The flight test was conducted in the challenging highaltitude environment required for refueling of high altitude long endurance (HALE) unmanned aircraft systems (UAS).
It's the basic physics that the air is thinner and the resistance to any projectile is less so the flight path of the ball will be different at highaltitude.
基本物理学理论上,空气越稀薄情况下,任何物体的耐性都会减少,因此球路也会因海拔高度不同而有所变化。
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The trial was conducted at the company's Airbreathing Test Facility in Orange County, Virginia, and involved a full-scale engine tested at conditions simulating high-altitude, high-speed flight.