Webb launch timeline at Europe’s Spaceport

The James Webb Space Telescope (Webb) will be the largest, most powerful telescope ever launched into space.

Webb’s flight into orbit will take place on an Ariane 5 rocket from Europe’s Spaceport in French Guiana. As part of the international collaboration agreement, ESA is providing the observatory’s launch service.

The Webb launch campaign of almost 70 days involves a team of more than 100 experts hosted at Europe’s Spaceport. NASA is highly involved, working closely with ESA towards launch.

Webb is large. Though the observatory weighs only six tonnes, it is more than 10.5 m high and almost 4.5 m wide in the folded position. Its shipping container is 30 m long, and with equipment included weighs more than 70 tonnes. Because of this, Webb will come to French Guiana by sea, crossing the Panama Canal to dock in Pariacabo harbour in Kourou. From here, it will be transported by a dedicated truck to Europe’s Spaceport. Ground equipment will arrive by sea and air from around the United States.

The cleanliness requirements are so high that a tent 12.5 m high and 12 m wide will be placed over Webb inside the cleanroom itself, purged at all times with extremely pure air to remove any contamination. Whenever this tent is removed, walls of filters will take over and fans will be switched on. In addition, the fairing and other rocket parts close to Webb will be treated specially to ensure cleanliness.

From liftoff until separation, CNES Launch Range services will track Ariane 5 from ground stations in Kourou, in Ascension Island (South Atlantic), Natal (Brazil), Libreville (Gabon) and Malindi (Kenya).

Immediately after Webb separates from the rocket, ESA's tracking station network, ESTRACK, will follow the Early Orbit Phase operations using its Malindi ground station in collaboration with NASA’s station network.

Webb is an international partnership between NASA, the European Space Agency (ESA) and the Canadian Space Agency (CSA).