James Webb Space Telescope successfully opens its gold-plated, flower-shaped mirror panel

The James Webb Space Telescope has completed its 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 cheered back at the Space Telescope Science Institute in Baltimore, Maryland 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 on Saturday as stargazers worldwide celebrated.

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

More powerful than the Hubble Space Telescope, the $10 billion 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.

Because the telescope was too large to fit into a rocket’s nose cone in its operational configuration, it was transported folded-up.

Unfurling has been a complex and challenging task the most daunting such project ever attempted, according to NASA.

The Webb blasted off in an Ariane 5 rocket from French Guiana on December 25, and is heading to its orbital point, 1.5 million km from Earth.

Though Webb will reach its space destination, known as the second Lagrange point, in a matter of weeks, it still has about another five and a half months of setup to go.

The next steps include aligning the telescope’s optics, and calibrating its scientific instruments.

If all continues to go well, science observations will begin this summer. Astronomers hope to peer back to within 100 million years of the universe-forming Big Bang, closer than Hubble has achieved.

Its mission also includes the study of distant planets to determine their origin, evolution, and habitability.

The NASA telescope blog said Saturday’s procedure was “the last of the major deployments on the observatory”.

“Its completion will set the stage for the remaining five and a half months of commissioning, which consist of settling into stable operating temperature, aligning the mirrors, and calibrating the science instruments.”