NASA - James Webb Space Telescope - Discussion and Updates

[matthewkantar]

The multitude of things that could go wrong with Webb make it impossible to say if a robotic or human service mission would work. It could be a simple as a stuck element during deployment that just needs a smack with a hammer, or it could be a mission ending snag way down deep inside, making a repair in situ impossible.

NASA will have to wait for it fail or wear out before they can determine if it is fixable.

Matthew

[Blackstar]

BTW, does this thing have reaction wheels?

If so, do they have metal or ceramic ball bearings?

That issue has been fixed.

[vjkane]

BTW, does this thing have reaction wheels?

If so, do they have metal or ceramic ball bearings?

That issue has been fixed.

Apparently going from metallic to ceramic bearings did the trick

[jbenton]

BTW, does this thing have reaction wheels?
...[snip]...
If so, do they have metal or ceramic ball bearings?

That issue has been fixed.

Apparently going from metallic to ceramic bearings did the trick

Which begs the question: does JWST have ceramic bearings?

If so, then this near decade-long launch delay (I have a book written in 2003 that claimed JWST would launch anywhere from 2008-2013...) could be a blessing in disguise: an opportunity to put more modern, more reliable reaction wheels in the thing.

[CuddlyRocket]

The multitude of things that could go wrong with Webb make it impossible to say if a robotic or human service mission would work. It could be a simple as a stuck element during deployment that just needs a smack with a hammer, or it could be a mission ending snag way down deep inside, making a repair in situ impossible.

This thing better work or the fallout will be a wonder to behold ... for outside observers!

[CJ]

One of my concerns regarding the very lengthy delays; how will this impact deployment reliability? The deployment (unfolding) of JWST is very complex, and now the parts, actuators, etc, are far from new. 

[denis]

BTW, does this thing have reaction wheels?

If so, do they have metal or ceramic ball bearings?

That issue has been fixed.

Apparently going from metallic to ceramic bearings did the trick

This video is saying that Ithaco (part of Goodrich ?) changed their wheel bearing design from metallic to ceramic, which seems to have solved the reliability issue they have had on their wheels (premature failure on Kepler, Dawn, FUSE, Hayabusa (?)...).

However, it is irrelevant, as JWST is not using wheels from this supplier.
According to this FAQ, they use wheels from Teldix/RCD (Rockwell Collins Deutschland).
Much better track record than Ithaco....

[Star One]

Both Halves of NASA’s Webb Telescope Successfully Communicate

For the first time, the two halves of NASA’s James Webb Space Telescope — the spacecraft and the telescope—were connected together using temporary ground wiring that enabled them to “speak” to each other like they will in flight.

With all flight components under one roof, technicians and engineers work to prepare the two halves of the JWST.
With all flight components under one roof, technicians and engineers work to prepare the two halves of the James Webb Space Telescope for continued testing and eventual assembly in 2019.

Although it was a significant step forward for the program, this test was an optional "risk reduction" test that took advantage of an opportunity to connect the two halves of the observatory together electrically months earlier than planned.  If any issues had been found, it would have given engineers more time to fix them and without causing further delays.  As a bonus, it also provided a jumpstart for the separate spacecraft and telescope test teams to begin working jointly as they will when the whole observatory is put together in one piece next year.

The James Webb telescope is both an exceedingly complex and rewarding undertaking for NASA and its international partners. Scientists anticipate its findings to rewrite textbooks on astronomy by providing revolutionary observations of the cosmos, while engineers and involved technicians forecast that its challenging design will enable and influence future spacecraft architecture for years to come.

Each piece of Webb has undergone rigorous testing throughout various historic and state of the art facilities across the United States. This ensures the entire observatory is prepared to survive the inherent harshness of a rocket launch to space, and years of continuous exposure to the extremes encountered on a mission nearly a million miles away from Earth.

In February, Webb made an important, and symbolic step forward in its path to completion when all primary flight components of the observatory came to reside under the same roof at Northrop Grumman in Los Angeles, California.  This is where all flight hardware is undergoing final assembly and testing until cleared to launch from the Guiana Space Centre near Kourou in French Guiana.

“What we did now was make electrical connections between the flight telescope and flight spacecraft to understand all the nuances of the electrical interface. Specifically in this test, the spacecraft commanded mirror motion on the telescope, and the telescope replied back with telemetry confirming it. Even though we have tested each half with a simulator of the other half during their parallel construction, there is nothing exactly like connecting the real thing to the real thing. While the sunshield was being reassembled to get back into its environmental testing, we took advantage of the time and did a flight-to-flight electrical dry run right now to reduce schedule risk later,” said Mike Menzel, Webb’s Mission System Engineer.  “The full complement of electrical and software tests will be run next year when the observatory is finally fully assembled for flight.”

The James Webb Space Telescope will be a giant leap forward in our quest to understand the universe and where humans fit in the great cosmic expanse. Webb will examine every phase of cosmic history: from the first luminous glows after the big bang to the formation of galaxies, stars, and planets to the evolution of our own solar system. Allowing for unprecedented scientific observation and discovery worldwide. Webb will broaden and enrich the discoveries achieved by the great space observatories Hubble, Spitzer, and Chandra.

“This test also afforded us an early chance to ensure that the two teams, who had been working separately over the years building and testing the two separate halves of Webb respectively, were able to operate as a single observatory test team. We are enthused that the early communications and commanding risk reduction test has been successfully executed. The procedure was designed and executed by an integrated set of team members from Goddard Space Flight Center, Northrop Grumman, and Ball Aerospace,” said Jeff Kirk, Test Operations Lead.

The James Webb Space Telescope will be the world's premier space science observatory. Webb will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA (European Space Agency) and the Canadian Space Agency.                               

For more information, visit: www.nasa.gov/webb

By Thaddeus Cesari
NASA's Goddard Space Flight Center

[Semmel]

JWST Observer News Roundup:

October-November 2018


*January 6* - American Astronomical Society 233rd Meeting (Seattle, WA)

View All Upcoming JWST Observer Events https://jwst.stsci.edu/events

------------------------------------------------------------------------

  Recent News


    November 29: WebbVR Available for Free Download

https://jwst.stsci.edu/news-events/news/News%20items/webbvr-available-for-free-download

Download WebbVR, a virtual reality experience of the James Webb Space Telescope.


    November 21: JWST Observer Events at the 233rd Meeting of the AAS

https://jwst.stsci.edu/news-events/news/News%20items/jwst-observer-events-at-the-233rd-meeting-of-the-aas

STScI will update the community and provide JWST-related resources at the 233rd meeting of the American Astronomical Society in Seattle, WA.


    November 13: JWST ETC Version 1.3 Has Been Released

https://jwst.stsci.edu/news-events/news/News%20items/jwst-etc-version-13-has-been-released

ETC Version 1.3 includes usability enhancements, accuracy improvements, and new features.


    October 31: The JWST Cycle 1 GO Proposal Schedule: What To Expect

https://jwst.stsci.edu/news-events/news/News%20items/the-jwst-cycle-1-go-proposal-schedule-what-to-expect

What to expect for the JWST Cycle 1 proposal process.


    October 2: New Design for WebbTelescope.org Debuts

https://jwst.stsci.edu/news-events/news/News%20items/new-design-for-webbtelescopeorg-debuts

On October 2, 2018, the Space Telescope Science Institute relaunched WebbTelescope.org with a fresh, new design and updated content.

View All JWST Observer News https://jwst.stsci.edu/news-events/news

This e-newsletter is distributed bi-monthly by the Space Telescope Science Institute. For more information about using the James Webb Space Telescope, visit our website for JWST Observers https://jwst.stsci.edu.

[Star One]

House spending bill fires warning shot at JWST

A new appropriations bill the House plans to vote on next week would provide $21.5 billion for NASA in 2019 but warns that any further problems with the James Webb Space Telescope could lead to its cancellation.

[nicp]

House spending bill fires warning shot at JWST

A new appropriations bill the House plans to vote on next week would provide $21.5 billion for NASA in 2019 but warns that any further problems with the James Webb Space Telescope could lead to its cancellation.

About time they got a warning. I am really looking forward to seeing the science from JWST but the delays on this project are totally ridiculous.

[Targeteer]

https://www.nasa.gov/feature/goddard/2019/nasa-s-webb-is-sound-after-completing-critical-milestones


Feb. 8, 2019
NASA’s Webb Is Sound After Completing Critical Milestones

NASA's James Webb Space Telescope has successfully passed another series of critical testing milestones on its march to the launch pad.

In recent acoustic and sine vibration tests, technicians and engineers exposed Webb’s spacecraft element to brutal dynamic mechanical environmental conditions to ensure it will endure the rigors of a rocket launch to space.
NASA's James Webb Space Telescope has successfully passed another series of critical testing milestones on its march to the launch pad. In recent acoustic and sine vibration tests, technicians and engineers exposed Webb’s spacecraft element to brutal dynamic mechanical environmental conditions to ensure it will endure the rigors of a rocket launch to space.

During liftoff, rockets generate extremely powerful vibrations and energetic sound waves that bounce off the ground and nearby buildings and impact the rocket as it makes its way skyward. Technicians and engineers aim to protect Webb from these intense sound waves and vibrations.

To simulate these conditions, flight components are intentionally punished with a long litany of tests throughout different facilities to identify potential issues on the ground. Webb was bombarded by powerful sound waves from massive speakers and then placed on an electrodynamic vibration table and strongly but precisely shaken. Together, these tests mimic the range of extreme shaking that spacecraft experience while riding a rocket to space.

“Webb’s launch vibration environment is similar to a pretty bumpy commercial airplane flight during turbulence,” said Paul Geithner, deputy project manager – technical, James Webb Space Telescope at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “And, its launch acoustic environment is about 10 times more sound pressure, 100 times more intense and four times louder than a rock concert.”

One half of the Webb observatory, known as the “spacecraft element,” was the subject of this latest testing. The spacecraft element consists of the “bus,” which is the equipment that actually flies the observatory in space, plus the tennis-court-size sunshield that will keep Webb’s sensitive optics and instruments at their required super-cold operating temperature. Northrop Grumman in Redondo Beach, California, NASA’s lead industrial teammate on Webb, designed and built the spacecraft element, and conducted the testing in their facilities with NASA support and guidance. Northrop Grumman and NASA engineers and technicians worked tirelessly together as a team over the last few months to complete these complex dynamic mechanical environmental tests.

The initial attempt at acoustic testing last spring uncovered a problem with a specific portion of sunshield hardware, which required some modifications taking several months. Subsequently, the acoustic test was redone, and this time everything went successfully. With acoustic testing complete, the spacecraft element was transported in a mobile clean room to a separate vibration facility, where its spacecraft hardware was exposed to the bumps and shakes that occur when riding a rocket soaring through the atmosphere at high Mach speeds. Northrop Grumman, NASA and its partner, ESA (European Space Agency), are familiar with the flight profile and performance of the Ariane 5 rocket that will carry Webb into space in early 2021, so technicians tuned the tests to mimic the conditions it’s expected to face during launch.
mobile clean room "clamshell" for JWST

With the successful completion of its mechanical environmental testing, the spacecraft element is being prepared for thermal vacuum testing. This other major environmental test will ensure it functions electrically in the harsh temperatures and vacuum of space. The other half of Webb, which consists of the telescope and science instruments, had completed its own vibration and acoustic testing at Goddard and cryogenic-temperature thermal vacuum testing at NASA’s Johnson Space Center in Houston prior to delivery at Northrop Grumman last year. Once finished with thermal vacuum testing, the spacecraft element will return to the giant clean room where it was assembled, to be deployed from its folded-up launch configuration and into its operational configuration, which will be the final proof that it has passed all of its environmental tests. Then, the two halves of Webb — the spacecraft and the telescope elements — will be integrated into one complete observatory for a final round of testing and evaluation prior to launch.

Webb will be the world's premier space science observatory. It will solve mysteries of our solar system, look beyond to distant worlds around other stars, and probe the mysterious structures and origins of our universe and our place in it. Webb is an international project led by NASA with its partners, ESA and the Canadian Space Agency.

For more information, visit: https://www.nasa.gov/webb

By Thaddeus Cesari
NASA’s Goddard Space Flight Center, Greenbelt, Md.

[catdlr]

NASA’s Webb Is Sound After Completing Critical Milestones

NASA Goddard
Published on Feb 8, 2019

NASA's James Webb Space Telescope has successfully passed another series of critical testing milestones on its march to the launch pad.  In recent acoustic and sine vibration tests, technicians and engineers exposed Webb’s spacecraft element to brutal dynamic mechanical environmental conditions to ensure it will endure the rigors of a rocket launch to space.

Credits:
Michael  P. Menzel: Producer, Writer, videographer, video editor
Thaddeus Cesari: writer

[zincite]

JAMES WEBB SPACE TELESCOPE: Opportunity Nears to Provide Additional Assurance That Project Can Meet New Cost and Schedule Commitments
Publicly Released: Mar 26, 2019.
https://www.gao.gov/products/gao-19-189

What GAO Found
In June 2018, the National Aeronautics and Space Administration (NASA) revised the cost and schedule commitments for the James Webb Space Telescope (JWST) to reflect known technical challenges, as well as provide additional time to address unanticipated challenges. For example, the revised launch readiness date of March 2021 included 5.5 months to address a design issue for the cover of the sunshield (see image). The purpose of the sunshield is to protect the telescope's mirrors and instruments from the sun's heat. NASA found that hardware on the cover came loose during testing in April 2018. The new cost estimate of $9.7 billion is driven by the schedule extension, which requires keeping the contractor's workforce on board longer than expected.

Before the project enters its final phase of integration and test, it must conduct a review to determine if it can launch within its cost and schedule commitments. As part of this review, the project is not required to update its joint cost and schedule confidence level analysis—an analysis that provides the probability the project can meet its cost and schedule commitments—but government and industry cost and schedule experts have found it is a best practice to do so. Such analysis would provide NASA officials with better information to support decisions on allocating resources, especially in light of the project's recent cost and schedule growth.

NASA has taken steps to improve oversight and performance of JWST, and identified the JWST project manager as responsible for monitoring the continued implementation of these changes. Examples of recent changes include increasing on-site presence at the contractor facility and conducting comprehensive audits of design processes. Sustaining focus on these changes through launch will be important if schedule pressures arise later and because of past challenges with communications. GAO will follow up on the project's monitoring of these improvements in future reviews.

What GAO Recommends
GAO recommends NASA update the project's joint cost and schedule confidence level analysis. NASA concurred with the recommendation made in this report.

[matthewkantar]

More of contractors messing up, getting more work as a result. Can this be fixed for future projects?

[ptt]

Hi all, do please go easy, first post and all.  Took me a while to find a decent space forum, hat's off to you all, very good stuff!

So, to JWST.  Brilliant idea, I dearly hope it works perfectly.  But it's just too damn complicated and prone to error IMHO.  I can't help but remember building a guitar out of rubber bands and cardboard boxes when I was a kid, always ended up in flying materials and a loud "twang".  Yes, no sound in space but the chances of that sun shield correctly unfurling and working correctly must be slim.  I do have a simple solution although I suspect it's a bit late.  Have the telescope and shield in two separate sections launched apart then docking after unfurling.  If the first one doesn't work, you can send up a second / third / fourth until one works then dock them and away we go.  Better than this "all or nothing" approach. $100 says that no provision has been made on the device to dock with another.

[theinternetftw]

Welcome to the forum!

Even though it's two years from launch, changing the spacecraft is a non-starter, due to how long it takes to test (and how much every second it's not ready is costing).

Of course, it takes that long because it's a complex collection of the never attempted before, all of which has to work and is not designed to be repaired.  And it costs that much for the very same reason.

There is some solace available in the fact that serviceability is being highly emphasized now for all future such projects.  Everyone seems to understand its lack in JWST was a huge mistake.  As was the "worth it at any cost" budget and the huge laundry list of first-evers.

It'll be interesting to see if a service mission is mounted anyway, if (god forbid) anything adverse happens on deployment.  Humans trucking out to L2 would be a new adventure all its own.

[b0objunior]

Welcome to the forum!

Even though it's two years from launch, changing the spacecraft is a non-starter, due to how long it takes to test (and how much every second it's not ready is costing).

Of course, it takes that long because it's a complex collection of the never attempted before, all of which has to work and is not designed to be repaired.  And it costs that much for the very same reason.

There is some solace available in the fact that serviceability is being highly emphasized now for all future such projects.  Everyone seems to understand its lack in JWST was a huge mistake.  As was the "worth it at any cost" budget and the huge laundry list of first-evers.

It'll be interesting to see if a service mission is mounted anyway, if (god forbid) anything adverse happens on deployment.  Humans trucking out to L2 would be a new adventure all its own.

It sure would be a long way from home!

[Bob Shaw]

The thing needs to be man-tended during the deployment, full stop. - even at L2 This is an ideal opportunity for SpaceX on a Starship demo flight...

[woods170]

The thing needs to be man-tended during the deployment, full stop. - even at L2 This is an ideal opportunity for SpaceX on a Starship demo flight...

Even if someone was watching during deployment there is nothing they could do when deployment goes wrong. This thing was not built to be serviced by astros or robots.