One reason for routinely launching GPS satellites is simply "constellation replenishment," said Col. Andrew Menschner, deputy commander of the Space Force's Space Systems Command. Old satellites degrade and die, and new ones need to go up and replace them. At least 24 GPS satellites are needed for global coverage, and having additional satellites in the fleet can improve navigation precision. Today, there are 31 GPS satellites in operational service, flying more than 12,000 miles (20,000 kilometers) above the Earth.
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，更多细节参见heLLoword翻译官方下载
南方周末：这么密集的一段演出期，对你来说更多是一种兴奋，还是一种消耗？
「我覺得就像每一個進入中國的外國人一樣，因為我喜歡攝影，我很喜歡在中國拍攝辛苦的勞工、地攤市場上的毛澤東畫像、紅色五角星，我得說我覺得我趕在『成為中國人』這個潮流走紅之前就在學習『成為中國人』，」安迪這樣告訴BBC中文，打趣稱在他回國後，很多朋友都問他是否有成為「黨員」、打算作為「間諜」效忠北京。
Qatar GP — April 12