Black knight
One of the clearest and famous UFO sightings happened in space. During the STS-88 mission, the crew saw a strange object outside the spaceship window. They took pictures and reported the object to their mission control. It looked like a black ship was following them.
Up to this day, it isn’t clear what this object was or what it was doing in space so close to the astronauts’ spaceship. It must have been unsettling to have something so close while surrounded by the emptiness of space. Although someone at NASA may know what this is, they would never tell us.