恒久飞行的飞机孙文德编译美国工程师们一直在研制一种能昼夜飞行而不需着陆的恒久飞机。这并非别出心裁，因为这种飞机可以完成现在只能用卫星来完成的工作，而且代价比卫星低得多。机载的仪器设备在磨损或过时后可以更换，而卫星上的设备无法更换，而且在太空中工作的设... Permanent flying aircraft Sun Wende compiled American engineers have been developing a permanent flight that can fly day and night without landing. This is no exception, as the aircraft can do what it can now do with satellites and at a much lower cost than satellites. Airborne equipment can be replaced after wear or out of date, while equipment onboard satellites can not be replaced and work in space ...