NASA’s “all or nothing” gamble on the Webb telescope

A type of cosmic sunrise occurred over 13.5 billion years ago. This early light shone in the universe from the stars and galaxies that came into existence after the Big Bang.
The ancient star’s light kept traveling ever since. And now, with NASA’s James Webb Space Telescope launching on Christmas Eve, astronomers are hoping to catch up. The Webb Telescope, behind the Hubble Space Telescope, will orbit the sun, focusing on a small portion of deep space, looking for this faint light dating back about 300 million years from the Big Bang.
Staring into deep space is like looking back in time. Sunlight takes eight minutes to reach us, so we always see it as it appeared eight minutes ago. Also, glancing at the more distant galaxies would be like seeing snapshots of the infant universe.
“Webb is a time machine, allowing us to take a look at how some of the first galaxies formed to help us understand our cosmic origins,” says Maggie Adrien Pocock, a British astronomer who worked on the telescope. “It collects infrared light that can penetrate through dust clouds that cannot Optical devices see through.
This infrared power is fundamental: as starlight streaks through a vast and expanding universe, it stretches like a loose spiral wire. Light that began as ultraviolet or visible radiation is shifted toward the longer-infrared wavelength portion of the spectrum. This phenomenon is known as redshift.
And unlike Hubble, which mainly monitors light and ultraviolet wavelengths, Webb should be able to detect highly redshifted light from a young universe. It will also search for potentially habitable planets around distant stars.
These ambitions hinged on the perfect execution of one of the most daring astronomical projects ever. The Webb mirror is so large – 6.5 meters in diameter, more than twice the size of the Hubble mirror – that it must be folded to launch and open into space. In addition, the telescope must operate in extremely cold conditions to avoid capturing infrared radiation from other heat sources, such as the Earth and the sun.
To this end, the Webb telescope will travel to a location 1.5 million kilometers from Earth known as Lagrange Point II, or L2. At this point, the Sun, Earth and the telescope will be aligned. Upon arrival, the telescope will deploy a sunshade the size of a tennis court to block radiation from both objects. If that umbrella counts as sunscreen, it will have an SPF of one milligram.
And unlike the Hubble telescope, which orbits Earth close enough to warrant the task of repairing it when its mirror is found to be faulty, the Webb telescope would be a gamble for complete success or failure where everything should go according to plan. After the spacecraft carrying the telescope reaches its orbital position, the mirror-like 18kt gold-plated hexagonal piece must be perfectly aligned to provide the perfect ultra-smooth surface for assembly. The bonding between them will be coordinated by a set of actuators capable of making precise adjustments to the size of a hair of the human body. Then the canopy made of fabric that will be used to block the sun should be opened without ripping. Even before that, Adrienne Pococke admits, she’ll “feel a little scared… We’ll have a month of waiting while the spacecraft makes this flight.”
The Hubble telescope changed space science, helping to date the Big Bang, which occurred about 13.8 billion years ago. It also revealed black holes in the depths of galaxies. He provided us with iconic images of stellar nurseries, such as the Eagle Nebula. It is now up to the James Webb Space Telescope, named after the NASA administrator who was entrusted by President John F. Kennedy with directing the Apollo program, to complete some unfinished business on the birth of the universe.