While walking back to my campsite at the eaa airventure aviation convention, i noticed an unwavering, solid orange light moving quickly across the sky from my right to my left, west to east, traveling right overhead. i am a student pilot and aviation enthusiast, and am quite familiar with the appearance of aircraft flying at night; as such, it struck me as very strange that there were no red and green navigation lights, and no blinking strobe. furthermore, the airventure convention shuts down flight operations after dark (except for certain scheduled aircraft arrivals). my immediate thought was that it was an r/c aircraft or quadcopter, but it was silent, and seemed to be flying too high and too fast. i would estimate the light altitude at approximately 1,800 feet. the light travelled in a straight line at a constant velocity. i watched it for about one minute, then i pulled out my cell phone and filmed it for 16 seconds. it was becoming hard to track with the screen of my phone, so i continued to watch with just my eyes until finally losing track of the light. i tried to find it again, but i believe i lost it due to distance. the sighting lasted approximately two minutes, and during this time the light never flickered or changed intensity/color. i was quite mystified after watching the light, certain in my belief that it was not a legal/registered flight but uncertain as to what was flying. this is the only flying object that i have seen in my life that i have not been able to identify.