One of the trickiest aspects of the Webb deployment was the unfolding of “its 21-foot [6.4 meters], gold-coated primary mirror,” the hardware that will allow the telescope to do its tricks.
When it launched, the hexagonal mirror was fitted inside the Ariane 5 rocket with its two wings folded together, as to fit inside the fairing. Over the weekend, the mirror expanded to its true size, and now humanity has out there “the largest mirror ever launched into space.”
Although now fully deployed, the telescope still has some fine-tuning to do. As far as the mirror is concerned, its 18 segments will have to move to align the telescope’s optics. 126 actuators located on the backside of each segment will be commanded from Earth to get into position, a process that should take several months.
Once that is done, the telescope’s science instruments will have to be calibrated, and then the fun of unlocking the Universe’s mysteries may begin. And not just any mysteries, but some that are 13.5 billion years old, the distance the Webb can see infrared light, in “much higher resolution than ever before.”
“We are thrilled that the complex telescope unfolding worked successfully. Now we hold our breath for the optics alignment, the instrument commissioning, and finally the fascinating first science results,” said in a statement Prof. Günther Hasinger, ESA Director of Science.