The James Webb Space Telescope lifted off on an Ariane 5 rocket from Europe’s Spaceport in French Guiana, at 13:20 CET on 25 December 2021 on its exciting mission to unlock the secrets of the Universe.

This timelapse shows highlights of the launch campaign from the arrival of Webb in French Guiana through to liftoff.

Every launch requires meticulous planning and preparation. For Webb, this process began about 15 years ago. Webb arrived from California on board the MN Colibri which sailed the Panama Canal to Pariacabo harbour in French Guiana. The shallow Kourou river was specially dredged to ensure a clear passage and the vessel followed high tide to safely reach port on 12 October 2021.

Though the telescope weighs only six tonnes, it was more than 10.5 m high and almost 4.5 m wide when folded. At Europe’s Spaceport it was unpacked inside a dedicated spacecraft preparation facility fitted with walls of air filters to protect the telescope from contamination during preparations for launch.

After its arrival in the final assembly building, Webb was lifted slowly about 40 m high and then carefully manoeuvred on top of Ariane 5 - one of the most delicate operations during the entire launch campaign. A ‘shower curtain’ about 12 m high and 8 m in diameter was installed in between two platforms, to create a closed-off space around Webb to avoid any contamination.

On the day of encapsulation, the fairing was lowered over the observatory and locked in place for liftoff. A laser guiding system assisted this particularly delicate operation for a perfect fit inside Ariane 5’s fairing.

Ariane 5 with Webb was rolled out from the final assembly building to the launch pad on 22 December. On 25 December, Ariane 5 performed the flawless launch of this once in a generation mission. Ariane 5’s highly precise launch meant that Webb saved its own fuel which can be used to significantly extend its expected lifetime of 10 years.

Webb is the largest, most powerful telescope ever launched into space. As part of an international collaboration agreement, ESA has provided the telescope’s launch service using the Ariane 5 launch vehicle. Working with partners, ESA was responsible for the development and qualification of Ariane 5 adaptations for the Webb mission and for the procurement of the launch service by Arianespace. ESA has also provided the workhorse spectrograph NIRSpec and 50% of the mid-infrared instrument MIRI, in collaboration with the University of Arizona. Webb is an international partnership between NASA, ESA and the Canadian Space Agency (CSA).