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World's Largest Space Telescope Is Complete, Expected To Launch In 2018 (space.com)
An anonymous reader quotes a report from Space.com: After more than 20 years of construction, the James Webb Space Telescope (JWST) is complete and, following in-depth testing, the largest-ever space telescope is expected to launch within two years, NASA officials announced today (Nov. 2). NASA Administrator Charles Bolden hosted a news conference to announce the milestone this morning at the agency's Goddard Space Flight Center in Maryland, overlooking the 18 large mirrors that will collect infrared light, sheltered behind a tennis-court-size sun shield. JWST is considered the successor to NASA's iconic Hubble Space Telescope. The telescope will be much more powerful than even Hubble for two main reasons, Mather said at the conference. First, it will be the biggest telescope mirror to fly in space. "You can see this beautiful, gold telescope is seven times the collecting area of the Hubble telescope," Mather said. And second, it is designed to collect infrared light, which Hubble is not very sensitive to. Earth's atmosphere glows in the infrared, so such measurements can't be made from the ground. Hubble emits its own heat, which would obscure infrared readings. JWST will run close to absolute zero in temperature and rest at a point in space called the Lagrange Point 2, which is directly behind Earth from the sun's perspective. That way, Earth can shield the telescope from the sun's infrared emission, and the sun shield can protect the telescope from both bodies' heat. The telescope's infrared view will pierce through obscuring cosmic dust to reveal the universe's first galaxies and spy on newly forming planetary systems. It also will be sensitive enough to analyze the atmospheres of exoplanets that pass in front of their stars, perhaps to search for signs of life, Mather said. The telescope would be able to see a bumblebee a moon's distance away, he added -- both in reflected light and in the body heat the bee emitted. Its mirrors are so smooth that if you stretched the array to the size of the U.S., the hills and valleys of irregularity would be only a few inches high, Mather said.
You can see this beautiful, gold telescope is seven times the collecting area of the Hubble telescope
I guess we need to hope president Trump doesn't decide to melt it down to make a new white house toilet.
Did they double-check the mirror this time? And compensate for zero-G?
The testing is particularly high-stakes, because unlike Hubble, which was repaired and refocused in orbit by astronauts, this telescope is not intended to be repaired by humans.
Yikes. Isn't that sort of like announcing that your vehicle doesn't have seatbelts, so instead you're going to drive very, very carefully? Well, I guess that's not unusual for rocket science.
"Our lessons learned from the Hubble [telescope incident] were, if you really care about something, you've got to measure it at least twice," Mather added. "And if you don't get the same answer, you'd better figure out why."
Maybe they should have talked to a carpenter?
Ok, kidding aside... I really do hope it fares much better than Hubble's initial deployment. There's certainly a lot that can go wrong during development or deployment. But if all goes well, I'm looking forward to seeing what images are captured from the edge of the visible universe.
Irony: Agile development has too much intertia to be abandoned now.
AC, why are you posting on slashdot instead of solving the problems of world hunger or global warming? Hypocrite.
World hunger is a distribution problem. We have enough food for everyone. Unfortunately, our economic system is not able to solve this distribution problem. Maybe we should fix it. Unfortunately, we are not going to do so, as it is not in the interest of those who have.
ESA is going to launch it, seriously.
It's going up on an Ariane V launcher using a French-derived LOX/LH2 engine and Italian solid-rocket boosters with a lot of German sparkly bits to do the control.
Saying "the French" is like saying NASA = "Floridans".
"The telescope would be able to see a bumblebee a moon's distance away..."
If only there were bumblebees in space.
JWST will launch on an Arianne V rocket. That is one of ESA's contributions to the program.
And even if it were to be launched on a "domestic" rocket, it is far, far too late in the program to launch on SpaceX. The choice of launcher gets decided very early on in a program, because the size of the rocket (payload capacity, payload fairing size, flight characteristics, etc.) has to be accounted for during the design of the telescope. By the time they are assembling the telescope, it would be very, very difficult and expensive to switch to a different launcher.
Also, ESA has put a few things at L2 already. Experience counts.
Slashdot still doesnâ(TM)t support Unicode after it was added to the HTML standard in 1997.
Im curious, how does the craft obtain power with its solar pannels? Being in the L2, it will be in earths shadow...
It is not in L2. It orbits it with a 250,000 mile radius orbit, and thus never gets close to the Earth's shadow.
Starships were meant to fly, Hands up and touch the sky - Nicky Minaj