Monday July 11, 2011 11:00 am
NASA fighting to keep James Webb telescope alive
NASA's James Webb telescope, the successor to the Hubble, is on the chopping block. With the U.S. Congress arguing over fiscal matters, one of the things that may get cut is NASA's budget, with the expensive James Webb telescope potentially getting the ax. If that happens, a generation of scientific discoveries about the nature of the universe may need to be put on hold.
Right now the future of the Webb telescope, scheduled to launch in 2018, is uncertain. Congress is looking to cut costs, and NASA's budget could be cut by as much as $1.6 billion (or about nine percent of its overall budget). Such a big cut would certainly be the death knell for the Webb telescope, which has so far cost $3 billion but whose final price is expected to hit the $6.8-billion mark.
"The cost overruns are driven by a couple things," says Rick Howard, the program director of the James Webb Space Telescope at NASA. "We've had ten or so technologies that needed to work in order to have this kind of telescope—mirrors actuators, the sunshade. We've made great progress, but it's taken longer and it's been harder than we thought. We've had to invent new adhesives for carbon fiber because what we thought was the right chemical equation didn't work at all. Another source was inadequate early funding of reserves."
Seeing in Infrared
With the Webb in jeopardy, its mission to find out more about the nature of the universe may be postponed. The telescope is fundamentally different from Hubble, scanning the infrared spectrum rather than visual light. Being able to see in infrared is the key to the Webb making new discoveries. For example, it will be able to penetrate dust clouds that are opaque to normal telescopes.
But seeing in infrared is also one of the reasons the Webb is so expensive. Since all objects emit some infrared light, the telescope needs to be positioned much farther from the earth than normal satellites to shield it from potential interference. In fact, the Webb will ultimately be four times further from the earth than the moon. At such a long distance, servicing the telescope will be impossible, says NASA, so it cannot afford any screw-ups or design flaws. As such, testing the Webb's components is extremely detailed.
"We are very concerned about that," says Howard. " There's a huge amount of testing that goes on. We've gone to great lengths to build both sub-scale and full-scale prototypes in order to be able to make sure we fully understand this design. In addition to that we have a lot of testing going on of the flight unit."
What We'll Lose With the Webb
Once it's in place, though, the Webb is quite literally expected to unlock a universe of discoveries. Positioned so far from the Earth and shielded from outside infrared interference, the telescope will be able to see things the Hubble never could. Chief among them: seeing back in time. Since light only travels so fast, the further you look out, the further you look back. The Webb is expected to be able to peer into some of the universe's earliest moments, before even stars existed. This could give insight into how the cosmos came into being.
On top of that, the Webb is going to be looking at how the first galaxies were formed. From observations from Hubble and other telescopes, we know know most galaxies have huge black holes at their centers, but questions remain about how this symbiotic pairing of black holes and stars emerges. The answer likely has to do with "dark matter," the term for the missing matter in the universe that scientists can observe the gravitational effects of, but can't see directly. By looking into the formation of galaxies, the Webb may unlock the secrets of this mysterious substance.
"We'll be looking at the very first stars and galaxies in the universe, which right now are very fuzzy little blobs on the deepest images with Hubble," says Howard. "Not just seeing them, but getting [good] resolution on them. Because it'll be able to look back at the earliest galaxies, it'll be able to see how dark matter has affected light as it travels to us."
Finally, the Webb may help answer the question of whether life exists elsewhere in the universe. The telescope will be able to see better than ever before planets in other star systems and more importantly—which ones have water. A planet with large amounts of water is a prime candidate for life, and the Webb could point us right to them.
"[We'll] be able to look at those planets and look at the spectra, the composition of the atmosphere, the composition of water— it's something only the [James Webb telescope] will be able to do," Howard says. "It'll be able to tell water in the atmosphere, maybe even on the surface."
Looking Back at Hubble
All of its potential discoveries come at a price, however, and it may be one Congress isn't willing to pay. The risk factor is high, too, since the telescope must set itself up perfectly at a vast distance from the earth. If anything goes wrong, it's billions in wasted taxpayer dollars.
In considering the fate of the Webb, it's informative to look back at Hubble, which led to almost two decades of cosmological discovery. Besides finding those galactic black-hole nuclei, Hubble's observations revealed the age of the universe, the repulsive force known as "dark energy," and that planets are common.
"When we launched Hubble, no one thought that it would be able to make the observations and discoveries that it has," Howard says. "Hubble's the only telescope that has ever made an actual observation of a planet orbiting another star. Nobody else has done that. When we launched Hubble, no one had even thought dark energy existed.
"The discovery space is huge for this observatory."
This article, written by Peter Pachal, originally appeared on PCMag.com and is republished on Gear Live with the permission of Ziff Davis, Inc.
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