Engineers covered in sterile white suits, with only their eyes visible, carefully tested and retested parts of the world’s most powerful space telescope in development at Northrop Grumman Corp. in Redondo Beach on Tuesday.
The James Webb Space Telescope, built to be NASA’s successor to the Hubble Space Telescope at a cost of $8.7 billion, will travel 1 million miles beyond Earth’s atmosphere and peer 13.5 billion years into the past.
But, once it leaves Earth, it has to operate perfectly.
As part of ongoing rigorous testing, the telescope’s spacecraft and sun shield have remained in Northrop’s high-bay clean room while the 21-foot-tall, ultra-smooth primary mirror was recently flown to Maryland and Texas for tests.
The mirror is now being subjected to freezing deep-space temperatures in the world’s largest thermal-vacuum test chamber at Johnson Space Center in Houston. The chamber, famously used for testing Apollo mission equipment, was remodeled to accommodate the new telescope.
Preparing for liftoff
When the mirror returns later this year, it will join the spacecraft and sun shield for testing together. They are set to deploy in late 2018.
Workers tasked with readying the one-of-a-kind instrument test its components around the clock to ensure success of its one-and-only mission.
“We go through a massive amount of testing: It’s testing. Then testing the test. Then testing that test,” said Northrop spokeswoman Connie Reese.
“The reason we do all that testing here is that, once it gets to outer space, it’s not serviceable in orbit. We can’t send an astronaut out there. So we’ve got to knock the ball a million miles out of the park that first time.”
The Hubble Space Telescope, in orbit since 1990, has delivered first-ever, vivid images of planetary nebulae, galaxies, planets and other celestial bodies. James Webb, named for the administrator who headed NASA from 1961-68 and was a fierce advocate for space science, is regarded as its successor.
While Hubble orbits about 300 miles from Earth, the James Webb telescope will travel 1 million miles to what’s known as the second Lagrange Point to take photos.
Its mission is to see what happened immediately after the Big Bang roughly 13.7 billion years ago.
“When you get closer to the Big Bang, everything’s dark,” Reese said. “We see formation of the first stars — that first light — about 13.5 billion years ago. That’s why we’re not looking all the way back to the first moment. The infrared will help us see that first light.”
Hubble used vision sight, while this telescope relies on infrared radiation to develop heat-based images.
“This all stems from the scientific mission to detect the earliest life in the universe,” said Jon Arenberg, the telescope’s chief engineer. “To see the very first stars and galaxies at the beginning of time.”
The mission also aims to examine stellar and planetary nurseries, extra-solar planets, and “any object inside our solar system, outside the orbit of Mars,” Arenberg said.
One of the most ground-breaking technological advances made in the development of the James Webb was designing a configuration that would keep the mirror as cold as the space around it to avoid false images. It will remain in temperatures at roughly negative 400 degrees Fahrenheit, which are cold enough to liquify air.
The primary mirror is shielded from the sun’s light by a tennis court-size sun shield. The shield layers thin sheets of Kapton film like “SPF times a million,” Reese said.
The spacecraft that propels the telescope around — and operates as the brains of the system — will remain in a sun-facing compartment, while the sun, moon and Earth will always be hidden from the mirror.
More power, less weight
All the innovations for the telescope are useless if they’re not able to be compactly loaded into a rocket, and light enough to maneuver in orbit with limited propellant.
When the James Webb is launched next year from the coast of South America, it will be folded up on itself so it can fit its 6.5-meter diameter inside an Ariane 5 rocket faring.
“The wings of the mirror will fold up and backward,” Reese said. “The sun shield will fold up like a cocoon. In space, it will unfurl like a transformer.”
The beryllium mirror is made up of 18 hexagonal plates coated in gold. Those sections will fuse together in space into one giant, exceptionally smooth mirror.
“Each of the mirrors can move and will be adjusted after launch,” Arenberg said. “We’re all very excited about this revolutionary mission.”
Canadian and European space agencies are partnering on the mission.
All aspects of the telescope’s development were done from the ground up, including the tooling structures that support it.
“Probably over 1 million people-hours went into the Webb telescope, people who’ve dedicated their lives to this,” Reese said. “They’re excited to contribute to a legacy they can tell their kids and grandkids about. It’s such a diverse talent pool that come together to really make this thing work.”