The lights of space shuttle mission STS-48
The account
A NASA camera supposedly caught craft changing course after a flash, as if fleeing a weapon being fired.
What investigators found
The most widely accepted explanation involves ice particles and debris lit by the Sun, pushed by the firing of the shuttle's thrusters.
The story
In September 1991, a camera aboard the space shuttle Discovery, on mission STS-48, recorded bright points floating above Earth's horizon. At one point there is a flash, and several of those points seem to change direction abruptly, one of them speeding away. The clip became a UFO classic.
Some analysts argued that the objects were far away and moving intelligently. The most widely accepted explanation is far more mundane. Spacecraft in orbit constantly shed tiny ice particles and debris, which glow when struck by sunlight. The flash would coincide with the firing of an attitude control thruster, whose jet pushes those nearby particles and changes their path. With no sense of distance, tiny fragments close by look like large objects far away.