A little more than two weeks ago, the most powerful space observatory ever built roared into the sky, carrying with it the hopes and dreams of an entire generation of astronomers, all contained within a tightly wrapped package of mirrors, wires, motors, cables, latches, and wispy sheets of thin plastic, all of which were encircled by a pillar of smoke and fire.
The observatory, the James Webb Space Telescope, accomplished a last, critical step on Saturday morning about 10:30 a.m. by unfolding the final segment of its golden, hexagonal mirrors, which was previously closed. After almost three hours, engineers were able to send orders to the mirrors to secure them in position, thereby completing the mission’s entire deployment, according to the space agency.
It was the most recent in a series of delicate movements involving 344 “single points of failure” while travelling at high speed across space, according to the space agency’s count. Now, the telescope is nearly ready to begin operations, albeit there will be some anxious times in the near future.
“I’m a little sentimental about it,” Thomas Zurbuchen, NASA’s scientific head, said of the telescope’s mirrors finally falling into position. “I’m a little emotional about it,” he said. “What an incredible achievement – we can see that gorgeous design up there in the sky that is nearly completely completed.”
Twenty-five years and $10 billion have gone into the construction of the James Webb Space Telescope, which is named after a former NASA administrator who handled the early years of the Apollo programme. As a result, it is three times larger than the Hubble Space Telescope and is intended to view farther back in time than its famed predecessor in order to investigate the earliest stars and galaxies to shine in the early stages of the universe’s history.
According to NASA Goddard mission systems engineer Mike Menzel, the launch of an Ariane rocket on the morning of December 25 was flawless; in fact, the engineers believe it saved enough manoeuvring fuel to allow the mission’s estimated 10-year lifetime to be extended by as much as an additional 10 years. However, the telescope must travel for more than a month to a location a million miles above the Earth and well beyond the moon’s orbit, known as L2, where the gravitational fields of the Earth and the sun combine to provide the conditions necessary for a stable orbit around the sun.
With a main mirror that measured 21 feet wide, the Webb was too large to fit aboard a rocket. As a result, the mirror was constructed in pieces, consisting of 18 gold-plated hexagons that were folded together and then sprang into place once the telescope was in orbit.
It was also difficult to make the telescope’s equipment sensitive to infrared or “heat radiation,” which is a kind of electromagnetic radiation that is undetectable to the human eye. A result of the universe’s expansion, the most distant and oldest galaxies are fleeing away from us at such a rapid rate that the visible light from those galaxies changes into longer infrared wavelengths. As a consequence, the Webb will be able to observe the cosmos in hues that have never before been seen by the human eye.
As a result of high temperatures being observed on an onboard motor that was only utilised during the deployment procedure, engineers redirected the telescope on Sunday in order to shield the equipment from the sun’s radiation. Later, when engineers discovered that the telescope’s power reserves were less than projected, they had to make adjustments to the solar arrays on the Webb.
One of the most perilous moments occurred on Tuesday, when a gigantic sunscreen the size of a tennis court was successfully unfolded without incident. Its purpose was to maintain the telescope in the dark and cold enough so that the heat generated by the telescope would not interfere with the heat detected from distant stars. Although the screen is comprised of five layers of a plastic known as Kapton, which is identical to Mylar and just as fragile, it has been known to tear during rehearsals for its deployment.
According to Jane Rigby, a project scientist for the mission at NASA Goddard, the initial photographs taken during the mirror alignments will be fuzzy and unsightly. Rigby spoke at a press conference on Saturday and predicted that the first images would be blurry and unsightly. However, she believes that once the mirrors are persuaded into functioning together, the views from the telescope would “blow everyone’s socks off,” according to her.
