The Electrical Worker online
July 2014


The Telescope That Will See the First Stars
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NASA is betting nearly $8 billion on the skill and competence of nearly 250 members of Baltimore Local 1501, the engineers and technicians working on the James Webb Space Telescope at the Goddard Space Flight Center.

The Webb telescope is one of NASA's largest, most expensive missions ever, the successor to the path-breaking Hubble Telescope. Components for the telescope have been under construction in 27 states and 14 countries for nearly a decade, but in recent months, many of those components have come to Goddard, and assembly for the October 2018 launch has begun.

Using an array of infrared sensors and a mirror nearly six times larger than Hubble's, the Webb telescope is designed to find and study the oldest, farthest, faintest objects in the universe to answer some of the most basic questions about how stars ignited, galaxies formed and planets coalesced out of the echo of the Big Bang.

"Its purpose is to address the deepest questions we have: Where did we come from? Are we alone?" said Amber Straughn, deputy project scientist at Goddard.

But for the telescope's four sensors to see into the early life of the universe, they will need to be cooled to only a few degrees above absolute zero, which is only possible far away from the heat emitted by the sun, the Earth or even the moon. Hubble orbits 375 miles up; the Webb telescope will be sent more than 1 million miles away, four times farther than the moon. So far that if anything goes wrong, if something on the telescope breaks, doesn't line up or unfold correctly, if none of the systems on board can fix it, no rescue or repair mission will be possible.

"We only have one chance to get it right," said Delaney Burkhart, mechanical integration specialist, steward and member of Local 1501's executive board. "Our job is to test, and retest and test again until we are confident that one is all we need."

Between Success and Mission Failure

The IBEW members at Goddard all work in the environmental test and integration facility, the largest building on the wooded campus just outside of Washington, D.C. Most of the buildings look they were dropped in from a run-of-the-mill '60s office park. But from the massive storage tanks to the circular annex with a domed roof, it is very clear that this building is different. Most impressive, rising from the green trees and red brick buildings, is the stark white shell of the facility's heart: the world's largest clean room.

This is Local 1501 member Colette Lepage's world, the space systems development and integration facility, a 12,500 square-foot, nine-story clean room kept 1,000 times cleaner than a hospital operating room. Satellites have to be extremely resilient, strong and flexible at the same time, yet very small things can wreak havoc when satellites are sent where no one can follow. Dust in electronics can cause shorts and atmospheric hydrocarbons and silicone gels found in many kinds of makeup can cause disastrous condensation to form on the mirrors and lenses.

"A smudge on a camera lens is annoying, but dust or condensation on a space telescope can mean mission failure," Lepage said.

Lepage helps design and implement the contamination protocols that are followed by every person in the building throughout testing and integration.

"Every action that involves moving the flight equipment is meticulously planned out and vetted before anything happens," Burkhart says. "We will build specialized tools and support equipment that will only be used once because everything must be in precisely the right place and there are few — if any — replacements for components that will go into space."

And nothing is routine when every part is both irreplaceable and, especially for Webb, unlike anything done before.

The New Hubble

A telescope the size of a school bus, orbiting 375 miles above the earth, Hubble was one of the most extraordinary scientific instruments ever created. But Hubble was in many ways familiar. It shared the simple, tubular design of reflecting telescopes used by everyone from Isaac Newton to amateur astronomers today. The Webb telescope looks like nothing that has ever been built. Instead of a round mirror inside a tube, the James Webb telescope looks like a golden satellite dish flown atop a five-layer kite.

The golden dish is the more than 21-foot diameter mirror and the kite is the tennis-court sized sunshield that will protect the instruments from the heat and light of the sun, Earth and moon.

Both the mirror and the sunshield are far larger than any existing rocket could carry. So instead of a single-piece mirror like Hubble and most ground-based optical telescopes, Webb's mirror is made of 18 gold-plated beryllium hexagonal sections, six of which will tuck away like a bird's wings. The sunshield will be furled like a sail until after separation from the launch capsule, when the telescope will unfold like a butterfly emerging from its cocoon.

Paula Cain and her colleagues in the "blanket shop" handcraft the multilayered thermal insulation that will protect the parts of the telescope that must stay (relatively) warm from the extremes of space and they will isolate the equipment that must stay extremely cold, safe from the heat of the telescope itself.

Like many Local 1501 members, Cain did not originally think about a career in the space program. Her college degree is in fashion design.

"It is not what I pictured, but really there's a lot of overlap," she said. With material that can cost north of $900 a yard, precise and judicious cutting and sewing, all done by hand, is paramount.

"I just tell people I make garments for satellites instead of people," Cain said.

Seeing the Light from the Cold and Dark

Building a mirror so large it must fold up to fit in the launch capsule introduces enormous additional risks and costs, but mission scientists say the calculus was simple: bigger is always better for telescopes. All that extra real estate will allow the scientists to resolve images hundreds of millions of light-years deeper in the universe than Hubble could see.

A light-year is a measure of distance, but it also indicates how long light we see took to reach us. The speed of light is fast, but it isn't infinite. Light from the sun takes nearly eight minutes to reach the Earth, so what we see is not the sun as it is now, but eight minutes before. When Webb picks up images of objects billions of light-years away, it is seeing not only far in the distance, but far in the past.

It is very possible that Webb will record images of the earliest objects that can actually be seen: the first stars to ignite after the universe cooled down from the Big Bang. Future telescopes may well refine the picture and see things we can only imagine, but the last blank spot on the map will be filled in, even if only roughly.

Objects that far and that dim are only perceptible by traces of infrared radiation. Invisible to human eyes, infrared radiation is what we feel on our hands as we hold them up to a campfire. But to feel the tiny bit of heat from a star formed soon after the beginning of the universe, the sensor has to be extremely cold.

One sensor on the Webb, the "middle infrared camera," is designed to analyze the faintest objects in the universe, 10 billion times dimmer than the darkest object the naked eye can see in the night sky. To work, the cold of space at 50 degrees above absolute zero (-370 degrees Fahrenheit) is not nearly cold enough. A liquid helium cooling system will bring it down to a mere 7 degrees above absolute zero (-447 degrees Fahrenheit.)

Marc Sansebastian is designing and building the cooling system's hundreds of small parts, from the gold-plated clamps the size of grains of rice to the cat's cradle suspension system built from wisps of Kevlar thread thinner than a hair.

Sansebastian, who has built components for dozens of satellites since he started at Goddard more than 20 years ago, says he tells people his job is "proudly reducing the mass of the Earth."

The Satellite Torture Chamber

Seeing how the earliest galaxies formed and why there are black holes at their heart … peeling back the fog of time and dust to watch the very first planets coalesce … finding a planet orbiting a distant star with an atmosphere with unmistakable signs of life. This is what is possible with the James Webb telescope if it works.

While many members in the environmental test and integration facility are busy building Webb, the majority try to break it. Local 1501 members run a satellite torture chamber, with a multitude of tools that can zap, cook, freeze and spin satellites and their components. The goal is to replicate the chaos of launch and the extremities of space so that anything that can fail will fail where it can be fixed.

"This is tricky. Deployment cannot possibly be tested in exactly the same conditions it will see in space: zero gravity, cold, vacuum. We don't get that here," said John Mather, the Nobel-Prize winning chief scientist for the telescope. "So we do everything we can here to get as close as possible so we can sleep at night."

For engineering technician Nate Allen, that means mounting components to hydraulic-driven tables that shake and rattle each piece, and then everything together.

"I make sure everything can survive the ride to space," Allen said.

In the acoustic testing lab, speakers like alpine horns, 5 feet high and as long as a car, recreate the sound waves generated by the rocket engines during liftoff.

Technicians in the static test department use hydraulic actuators to push, bend and pull on components. Goddard's enormous centrifuge can accelerate 2-ton payloads up to 30 times the force of gravity.

The most imposing tool in the torturer's dungeon is the five-story space environment simulator. It is a hulking steel globe that looks like a cross between an antique pressure cooker and the spherical submarines that carry marine biologists to the bottom of the ocean's darkest trenches. Local 1501 members lower satellites down into its well and nearly recreate the vacuum and frigid temperatures of space.

"We can't get rid of gravity, but in every other way we can, it's like space in there," Burkhart said.

In late May, the framework housing the four sensors was lowered into the chamber. Massive vacuum pumps remove the air, down to 1 billionth of Earth's normal atmospheric pressure. Then liquid helium less than -420° Fahrenheit is pumped into the chamber. It takes nearly a month for the temperature to stop falling. Then sensors will undergo weeks of testing. Bringing it all back to room temperature and pressure requires another full month.

'All of Us Are Necessary'

Back in the clean room, Lepage said working at Goddard is more than the fulfillment of a dream, because it was even beyond what she imagined.

"I grew up in northern Ontario, sitting out and watching the stars," Lepage said. "I remember when the space shuttles first started flying I wrote down all their names because it felt so important, but also so far away."

The James Webb telescope has many hurdles to clear before the October 2018 launch date. But after years of delays, and questions about its budget, even its future, the telescope is coming together.

Lepage said the project is in some ways like being a member of the IBEW.

"Everything we do here is bigger than anyone of us, but all of us are necessary for it to succeed," she said."

See a video of the James Webb Space Telescope unfolding here:


Members of Baltimore Local 1501 prepare equipment for a test in the space environment simulator at Goddard Space Flight Center.


Local 1501 member Marc Sansebastian


Engineers inspecting one of 18 hexagonal primary mirrors.


The telescope team in front of a full-sized model.


The largest space telescope in history, the Webb telescope will fold up to fit the launch capsule.