Update: 4:30 p.m. EST, Dec. 21, 2021:
NASA and Arianespace successfully completed the Launch Readiness Review for the James Webb Space Telescope on Dec. 21. The team authorized the Ariane 5 rocket carrying Webb to rollout and the start of launch sequencing for the mission.
However, due to adverse weather conditions at Europe’s Spaceport in French Guiana, the flight VA256 to launch Webb – initially scheduled for Dec. 24 – is being postponed.
The new targeted launch date is Dec. 25, as early as possible within the following launch window:
- Between 7:20 a.m. and 7:52 a.m. Washington
- Between 9:20 a.m. and 9:52 a.m. Kourou
- Between 12:20 p.m. and 12:52 p.m. Universal (UTC)
- Between 1:20 p.m. and 1:52 p.m. Paris
- Between 9:20 p.m. and 9:52 p.m. Tokyo
Tomorrow evening, another weather forecast will be issued in order to confirm the date of December 25. The Ariane 5 launch vehicle and Webb are in stable and safe conditions in the Final Assembly Building.