iridium's 66 low-orbit birds, Astrolink will cover the earth with only four high-orbit geostationary fliers.

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This is opening new opportunities for even high school students and hobbyists to launch satellites into low earth orbit and dream of going there themselves.

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