What's next after Hubble? Earth's eye gets an epic upgrade

Patrick J. Kiger | Special for USA TODAY and National Geographic Channel

Show Caption Hide Caption Building Hubble Video from the National Geographic Channel on Building the Hubble.

As the Hubble Space Telescope marks its 25th year in orbit, its successor is literally taking shape in a large room at NASA's Goddard Space Flight Center in Greenbelt, Maryland. There, engineers clad in white anti-contamination suits, masks and gloves are carefully assembling and testing a telescope that will peer even deeper into space and see light from events that are even closer to the beginning of the universe.

The James Webb Space Telescope, an $8.8 billion U.S.-European-Canadian collaboration that's scheduled to be launched in October 2018, has been designed to go many steps beyond even Hubble's remarkable achievements. Unlike Hubble, Webb won't be parked in a low-Earth orbit, but instead will be placed beyond the moon, 932,000 miles into interplanetary space. That distance will enable Webb to use a solar shield to block out light from the sun, Earth and moon, giving the satellite an even clearer view of faint light from deep space.

Webb also will be equipped with a mirror with about 5.5 times as much surface area as Hubble's, so it can collect much more light. Webb will contain more advanced technology than Hubble, some of which has been developed specifically for it, including ultra-lightweight beryllium optics and detectors that are sensitive enough to record extremely weak signals.

Finally, unlike Hubble, which looks primarily at light frequencies visible to the human eye and shorter ultra­violet wavelengths, Webb will focus on detecting longer waves of infrared light, the sort that are capable of penetrating the clouds of dust that surround stars and planets as they form.

That means that Webb will be able to see distant objects as they existed even earlier in time — 13.5 billion years ago, just 200,000 years after the Big Bang — than what Hubble has been able to view. At that stage of the universe's evolution, the first stars and galaxies were beginning to form.

The analogy used by a NASA website is that if Hubble can view the equivalent of toddlers, Webb will be able to see babies.

By using Webb to compare distant images of early galaxies with the closer, more fully developed ones we've already observed, scientists hope to better understand how galaxies evolve over billions of years.

But that's not all. Webb's enhanced sensitivity will enable it to make better observations of closer objects as well. Astronomers hope to use Webb to learn even more about the atmospheres of extrasolar planets and, as NASA notes, to "perhaps even find the building blocks of life elsewhere in the universe." The Webb telescope will be used to study objects within our solar system as well.

Like Hubble, which took nearly nine years to get into space, Webb has had to survive a tortuous saga to reach its present stage of development. According to a 2014 Washington Post article, Webb's price has skyrocketed since the original $1 billion budget envisioned in the late 1990s, and cost overruns and early delays nearly caused the project's demise in 2011. But after Congress gave the project a second chance, NASA managed to tighten the construction budget.

In some ways, the stakes for Webb are even higher than they were for Hubble, because with Webb, there won't be the option of sending a space shuttle crew to make repairs or upgrades. To avoid the sort of flaw that initially hindered Hubble, Webb's mirror and other components are being subjected to much more rigorous scrutiny from independent testers not involved in the manufacturing. (A slight flaw in the manufacture of Hubble's mirror caused that telescope's first images to be blurry; a shuttle mission installed corrrective optics.)

Like Hubble, Webb will be available for use by thousands of astronomers across the world. And it will no doubt be in similar demand for observations. As Paul Geithner, the project's deputy manager, explained in an online question-and-answer session, "There are a lot of secrets that the universe continues to keep, and the James Webb Space Telescope is the next logical space facility to construct to investigate these mysteries."