james webb space telescope golden mirror person nasa gsfc

NASA's Goddard Space Flight Center

 

 

 

NASA on Wednesday announced a huge milestone in its $8.7 billion James Webb Space Telescope mission: the completion of the observatory's gigantic golden mirror.
 
 

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To commemorate the moment, the space agency's Goddard Space Flight Center released a dramatic video about the telescope on YouTube.

"The efforts of thousands of people across the United States, Canada, and Europe, for almost two decades achieved this milestone," the narrator said. "Getting to this point wasn't easy. ... Before astrophysicists' dreams of building Webb could be realized, 10 technologies that did not exist needed to be created and perfected. They were."

The video shows off many of those revolutionary technologies, including lightweight support structures, sensors, and more.

But we noticed that a crucial part of the telescope — about a minute and 30 seconds into the video — is blurred out beyond recognition:

 

 

In case that's hard to see, here's a labeled screenshot:

jwst blurred mirror segment labeled

NASA's Goddard Space Flight Center; Business Insider

 

 

And let's zoom in on that a bit:

jwst blurred mirror segment labeled

NASA's Goddard Space Flight Center; Business Insider

 

 

We provided the first image to Lynn Chandler, a NASA representative for JWST, and asked why the part circled in red was blurred out.

"This technology is proprietary. The government must respect the intellectual property of its industry partners," Chandler told Business Insider in an email.

We then asked which company made the blurred-out part, and requested more details about it and its role in JWST's mission — which, by the way, is to study objects at the edge of the universe and quite possibly the air around Earth-like exoplanets.

"That is the secondary mirror support structure with the secondary mirror on it, which includes details of mirror mounts," Chandler said. "The secondary mirror relays light from the primary mirror and does optical correction."

For reference, below is JWST's secondary mirror with its convex, gold-plated surface. It's a critical part. It takes all of the giant primary mirror's light and focuses it onto a third mirror inside the telescope's housing, which then bounces it into a suite of detectors. Presto, images of the universe.

The blurred-out part on the backside, which you can't see, is noted by the arrow:

jwst secondary mirror nasa labeledNASA/Chris Gunn

 

 

NASA declined to tell us which company made the blurred-out part, saying that information is an International Traffic in Arms Regulations issue. (More on this jargon in a moment.)

However, we know Northrop Grumman is the prime contractor that designed the spacecraft, and Ball Aerospace built the secondary mirror.

Lon Rains, a Northrop Grumman representative, declined to comment further and asked us to direct our questions to NASA. Ball Aerospace did not immediately respond.

Wait: Why is a mirror considered a weapon?

james webb space telescope mirror reflection nasa

NASA

 

Why is the back of a mirror on a taxpayer-funded scientific observatory considered an "arm" that must be regulated?

 

Probably because of spy satellites.

After all, if your telescope can see as sharply as Hubble, yet resolve objects 10 to 100 times dimmer — as JWST should be able to do — that could be useful for peering down at human activity on Earth. And the US government wants to maintain any edge it can over the militaries of countries like China and Russia.

In fact, if you're working in the US — or for the country — on anything that could be even remotely considered a weapon, including a do-it-yourself spacesuit, you have to make sure it's not on the Department of State's ITAR munitions list. Otherwise you might have to pay up to $1,094,010 and possibly face jail time for each violation.

ITAR experts are common inside companies and agencies that work with space technologies, so one of them at NASA probably reviewed their video and said "this part has to be blurred out" to avoid a violation.

"It's basically caution about space hardware details being released by the US government," Anand Sivaramakrishnan, an astronomer at the Space Telescope Science Institute in Baltimore, Maryland (which works closely with the JWST mission), told Business Insider.

"If I had a piece of space hardware in my room, I may not be allowed to have a foreigner come into my room" per ITAR regulations, Sivaramakrishnan said. "I couldn't let him or her touch it."

What isn't being shown?

james webb space telescope golden mirror complete nasa gsfc

NASA's Goddard Space Flight Center

 

Though we're not in the aerospace business, we don't want to violate ITAR — and possibly pay a million dollars.

 

But we can describe what's back there, generally speaking. (Note: There is a moment in the NASA video that does appear to show the back of the secondary mirror.)

So what is it?

Sivaramakrishnan said it's probably the support structure for the mirror, plus a cluster of motorized actuators that can move it.

You're already familiar with mirror actuators if you've driven a modern car. They're what whir when you fiddle with a side-mirror adjustment knob. But where automobile actuators typically have only two actuators and degrees of freedom — side to side, and up and down — each of JWST's mirrors has six degrees of freedom.

Sivaramakrishnan said the cluster of six actuators is called a hexapod.

"If you take a computer keyboard and hold it in space, it needs six numbers to describe where it is in space," he said. That's up and down, forward and backward, side to side, and a rotational aspect to each one. "So if you want to put a mirror in the exact right location, you have to specify that. And that's a hexapod."

The precision you need in a space telescope in mind-bogglingly precise, though. And JWST has 19 gold-plated mirrors with a hexapod a piece.

Sivaramakrishnan said the tolerance — or error in distance — that the primary mirror of JWST can only be off by 140 nanometers, or just larger than the width of an HIV virus. Any more, and there could be huge problems with the focus and exposure.

The hardware required to do this on JWST is "fancy," he said, and "the details are under restriction."

So if you'd like to find out more, now is as good a time as any to work toward your aerospace engineering degree and get a job at NASA or one of its contractors. Good luck!

Quelle: Bussines Insider Deutschland

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Update: 28.11.2016

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Some Assembly Required: New Space Telescope Will Take Shape After Launch

 
 

The huge sun shield of NASA's James Webb Space Telescope must be carefully folded to fit into a space about the size of a school bus before takeoff.

Chris Gunn/NASA

The next generation of great space telescopes is heading into its final round of ground tests. The nearly $9 billion James Webb Space Telescope will replace the aging Hubble Space Telescope. It's designed to provide unprecedented images of the earliest stars and galaxies that formed in the universe.

But before the telescope can get to work, there are still a lot of engineering challenges to overcome.

For example, the Webb telescope is designed to look at the infrared wavelengths of light given off by stars. Infrared is needed to see some of the earliest stars and galaxies that formed billions of years ago.

But to work properly, infrared telescopes have to be kept cold — very cold. So engineers had to design a multilayered sun shield to protect the telescope from the sun's heat.

"That's like a big umbrella — beach umbrella — so, we keep that facing the sun and the Earth so it dissipates all the heat through all the layers," says Begoña Vila, an astrophysicist and systems engineer at NASA's Goddard Space Flight Center, in Greenbelt, Md. "That allows all the instruments to cool to the temperatures that we need."

Now, the sun shield is big, about the size of a tennis court, and for launch it has to fit into a much smaller space — about the size of a school bus. So engineers had to come up with a way to fold it up. They also had to design a way to fold up the main mirror, and several other critical instruments.

 

An artist's rendering of the James Webb Space Telescope. The telescope's silver, umbrella-shape heat shield will be the size of a tennis court, engineers say. It's crucial to keep cool the instruments that detect infrared light from distant stars.

Northrop Grumman/NASA

Then, after launch, everything has to unfold in a carefully choreographed sequence of steps over two weeks. You can see that sequence in this video.

Many of the steps are absolutely crucial. A failure would compromise the telescope's functionality and could render it useless. For the army of scientists and engineers who have been working on the telescope for nearly two decades, the deployment phase will be nerve-wracking.

"Yes, I think that scares all of us," says Vila. But there's no way around it. "We do as much testing as we can."

The Webb telescope has had a difficult history. It is over budget and behind schedule, and Congress nearly killed the project earlier in the decade. The telescope is scheduled to launch in October 2018. We should know later that year whether the engineering challenges were successfully cleared.

Quelle: npr

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Update: 30.11.2016

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NASA's Webb Telescope Clean Room 'Transporter'

Webb Telescope in clean room with tent being lowered over mirrors

What looks like a teleporter from science fiction being draped over NASA's James Webb Space Telescope, is actually a "clean tent." The clean tent protects Webb from dust and dirt when engineers at NASA's Goddard Space Flight Center in Greenbelt, Maryland transport the next generation space telescope out of the relatively dust-free cleanroom and into the shirtsleeve environment of the vibration and acoustics testing areas. In two years, a rocket will be the transporter that carries the Webb into space so it can orbit one million miles from Earth and peer back over 13.5 billion years to see the first stars and galaxies forming out of the darkness of the early universe.

Quelle: NASA

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Update: 21.12.2016

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Engineers detect anomaly during testing of James Webb Space Telescope

An unknown problem occurred during vibration tests to simulate launch conditions.

It's never a good thing when an anomaly is detected in your scientific instrument during pre-operational testing. When that instrument is the James Webb Space Telescope—which is expected to cost about $8.8 billion, cannot be fixed after launch, and is counted upon to provide insights about the earliest days of the Universe—it's cause for significant concern.

The anomaly occurred earlier this month, on December 3, during vibration testing at Goddard Space Flight Center in Maryland. As part of the run-up to a launch in late 2018, the telescope will be subjected to all manner of conditions, from extreme temperatures to a hard vacuum, to ensure that it will survive during its five- to 10-year mission in deep space. The telescope must also withstand its launch aboard an Ariane 5 rocket, and the vibration test mimicked the shaking and gravitational forces of launch. After the test began, accelerometers detected "anomalous readings," but so far the cause of the anomaly has yet to be determined.

"Further tests to identify the source of the anomaly are underway," the agency stated in an update. "The engineering team investigating the vibe anomaly has made numerous detailed visual inspections of the Webb telescope and has found no visible signs of damage. They are continuing their analysis of accelerometer data to better determine the source of the anomaly. They have conducted a low-level vibration of the hardware to measure its responses, and are comparing the results with data obtained prior to the anomaly. Engineers are currently running diagnostics to determine the cause and to assess any potential impacts."

The oldest and most distant objects in the Universe are moving away from Earth the fastest, so they have the largest red shift, best viewed in the infrared spectrum. The Webb telescope will specialize in the infrared and, therefore, should capture images of the Universe's first stars and galaxies, which formed only 200 million years after the Big Bang.

This telescope is vitally important to the astronomy community because of its unique capabilities for a space-based telescope and also because Webb has cost so much it has had a deleterious effect on other parts of NASA's science budget. It is too big to fail.

Quelle: ars TECHNICA

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Update: 24.12.2016

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No damage to JWST after vibration test anomaly

 

SANTA FE, N.M. — NASA’s James Webb Space Telescope shows no signs of damage after an “anomaly” during a vibration test earlier in the month, the agency announced Dec. 23.

In a statement posted on the JWST web site, NASA said that engineers were making progress tracking down the root cause of the Dec. 3 incident that halted vibration testing of the telescope’s mirror assembly and instruments, known as the Optical Telescope element and Integrated Science (OTIS).

“All visual and ultrasonic examinations of the [telescope] structure continue to show it to be sound,” NASA said in the update. “Currently, the team is continuing their analyses with the goal of having a review of their findings, conclusions and plans for resuming vibration testing in January.”

The OTIS assembly, which includes the telescope’s 6.5-meter segmented primary mirror, secondary mirror and associated structures, and its suite of four science instruments, were undergoing vibration testing at the Goddard Space Flight Center Dec. 3 when engineers detected “anomalous readings” from accelerometers attached to the telescope. NASA halted the vibration tests to study the data as well as inspect the telescope for any damage.

NASA has not provided additional details on the nature of the vibration anomaly. The agency said in its latest update that, since the anomaly, the spacecraft team “successfully conducted two low level vibrations of the telescope.”

The vibration tests, as well as planned acoustic tests, are designed to simulate the environment JWST will experience during its launch on an Ariane 5 in late 2018. “We are about to subject this beautiful beast, which is finished, to see if it will survive launch,” said John Mather, the JWST senior project scientist, at a Nov. 2 media event at Goddard about the telescope. “We expect it to, but we still have to prove it.”

It’s unclear that effect the delay in the vibration and acoustic testing will have on JWST’s schedule. At the November event, Bill Ochs, NASA JWST project manager, said plans then called for shipping OTIS in February to the Johnson Space Center, where it will undergo thermal vacuum tests in a refurbished Apollo-era chamber there. It would then go in mid-2017 to a Northrop Grumman facility in Southern California to be integrated with the spacecraft bus and sunshield, and then undergo further testing before shipping to the French Guiana launch site in mid-2018.

However, project officials have emphasized that JWST has healthy schedule reserves put into place after a “replan” of the project in 2011, when cost and schedule overruns threatened JWST with cancellation. Those reserves are intended to mitigate any effect on the mission’s overall schedule from testing delays.

The replan provided JWST more schedule margin than required for a typical NASA project “because it’s Webb and we knew there would be additional complications,” said Scott Willoughby, Northrop Grumman vice president and program manager for JWST, in an interview at the Nov. 2 NASA event. “We’re right in line to where we need to be at this point in time, with two years to go before launch.”

Quelle: SN