What do you think Gordon Cooper's, film crew saw?

In 1957, before he was an astronaut, Gordon Cooper was the supervisor of a crew of 2 men that were filming aircraft at Edwards Air Force Base. Cooper says that the 2 men filmed a flying saucer as it landed about 50 yards away and then it took off without making a sound as they approached for a closer look. The men informed Cooper of what they had seen. Per protocol, Cooper called a special Pentagon phone number to report the incident. Cooper got instructions to develope the film, but not make prints. Cooper saw some of the negatives before he sent them away in a locked courier pouch as instructed. There is more information about the incident and other UFO claims by Gordon Cooper in the section titled "UFO Claims" at:

http://en.wikipedia.org/wiki/Gordon_Cooper