Breakaway (Space: 1999)

Breakaway refers to the cataclysmic event that occurs in the science fiction television series Space: 1999, marking the beginning of the main storyline. On September 13, 1999, the nuclear waste storage facilities on the Moon, used by Earth to dispose of its radioactive waste, reach a critical mass. This critical mass leads to a chain reaction explosion of immense power.

The explosion is not a conventional blast, but a series of rapid nuclear detonations resulting in a massive release of energy. This energy pulse propels the Moon out of Earth orbit, sending it hurtling through space at incredible speed. All 311 inhabitants of Moonbase Alpha, a lunar research facility, are marooned aboard the Moon as it becomes a rogue planet traveling through the galaxy.

The Breakaway event serves as the inciting incident for the series, setting the stage for the Alphans' long and perilous journey through the cosmos, encountering alien civilizations, phenomena, and dangers as they struggle to survive. The specifics of the Breakaway and its effects on the Moon are often debated and inconsistent within the series, but its central role as the reason for the Moon's interstellar voyage remains constant.