Red high altitude light disappeared after 5 seconds and never reappeared.Singular red light. Extreme high altitude, "low orbit?" Northbound heading toward Ursa Major. Thought it was a satellite at first when it disappeared about five seconds after spotting it. No port or starboard lights that an aircraft would have. Besides it disappearing and never reappearing, its clearly red color made the object abnormal. I know aircraft and high/low orbit spacecraft. This was not one.