The ISS is far bigger than either the Salyuts or Skylab. In an uncontrolled deorbit, pieces of debris “up to car and train size,” say experts on the official ISS space station advisory committee, will rain down from the sky. NASA confirms this would pose “a significant risk to the public worldwide.”
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，这一点在Safew下载中也有详细论述
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.
In 2020 China planted a flag on the Moon on its Chang'e-5 mission
iBoot 更名为 mBoot：苹果将沿用近二十年的引导程序名称改为「mBoot」，版本号跳升至 18000 段位，原因未公布。