The James Webb Telescope will scan the cosmos for light streaming from stars and galaxies formed 13.7 billion years ago. The James Webb Space Telescope has completed a tricky two-week-long deployment phase, unfolding its huge, gold-plated, flower-shaped mirror panel as it readies to study every phase of cosmic history. Engineering teams at the Space Telescope Science Institute in Baltimore, Maryland, cheered on Saturday as NASA announced on Twitter that the final portion of the 6.5-metre (21-foot) mirror was deployed. 

“I’m emotional about it – what an amazing milestone,” Thomas Zurbuchen, a senior NASA engineer, said during the live video feed as stargazers worldwide celebrated.

“We see that beautiful pattern out there in the sky now.”

More powerful than the Hubble Space Telescope, the $10bn Webb will scan the cosmos for light streaming from the first stars and galaxies formed 13.7 billion years ago. To accomplish this, NASA had to outfit Webb with the biggest and most sensitive mirror ever launched – its “golden eye”, as scientists call it.

The telescope is so big that it had to be folded origami-style to fit in the rocket that blasted off from French Guiana two weeks ago.

The riskiest operation occurred earlier in the week when the tennis court-size sun shield unfurled.