The Cosmic Successor

By: Rivka Reiter  |  May 10, 2018
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See further. See deeper. The journey begins.

That’s how NASA’s trailer for the new James Webb Space Telescope ends. The $8.8 billion telescope is set to replace the Hubble Telescope, almost thirty years after the original launched.

The Hubble Telescope, a school-bus sized space telescope, has been orbiting the Earth since 1990, answering questions about the age of the universe (13.7 billion years!) and seeing as far 13.2 light-years away (pretty darn far).

The new James Webb Space Telescope (JWST) is bigger, better, and colder. After it’s settled at its Lagrange Point 930,000 miles away from the Earth (a point where it can be gravitationally stable, rotating at the same speed as the Earth and taking photos of outer space without being blocked by the Earth or the Sun), it will expand its 300m2 sunshields—basically a giant, tennis court-sized umbrella—to keep it cool. The telescope uses heat-based sensors (infrared tech, like in night vision goggles) to find galaxies, so it needs to be kept as cool as possible. That’s why the sunshield is made of five vacuum-sealed layers, so it keeps the heat from passing from layer to layer, kinda like your portable coffee mug might.

The Hubble has taken incredible photos over the years, and has helped us find some planets in what is called the “Habitable Zone,” planets that are similar enough to Earth that they could possibly host life, even if not ours. Last August, the Hubble found some planets, called Trappist-1, that are within the Habitable Zone. The Pillars of Creation, one of the most iconic of Hubble’s photos, shows stars forming in the Eagle Nebula. Meanwhile, the JWST is going on a search for the universe’s “first light,” to see how galaxies are formed and evolve, to study the birth of stars, and even to learn more about planets light-years away, like their atmospheres and “perhaps even [to] find the building blocks of life.”

All of the pictures of the telescope show this giant golden honeycomb. JWST’s primary mirror is six times larger than Hubble in area. In order to make it aerodynamic enough to launch, the mirror is made up of 18 hexagonal segments, made of gold-coated beryllium, that will unfold after launch. The mirror is what makes it possible for the telescope to see so far, discovering stars that are 400 times fainter than what any other telescope can see. In other words, the faintest star that you can see when you look up at night? Ten billion times fainter than that one.

After the month the JWST spends travelling to the Lagrange Point (that point of stability I mentioned,) tiny explosions will force open the gigantic mirrors. The telescope weighs around 14,000 pounds, about the weight of a school bus, and is going to be as tall as a football field and it’s going to rest on rubber shock absorbing cushions, so that if any space particles hit the telescope or the sun shields, it won’t be knocked off-balance.

Dr. Edward Belbruno, a current math teacher at Yeshiva College, has worked on and off for NASA in the past as a celestial mechanic, a job as cool as it sounds, designing flight projections at the Jet Propulsion Lab in California. “What can go wrong in a spacecraft usually goes wrong,” he said, trying to explain why an unfolding telescope is so complicated, and why so much testing needs to be done. If something really does go wrong out there, the telescope is 1,000,000 miles from Earth and has no way of being fixed. It was designed with a dock, on the off chance that NASA decided to send a team to fix it in the future, but right now the Lagrange Point is too far away for any plans of sending a team to fix it if something doesn’t go according to plan.

The launch is still far away as more and more testing is done on the nearly-finished spacecraft. In December, the mirrors came out of cryo testing—they were cryogenically frozen, like something from a science fiction movie (we’re basically living in one!). They were frozen for 100 days in a thermal vacuum in preparation for the frigid, airless, environment of space, and were tested again and again.

“We don’t even know what 90% of the universe is,” said Dr. Belbruno. The corner of his lip was curled up in a smile; it was obvious that he was thrilled to be talking about the telescope, even while sitting in an empty classroom, squeezed into a tiny desk. He told me about the times he worked with the project manager, Dr. John Mather, on some previous projects. “They have someone in charge who really knows what he’s doing,” Belbruno declared, “They couldn’t have made a better choice.”

As of now, the James Web Space Telescope is set to launch in May 2020 from the French-owned Ariane 51 launch pad, but the launch date has already been pushed back twice, so it may again. NASA and the European Space Agency have been working closely to make this launch successful. In the words of Dr. Belbruno, “This has the potential to revolutionize our understanding of the universe.” To see further. To see deeper. So it’s time to let the journey begin.

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