An artist's depiction of the James Webb Space Telescope.
NASA.
The James Webb Space Telescope, which is a million miles from Earth, has begun the key task of unfurling a giant umbrella-like shield to protect its delicate instruments from the intense radiation of the sun.
The successful lowering of two arms known as utilized pallet structures began the deployment of the shade on Tuesday.
They have five ultra-thin membranes made of a shiny material called Kapton packed inside along with the cables and pulleys needed to deploy. The process of unfolding the shield is expected to continue through the weekend.
The mission operations team was able to put the forward pallet in place by early Tuesday afternoon after four hours of work.
The Hubble Space Telescope is the successor to it and was launched on Christmas Day. The new scope's primary mirror is six times larger than Hubble and it is expected to be able to gather more light than Hubble.
The older Earth-orbiting observatory is about 100 times as powerful as the new one. That means it will be able to see a lot more. The ability to see objects that were largely hidden to Hubble is thanks to the tuning of the telescope.
Light travels incredibly fast, but it still takes time to travel from a star to our telescopes. The longer it takes for the light to reach us, the more it will take. This means telescopes view objects the same way they used to be, millions or even billions of years ago. It will be able to see all the way back to the time when the first galaxies formed after the Big bang because of the sensitivity of the telescope.
The deployment of the sun shield will keep the temperature of the instruments just above absolute zero, which in turn will minimize the noise from the sun.
The main mirror assembly of the James Webb Space Telescope was tested in California last year.
Chris Gunn is a person.
The sun shield maneuver is being performed as the sun and moon are in balance, providing a stable observing post. It will take about a month.
The telescope's primary mirror is assembled from 18 smaller gold-coated hexagonal mirrors made of beryllium. They will stretch more than 21 feet across once fully aligned.
The Hale Telescope at Mount Palomar, Calif., was the largest such instrument in the world for 45 years after its completion in 1948. Hale's mirror was 200 inches in diameter.
