The National Aeronautics and Space Administration (NASA) has 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 fiery crucible of the Big Bang, in a mission that has been in the works for more than two decades.
By Muhammad Shahid
NASA created the James Webb Space Telescope (JWST) with cooperation from the European Space Agency and Canadian Space Agency. The Webb telescope named after the James E. Webb (American government official), who served as NASA’s administrator from 1961 to 1968 and was a key figure in the Apollo space programme. JWST is a hundred times more powerful than the Hubble Telescope and is slated to take over as NASA’s flagship astrophysics project from the Hubble Telescope.
It will enable us for a wide range of investigations across the fields (cosmology & astronomy), including observations of the most distant objects and the events in our Universe, like the first galaxy formation, detailed atmospheric characterization of potentially habitable exoplanets. The Webb Telescope launched on Christmas Day, a billion dollars over budget and years behind schedule, from the European Space Agency’s launch site in Kourou, French Guiana Space Centre, at 7:20 a.m. EST atop an Ariane 5 rocket (designated Ariane flight VA256). The observatory was coupled to the Ariane 5 launch vehicle by a launch vehicle adaptor ring, which might be utilised by a future spacecraft to grab the observatory in order to correct large deployment issues.
“This is a terrific day, not just for America, our European and Canadian friends, but it’s a great day for planet Earth,” NASA Administrator Bill Nelson said from the Kennedy Space Center after the successful launch. “You guys have really been fantastic and over three decades, you developed this telescope that is now going to take us back in time,” he said of the hundreds of men and women who built and launched the telescope. “It’s a time machine,” he explained, “and it’ll take us back to the very origins of the cosmos.” “We’re going to see extraordinary stuff we’ve never seen before.”
The James Webb Space Telescope has began a nail-biting series of procedures to securely unfurl the observatory’s fragile sunshield, which is now well beyond the moon. The five-layer parasol, which is the size of a tennis court, is necessary to screen out the light and keep Webb’s optics and equipment at minus-370 degrees Fahrenheit. The telescope will only be able to detect feeble infrared light from the first generation of stars and galaxies after that.
The telescope is designed to catch photos of the earliest stars and galaxies to emerge after the Big Bang, light that has been stretched into the infrared spectrum by the expansion of space over the previous 13.8 billion years. The legendary Hubble, which Webb will ultimately replace, cannot see that light. Despite the fact that Hubble was built to investigate visible light wavelengths, it has discovered galaxies that are less than a half billion years old. While it may sound like hyperbole, Nobel Laureate Adam Riess, who used the Hubble Space Telescope to discover the existence of enigmatic dark energy, believes Webb will live up to the hype if it works.
The James Webb Space Telescope’s goals include looking for light from the first star and galaxy that formed after the Big Bang, studying the evolution and formation of galaxies, understanding the formation of planetary systems, stars and the origins of life. JWST might possibly be used to study the declining light of the star (KIC 8462852), which was identified in 2015 and has some unusual light curve characteristics. Observation in the near infrared light, rather than light in visible half of spectrum, is more successful in achieving these aims. As a result, unlike the Hubble Telescope, JWST’s equipment will not measure visible or ultraviolet light, but will have a considerably better capability for infrared astronomy.
The deployment of the sunshade is one of the most dangerous components of the $10 billion project, and it must go off without a hitch or Webb’s research would suffer. On the ground, extraordinary testing were conducted to ensure that the deployment would go as planned, but there are no assurances. “You don’t want to test it too much because the sunshield is so delicate,” NASA project manager Bill Ochs said before launch. “But we did three or four deployments and the final one, we were entirely successful, we felt pretty good about it.” “All it needs to do now is work one more time, and it’ll be in orbit.”
Commands to rotate the first pallet back down on the front side of Webb’s primary mirror were uploaded on Tuesday, three days after the Christmas Day launch and following two perfect trajectory correction thruster firings. Later in the day, the second pallet was successfully moved into place on the aft side of the mirror. Flight controllers will switch their focus to Webb’s primary and secondary mirrors when the sunshade has fully unfurled to finish the post-launch deployment phase.
The telescope’s secondary mirror, which is located at the top of a folded-up tripod assembly, will robotically extend on January 4 to transmit light back down to instruments just below the 21.3-foot-wide primary mirror. The main mirror, which was made up of 18 hexagonal parts, was too big to fit within the Ariane 5’s nose cone. For the launch, six parts, three on each side, were folded back out of the way.
The two wings will be unfurled and sealed in position around Jan. 6 to complete Webb’s main deployments. “I don’t believe we’re over-hyping it if the mission succeeds,” he remarked. “All I can think of is comparing it to Hubble. Even if it’s only half as revolutionary as Hubble, you wouldn’t be exaggerating.”
Webb will arrive at its orbital parking spot a million kilometres from Earth 29 days after launch, on January 23. Before the first science photographs are released, it will take another five months or so to properly align Webb’s mirror segments and check out and verify the telescope’s equipment. Webb should be able to detect light from when the universe was just 200 million years old or thereabouts, extending several hundred million years beyond that. That was the time when the universe first emerged from the hydrogen fog of birth, and starlight began to flow freely through space.
Closer to home, Webb will investigate the atmospheres of planets circling nearby stars to determine their habitability, as well as give routine, up-close views of moons, asteroids, planets, and comets in the Earth’s solar system, from the Mars to the furthest reaches of the Kuiper Belt beyond Neptune. The long-awaited infant photos of the universe are anticipated to provide new insight on the genesis and growth of the galaxies, the black holes at their centres, and the life cycles of the stars, from the birth to the colossal supernova blasts that created most of the elements in the periodic table.
The writer Muhammad Shahid is research scholar at department of Physics at COMSATS University Islamabad. He can be reached at email@example.com