- Inside the Apollo “8-Ball” FDAI (Flight Director / Attitude Indicator) (righto.com)
During the Apollo flights to the Moon, the astronauts observed the spacecraft’s orientation on a special instrument called the FDAI (Flight Director / Attitude Indicator). This instrument showed the spacecraft’s attitude—its orientation—by rotating a ball. This ball was nicknamed the “8-ball” because it was black (albeit only on one side). The instrument also acted as a flight director, using three yellow needles to indicate how the astronauts should maneuver the spacecraft. Three more pointers showed how fast the spacecraft was rotating.
- Quarry (Wikipedia)
A quarry is a place where rock and earth materials – such as limestone, marble, granite, gravel, and sand – are excavated. The operation of quarries is regulated in some jurisdictions to manage their safety risks and reduce their environmental impact.