In a mission in preparation for more than two decades, NASA on Saturday launched the most expensive science probe ever built, a $ 10 billion telescope that will attempt to capture starlight from the first galaxies to be born in the Big Bang flaming crucible.
Billions over budget and years behind schedule, the James Webb Space Telescope finally lifted off on Christmas Day, departing from the European Space Agency’s launch site in Kourou, French Guiana, at 7:20 a.m. EST in top of an Ariane 5 rocket.
The European workhorse, built by Arianespace as part of ESA’s contribution to Project Webb, provided a spectacular holiday spectacle, moving away from its launch site in the jungle on the northeast coast of the South America across a cloudy sky.
Accelerating through the sound barrier 47 seconds after take-off, the Ariane 5 quickly emerged from the thick lower atmosphere, disposing of its two solid-fuel boosters along the way.
The first-stage Vulcain 2 hydrogen engine stopped 8 and a half minutes after launch, and the flight continued for an additional 16 minutes using power from the rocket’s second cryogenic stage.
Then, 27 minutes after launch, at an altitude of about 865 miles above the eastern coast of Africa, the James Webb Space Telescope was released to stand on its own, outward at over 21,000 mph.
“Come on, Webb! Exclaimed a mission controller as the team burst into applause.
Still folded up to fit inside Ariane 5’s nose cone, the observatory’s unique solar panel, essential for starting to recharge the spacecraft’s batteries, deployed on computer command moments after separation, clearly visible in downlink video from a camera on the top stage of the rocket.
Minutes later, NASA reported that Webb was on, communicating with flight controllers, and was correctly oriented in relation to the sun with its six gyroscope-like stabilizing reaction wheels operating normally.
“This is a great day, not only for America, for our European and Canadian partners, but it is a great day for planet Earth,” said NASA Administrator Bill Nelson, speaking since. the Kennedy Space Center.
He congratulated the thousands of men and women who built and launched the telescope, saying that “you have all been amazing and in three decades you have produced this telescope which will now take us back in time.”
“It’s a time machine, it’s going to take us back to the very beginnings of the universe,” he said. “We are going to discover incredible things that we never could have imagined.”
While it may seem like a stretch, Nobel Prize winner Adam Riess, who used theTo help confirm the existence of a mysterious dark energy, Webb will live up to those high expectations if it works.
“If the mission is successful, then I don’t think we’re overdoing it,” he said. “I mean, all I can do is compare it to Hubble. Even if it’s only half as transformative as Hubble, (you) wouldn’t overestimate it.”
It will take Webb a full month to reach his orbital parking lot in deep space a million kilometers from Earth – known as Lagrange Point 2, or L2 – where he can circle the sun in gravitational synchronization with Earth, thereby minimizing fuel consumption to extend its life. as long as possible.
With a near-perfect launch, a thruster firing Saturday night to fine-tune Webb’s trajectory may require less fuel than expected, helping to extend the operational life of the telescope.
“It was a great moment on Christmas Day,” said Josef Aschbacher, Director General of the European Space Agency, of the launch. “The whole world watched this, and I’m very happy to say that the Europe team delivered. We put the spacecraft very precisely in orbit in terms of altitude, speed, tilt (orbital).”
The telescope is optimized to capture images of the first stars and galaxies to start shining in the aftermath of the Big Bang, a light that has been extended into the infrared portion of the spectrum by the expansion of space itself over the past 13 , 8 billion years.
This light cannot be seen by the iconic Hubble, which Webb will eventually replace. Hubble was designed to study the wavelengths of visible light, but even so, it hasdating back less than half a billion years after the Big Bang.
Webb should be able to push several hundred million years beyond, detecting the light that started to come out when the universe was only around 200 million years old. This is the time when the cosmos first emerged from the hydrogen fog of birth and starlight began to travel freely through space.
The long-awaited baby images of the universe are expected to shed a revolutionary light on the formation and evolution of galaxies, the supermassive black holes that lurk in their hearts and the lifecycles of stars from birth to titanic explosions of supernova that have prepared. most of the elements of the periodic table.
Closer to home, Webb will also study the atmospheres of planets orbiting nearby stars to characterize their habitability and provide up-close and routine looks at planets, moons, asteroids and comets in the Earth’s solar system. Mars to the distant Kuiper Belt beyond Neptune.
Lagrange Point 2 is well beyond the reach of any predictable astronaut repair crew, but it’s a great place to reach the ultra-low temperatures required to detect infrared emissions from the infant universe.
But orbit alone is not enough to cool Webb to about 50 degrees above absolute zero.
In order for the telescope’s 21.3-foot-wide primary mirror and its four sensitive instruments to detect this weak heat, Webb must first deploy and stretch a tennis court-sized umbrella to block out light and emissions. thermals of the Sun, Earth and Moon.
It is considered by many to be the riskiest part of the mission, including the launch.
Over 100 electrically activated mechanisms, used to hold the parasol’s five thin Kapton layers in place during launch vibration and the onset of weightlessness, all need to fully unlock so the membranes can be pulled off the poles as intended. .
Each layer must then be stretched and separated by motorized cables passing through dozens of pulleys.
If this all sounds complicated, it is. If that sounds unusually risky, it is.
“The sun visor is where a lot of the deployment risk exists because that’s where so many point failures exist, and it’s just complicated,” said Paul Geithner, deputy project manager.
“We have 107 small non-explosive actuators, diaphragm release devices… That’s where a lot of the risk of deployment is because it’s a lot of parts. These are simple mechanics, but there are a lot of them and they are all I have to work on. “
The deployment of the sunshade is scheduled to begin on December 28 and if all goes well the process will be complete by January 2.
Next is the deployment of Webb’s 21.3-foot-wide segmented primary mirror, the largest ever built for an instrument in space. Like the sun visor, the mirror had to be folded up to fit Ariane 5’s nose.
Starting approximately 10 days after launch, six of the 18 hexagonal mirror segments, three on each side, will be unfolded and locked in place. Each segment can be tilted and tilted as needed to achieve precise focus, a process that will take months.
Throughout deployments and the commissioning process, Webb will continue to slowly cool down to the required operating temperature. If all goes well, the first scientific images are expected around six months after launch.
“All of these one-off failures, all of these deployment mechanisms has to go straight to make a telescope, there’s no middle ground,” said Mark McCaughrean, senior science and exploration advisor at the Space Agency. European Union, in an interview with Spaceflight. Now.
“If the sunshield only half deploys, the telescope never cools, the instruments don’t turn on. So that’s the nerve-racking time, that first month. And after that, the five months. cooling and commissioning, then we can start to do science. “