system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can the Hubble Space Telescope keep its lens pointed in the same spot to take long exposure shots when it's orbiting the Earth every 97 minutes?
gpt
Hubble uses six gyroscopes to know exactly where it's pointing. These are devices that act a bit like a compass, and always point in the same direction even when the telescope is orbiting.

Next it has four reaction wheels which actually move the telescope. These just use Newton's 3rd law of motion; if the wheel spins one way then the telescope spins the other.

Finally when it's observing, an instrument called the Fine Guidance Sensor will lock on to nearby stars, and make sure the telescope stays precisely pointed in the same direction/orientation.