Webb has been confirmed as being go for launch, and the countdown clock was started! With weather reports looking favorable, the team authorized fueling of the Ariane 5, which began at 3 am EST.
Arianespace will measure winds at high altitude with the help of balloons to ensure absolute safety for the launch. Meanwhile the team continues to monitor Webb which is kept in a stable condition in the fairing. The team is monitoring temperatures, relative humidity, and cleanliness of the air entering the fairing – critical parameters to keep Webb cool, dry, and clean before liftoff.