The James Webb Space Telescope has achieved another major milestone today, successfully extending its secondary mirror as it continues to sail through its never-before-conducted deployment sequence on the way to its destination.
The secondary mirror is attached to a tripod and sits opposite the main mirror. The main mirror has a gold coating on it and it's job is to concentrate the light from it into an opening at the center. The light reaches the third mirror, which reflects it to the telescope's instruments.
The main mirror has a secondary mirror stowed on top of it and attached to three legs.
The legs in place during the launch were secured by a set of latches released by operators at the Space Telescope Science Institute in Baltimore. After performing a small move to make sure the motors worked well, they began the deployment procedure, which saw the legs extend and fall into place over the course of 10 minutes. The maneuver was streamed live on NASA's TV channel.
An astronomer explains how to send a giant telescope to space.
The animation shows how light is reflected from the mirrors onto the instruments. The image is from NASA.
The mirror was confirmed at 11:30 a.m. The time is 1630 GMT. The operators took another 30 minutes to lock the tripod in place and make sure it wouldn't fall apart.
This is unbelievable. Bill Ochs, the project manager for the James Webb Space Telescope at NASA's Goddard Space Flight Center in Maryland, said in the webstream that we are 600,000 miles from Earth and have a telescope. "So thank you to everybody."
"After it's latched, it's complete, and we don't ever come back and adjust this again," said Julie van Campen, the deputy commission manager.
The operators completed the unfurling and tensioning of the telescope's sun shield a day before the secondary mirror deployment.
The telescope operators will put a cooling system on the back of the telescope on Thursday. The main mirror had to be folded for launch due to its large size.
The first 12 days after the launch were devoted to the deployment of the subsystems. We moved to the optical elements of the telescope today. The final part of the commission will focus on the science instruments.
The operators of the telescope can use a visualization tool to see the deployment of the observatory. The image is from NASA.
The telescope's deployment sequence was a source of apprehension for some. To see the first stars and galaxies that formed in the universe in the first hundreds of millions of years after the Big Bang, required an observatory of an unprecedented size and complexity. The telescope is so large that no existing rocket could launch it without folding it up first. Engineers and technologies were stretched to their limits by the mission. The solutions that see the telescope self-assembling in space have never been used before. The testing program that took years to complete is paying off.
Over the past 12 days, it has worked very well. We have had moments of excitement and tension as we wait to see how things work out. It's been going well and we are ahead of schedule.
The telescope will not be ready for science until this summer. It will take more than 100 days for the temperature of the building to cool down. The telescope will only be able to detect the faintest signals from the most distant stars in the most extreme cold.
Operators can't see what's happening visually because existing camera technology wouldn't survive in the cold. Scientific observations could be affected by electronic interference from the cameras. Operators use a visualization tool to see the data from the telescope.
The telescope is on its way to the Earth-sun Lagrange Point 2, some 1.5 million km away from our planet. The sun is hidden behind Earth and held in a stable position by the interplay of the two bodies.
The telescope will be fully deployed by the end of January. The $10 billion space observatory is expected to provide previously impossible insights into star and planet formation, the chemistry of exoplanets and the behavior of comets and asteroids at the outer fringes of the solar system.
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