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Think about the last time you were cold. As in, teeth-chattering, goosebump-raising, shivering-in-your-boots cold. You were probably outside, and the temperature very well could have been below zero. Washington, D.C.'s lowest recorded temperature is 15 degrees below zero. And in a slightly colder place, such as Alaska, it's more like 80 below.
But if you take that last number -- 80 degrees below zero -- and multiply it by five, you'll get an idea of just how cold the James Webb Space Telescope will be after it's launched a million miles from Earth, in the year 2018.
Introducing Hubble's successor: James Webb
"The whole thing in orbit will be below 40 Kelvin, which is about 400 degrees Fahrenheit below zero," says Ray Lundquist, a systems engineer for the James Webb Space Telescope, at Goddard Space Flight Center in Greenbelt, Md.
The James Webb Space Telescope -- Hubble's successor -- is an international collaboration among NASA, the European Space Agency and the Canadian Space Agency. Goddard is managing the project, named for the NASA administrator who played a crucial role in the Apollo program in the 1960s.
Lundquist spends a lot of time in a special facility at Goddard: the Spacecraft Systems Development and Integration Facility (SSDIF). He frequently works in the clean room, a vast and nearly contaminant-free chamber, where people test and assemble parts of the Webb Telescope.
It's actually the same room where much of Hubble's work was done.
"We just kicked Hubble out of here the last year and year before last, in order to get ready for this program," Lundquist says. Everyone in the clean room must pad around in white booties, with matching jumpsuits and hoods. The whole get-up, says optical engineer Theo Hadjmichael, is affectionately known in the biz as a "bunny suit."
"We're big, white rabbits, gowned from head to toe in a white material that's very, very smooth," he says. "Doesn't allow anything to accumulate."
This is important because particles of schmutz on the Webb Telescope would be like fingerprints on your camera lens, only much worse.
"The particles will distribute because there will be no atmosphere to contain them," Hadjmichael explains. "So a small fingerprint will spread across the optic and contaminate the surface," thereby ruining the images Webb's expected to beam back to Earth. And what glorious images they'll be! Or so says Lee Fineberg, Webb's optical telescope element manager.
"The most rewarding thing about working on a space telescope, and we had this experience when we fixed Hubble, is when those first images come down," Fineberg says. "People have been on this project for 10 years, 15 years, and we're all gonna make it through to the finish line because we want to see those images! You're seeing your baby for the first time!"
"And seeing our own history, out there in the sky," adds Webb's senior project scientist, Nobel Prize winner John Mather. Webb is so powerful, explains Mather that once it's up in space, they'll be able to see the first objects that formed the Big Bang. "The first stars and galaxies," he says. "That's what we're planning to look for. We could even see whether a planet could have water on the surface. So that's how we'll tell if there's a planet that could have life, because it would have water."
And that's where those 400 degrees Fahrenheit below zero come in.
The Webb Telescope works by using mirrors to observe infrared light from distant objects. Infrared is heat radiation, and all warm things - like the sun, the earth, the moon, the telescope itself - emit infrared light. But if you keep the telescope super-cold, then heat can't muddy up the images the telescope is collecting. Mather says that's part of the problem with Hubble.
"The Hubble Telescope glows," he says. "It emits hundreds and thousands of watts of infrared power. And so it can't possibly be used to observe those same wavelengths where it's emitting bright light."
The Webb Telescope, on the other hand, has a five-layered, tennis-court-sized, Kapton sun-shield; Kapton is similar to Mylar, like in a balloon, and using the sun-shield is like slathering yourself in SPF one million. Mather says the sensitivity is so extraordinary, they can see the heat that's emitted by a bumblebee, at the distance of the moon.
And that, says Lee Fineberg, makes the James Webb Space Telescope revolutionary.
James Webb: This generation's Apollo
"I have a lot of friends who remember the Apollo days and they think back to these amazing things NASA did," he says." And what we're doing I think on James Webb is our generation's version of Apollo. We've been to the moon, but we haven't built a telescope that can see the early universe!"
And sure, he says, it's challenging, not to mention costly. Congress has approved $8 billion to launch Webb, and several hundred million more to keep it up in space for the five years required for operation. But Fineberg is certain it's worth it.
"It's part of discovery! It's manifest destiny," he says. "There's just this great desire to understand what we can't see now, and what we haven't been able to see."
Which is enough to warm anyone's heart, he says - even if it takes a whole lot of cold, to do it.
[Music: "Cold Cold Heart" by Tony Bennett from The Essential [Disc 1]]
Photos: Webb Telescope