Earlier this month NASA introduced that on December 18, after years of delays, the James Webb Space Telescope will lastly depart Earth on a mission to revolutionize astrophysics and cosmology.
But earlier than this $10-billion observatory can start its work, it should survive a frightening commute that features a voyage at sea, a rocket launch and a 1.5-million-kilometer flight to its vacation spot: Lagrange Point 2, or L2. Far past the orbit of the moon (and out of attain of any near-term rescue mission), L2 is a area the place the gravitational tugs of Earth and the solar steadiness out to create an ideal long-term parking place for telescopes. As Webb leaves our planet and moon behind, it should additionally deploy key elements that had been folded as much as match inside its rocket. This high-tension course of entails some 178 launch mechanisms, every of which should function flawlessly for the telescope to finish its 40 or so main deployments.
“This is the most complex scientific mission that we’ve done,” says Nancy Levenson, deputy director of the Space Telescope Science Institute (STSci). “There’s a lot that has to go right.”
Webb is with out query probably the most superior house telescope ever constructed. The spacecraft’s infrared gaze will penetrate cosmic clouds of mud to disclose the hidden particulars of stellar nurseries and embryonic protoplanets halfway by way of formation. It may also collect the faint photons effused by the primary stars and galaxies to kind after the massive bang—which had been initially emitted as seen mild however have since been stretched, or “redshifted,” by the growth of the cosmos.
“It’s going to help us unlock some of the mysteries of our universe,” says Greg Robinson, Webb’s program director at NASA. “I want to say it’s going to rewrite the physics books.”
But that assumes all goes in keeping with plan.
By Land and Sea
Webb’s journey will start in Redondo Beach, Calif., on the Northrop Grumman facility the place its development and remaining exams had been accomplished. There the spacecraft, which is at the moment folded up, shall be positioned right into a specialised delivery container referred to as the Super Space Telescope Transporter for Air, Road and Sea, or Super STTARS. The customized journey pod will defend Webb from humidity, vibrations and fluctuating temperatures.
Later this month, whereas housed inside its high-tech cocoon, Webb shall be transported to the town’s harbor and positioned on a ship. The actual date of departure has been saved beneath wraps to stifle piracy, says Massimo Stiavelli, head of Webb’s mission workplace at STScI.
Details concerning the safety accompanying the telescope haven’t been made public. Even so, Stiavelli says that he’s unconcerned about pirates stealing the dear cargo, due to quite a few undisclosed however very actual safety measures put in place for the maritime journey. In the occasion of a high-seas heist try, he says, “I would worry about [the safety of] the pirates themselves.”
After departing from shore, the telescope, nonetheless contained in Super STTARS, will voyage south alongside the coast and thru the Panama Canal. Webb will probably enter the Caribbean someday in early October—that’s, throughout hurricane season.
Safe harbors have been recognized all alongside the spacecraft’s delivery route. And climate circumstances shall be monitored intently to make sure that it doesn’t unexpectedly discover itself caught susceptible in a storm, Stiavelli says.
After about two weeks at sea, the telescope will arrive on the port and European Space Agency (ESA) launch website of Kourou, French Guiana. There Webb will bear launch preparations, which embody fueling it, performing remaining electronics checks and, after all, mounting the spacecraft on its celestial steed: ESA’s Ariane 5 rocket.
Still folded, the 6,500-kilogram telescope shall be secured inside the highest of the rocket, inside a chamber referred to as the fairing. Once positioned, Webb shall be able to take to the skies.
Presuming no additional delays in its path to the launchpad, early within the morning of December 18, Webb will blast off with a slight eastward trajectory over the Atlantic Ocean. Its Ariane 5 rocket is taken into account a dependable workhorse, and the telescope itself has handed exams meant to imitate the stresses of a launch, so confidence is excessive that the journey to orbit will go easily, Robinson says.
Still, “one of the largest sighs of relief will be a successful launch,” says Heidi Hammel, a vice chairman on the Association of Universities for Research in Astronomy. “As we say in the business, this is rocket science. We’re putting this incredibly precious resource on top of a rocket and setting the fuse, so to speak.”
The Bloom of Webb
Once it’s about 10,400 kilometers into its journey, Webb will detach from the Ariane 5’s second stage, signifying the top of the launch. Nevertheless, probably the most nerve-racking a part of Webb’s journey may have solely simply begun: a 1.5-million-kilometer cruise to L2, throughout which the folded telescope will slowly start to unfurl.
“That’s when the nail biting starts,” Hammel says. “We aren’t there. We can’t make adjustments, so things must work well.”
Just moments after separating from its rocket, Webb’s solar-power array will unfold to start supplying electrical energy to the spacecraft. Although the solar-array deployment is a comparatively easy process, its success is essential to energy all following operations, Stiavelli says.
About 12 hours after launch, the craft’s thrusters will hearth for the primary time to right its trajectory. Course corrections should be environment friendly to protect the telescope’s gas and maximize its life span, Stiavelli says. Confirmation of a profitable course correction won’t arrive till effectively after the very fact, though subsequent tweaks to Webb’s flight trajectory could be made if wanted.
As the telescope nears its third day in house, Webb will start to deploy one in all its most intricate and outstanding devices: the sunshield. If unspooled with no hitch, a stack of 5 huge kite-shaped sheets of polyimide movie will block daylight and warmth from reaching the telescope’s infrared sensors, which should stay at extraordinarily low cryogenic temperatures to operate correctly.
The sunshield is essential for protecting the telescope sufficiently chilly in order that it will possibly sense the infrared glow of cosmic daybreak, Hammel says. “The deployment has got to go well,” she provides.
But to open the sunshield, round 150 launch mechanisms should hearth appropriately over the course of three days. The sophisticated deployment entails round 7,000 elements, together with 400 pulleys, eight motors and 140 launch actuators. The sunshield’s deployment is essential to reaching scientists’ wildest goals for the observatory. But for aerospace engineers, the process’s complexity and excessive variety of single-point failures are the stuff of nightmares.
“It’s a big task: getting these five extremely thin layers that are each the size of a tennis court all stretched out and separated from each other,” Hammel says. And the nervousness won’t fade with a nominal sunshield deployment. Six days into the flight, the telescope’s secondary mirror, positioned on the finish of three lengthy arms, will decrease into place. Despite its title, the secondary mirror is a essential part for Webb’s success, Hammel says. If different deployments don’t work out completely, there could also be work-arounds. “But if the secondary mirror doesn’t deploy successfully, we have no telescope,” she says. “We got nothing.”
On the seventh day Webb’s 6.5-meter main mirror, a set of 18 beryllium-hewn, gold-plated hexagonal segments, will start to unfurl. First, two “wings” will swing out and lock into place like items of a folding desk. Then tiny actuators will push or pull every of the mirror segments right into a micron-precise alignment, producing the first mirror’s singular focus. Deploying and aligning the first mirror will contain 132 actuators and motors, every of which should operate correctly.
Finally, a month after launch, Webb ought to attain L2, concluding one of the crucial audacious spaceflights ever tried and permitting the world’s astronomers to collectively exhale.
“We’ve been practicing for this for years,” Hammel says. “This is like an orchestra concert with hundreds of people all playing different instruments. Everybody has to have practiced their part and all the instruments have to be ready. And then we play the music.”