James Webb Space Telescope has finished unfolding its massive mirror

Alex Wilkins

An artist's impression of a telescope.

Adriana Manrique Gutierrez is a NASA GSFC/CIL.

The telescope is complete. Over the weekend, its primary mirror, made of gold-plated hexagonal reflectors, was put in place.

The mirror is the final step in the unfurling process after it was packed and launched from French Guiana on 25 December. The most advanced telescope ever put into space will be able to see further back into the universe than before, and will be able to image the first stars.

It was a smooth operation to unpack. On 4 January, the operators of the JWST completed their most critical maneuver, the unfolding and tensioning of the sun shield, which protects the telescope from the sun's powerful radiation.

On 5 January, the secondary mirror was extended out in front on three long poles, before the primary mirror unfolded on 8 January, marking the end of major deployment.

There are still some things that need to be done before the JWST arrives at its destination, 1.5 million kilometres from Earth.

The story of the universe will be rewritten by the James Webb telescope.

The telescope needs to make a third course correction burn to push it into L2. Thanks to the accuracy of the Ariane 5 rocket, the first two course corrections used less fuel than expected. NASA engineers say the JWST should last longer than expected. The third burn, scheduled for late January, is hoped to go as smoothly as the first two.

The telescope mirrors need to be adjusted. NASA engineers will move 126 mirror motors over the course of several months. The scientific instruments will be ready to image the deep universe in May or June of this year once the alignment is complete.

The complex telescope unfolding worked well, said Gnther Hasinger at the European Space Agency. The fascinating first science results, the optics alignment, and the instrument commissioning are all waiting for us.

The telescope will cool itself to an operating temperature of -223C when it moves into position. We have never seen stars and planets like they are in the space portion of the spectrum.

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