Spy planes might be the reason many people believe UFOs exist. From Space-bordering altitudes to designs fit for a sci-fi movie, these aircraft may look аɩіeп from a distance.

Spy planes exist so militaries wouldn’t have to be moving blindly. And although most modern aircraft are fitted with stealth tech and some level of intelligence-gathering capabilities, spy planes remain the original aircraft designed for these purposes.

From the U-2 spy plane of the Cold wаг eга to a purely experimental Star-Trek-inspired aircraft from the ’90s, here are 5 intriguing spy planes that have shaped modern aviation.