On-board viewing methods changed over the decades. Gemini astronauts literally sat by their windows because their cabin was too small to move away. The Apollo era saw larger vehicles in which busy astronauts spent less time actually looking out windows. By the time the space shuttles came along, their magnificent windows were frequently used for astronaut sightseeing. But the craft also sported an impressive array of television cameras in their payload bays and on their robot arms.
White dots crisscross the earth, horizon and star-filled sky.
Some appear out of nowhere, or abruptly change direction. The notorious STS 48 and STS 80 videos, for example, share some common factors not known to amateur investigators, and these factors provide convincing proof of their routine nature. In both cases, the shuttle has just emerged from Earth's shadow and the camera is peering backwards toward the still-dark Earth to spot lightning bursts. The shuttle is bathed in bright sunlight, but since it's in vacuum, this light is invisible except as it illuminates nearby particles. Some particles that happen to be closer to the camera drift away and pass out of the shuttle's shadow, making them suddenly visible.