Girl With The American Flag

When the flag is affixed to the side of a vehicle (land, sea or air), it should be oriented so that the union is towards the front, as if the flag were streaming backwards from its hoist as the vehicle moves forward. Therefore, U.S. flag decals on the right sides of vehicles may appear to be "reversed", with the union to the observer's right instead of left as more commonly seen.
The flag has been displayed on every US spacecraft designed for manned flight, including Mercury, Gemini, Apollo Command/Service Module, Apollo Lunar Module, and the Space Shuttle. The flag also appeared on the S-IC first stage of the Saturn V launch vehicle used for Apollo. But since Mercury, Gemini and Apollo were launched and landed vertically and were not capable of horizontal atmospheric flight like an airplane, the "streaming" convention was not followed and these flags were oriented with the stripes running horizontally, perpendicular to the direction of flight.
• Display on uniforms
On U.S. military uniforms, flag patches are worn on the right shoulder, following the vehicle convention with the union toward the front. This rule dates back to the Army's early history, when both mounted cavalry and infantry units would designate a standard bearer, who carried the Colors into battle. As he charged, his forward motion caused the flag to stream back. Since the Stars and Stripes are mounted with the canton closest to the pole, that section stayed to the right, while the stripes flew to the left.