NASA’s new space telescope opened its huge, gold-plated, flower-shaped mirror on Saturday, the final step in the observatory’s dramatic unfurling.

The last portion of the 6.5-metre mirror swung into place at flight controllers’ command, completing the unfolding of the James Webb Space Telescope.

“I’m emotional about it. What an amazing milestone. We see that beautiful pattern out there in the sky now,” said Thomas Zurbuchen, NASA’s science missions chief.

More powerful than the Hubble Space Telescope, the $10-billion US Webb will scan the cosmos for light streaming from the first stars and galaxies formed 13.7 billion years ago.

Engineering teams celebrate