The James Webb Space Telescope is launched.

The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. As the largest telescope in space, it is equipped with high-resolution and high-sensitivity instruments, allowing it to view objects too old, distant, or faint for the Hubble Space Telescope. This enables investigations across many fields of astronomy and cosmology, such as observation of the first stars and the formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets.

Ariane flight VA256 was an Ariane 5 rocket flight that launched the James Webb Space Telescope (JWST) into space on 25 December 2021. It was 2021's final Ariane flight, its most valuable payload to date, and the 256th Ariane mission. The launch was described by NASA as "flawless" and "perfect".

December 25 is the 359th day of the year in the Gregorian calendar; six days remain until the end of the year.