James Webb Space Telescope (JWST)

[kanarkusmaximus]

Przenieśli JWST w inne miejsce!

[kanarkusmaximus]

Aktualny widok na JWST - pewnie się teraz często przeglądują w tym lustrze.

[Orionid]

Pierwszy testowy pomiar optyczny całego lustra po poddania teleskopu naprężeniom mechanicznym wypadł pomyślnie.

NASA Completes Webb Telescope Center of Curvature Pre-test
Nov. 2, 2016

Taking a “before” optical measurement of the telescope’s deployed mirror is crucial before the telescope goes into several stages of rigorous mechanical testing. These tests will simulate the violent sound and vibration environments the telescope will experience inside its rocket on its way out into space. This environment is one of the most stressful structurally and could alter the shape and alignment of Webb’s primary mirror, which could degrade or, in the worst case, ruin its performance.

Webb has been designed and constructed to withstand its launch environment, but it must be tested to verify that it will indeed survive and not change in any unexpected way. Making the same optical measurements both before and after simulated launch environment testing and comparing the results is fundamental to Webb’s development, assuring that it will work in space.

“This is the only test of the entire mirror where we can use the same equipment during a before and after test,” said Ritva Keski-Kuha, the test lead and NASA’s Deputy Telescope Manager for Webb at NASA's Goddard Space Flight Center in Greenbelt, Maryland. “This test will show if there are any changes or damages to the optical system.” (...)

http://www.nasa.gov/feature/goddard/2016/nasa-completes-webb-telescope-center-of-curvature-pre-test/
http://www.nasa.gov/image-feature/james-webb-space-telescope-mirrors-will-piece-together-cosmic-puzzles
http://www.space24.pl/485562,zakonczono-budowe-kosmicznego-teleskopu-jamesa-webba

[Orionid]

Ostatnia z warstw osłony termicznej JWST  została zamontowana 29 września 2016.

Final Sunshield Layer Completed for NASA’s James Webb Space Telescope
Oct. 31, 2016

Designed by Northrop Grumman in Redondo Beach, California, the Webb telescope’s sunshield will prevent the background heat from the sun from interfering with the telescope’s infrared sensors. The five sunshield membrane layers, designed and manufactured by the NeXolve Corporation in Huntsville, Alabama, are each as thin as a human hair. The layers work together to reduce the temperatures between the hot and cold sides of the observatory by approximately 570 degrees Fahrenheit. Each successive layer of the sunshield, made of kapton, is cooler than the one below. The fifth and final layer was delivered on Sept. 29, 2016 to Northrop Grumman Corporation’s Space Park facility in Redondo Beach. (...)

http://www.nasa.gov/feature/goddard/2016/final-sunshield-layer-completed-for-nasa-s-james-webb-space-telescope

[astropl]

No i masz ci los:

Vibration Test Status
Updated Dec 16, 2016 (originally posted Dec 7, 2016)

The James Webb Space Telescope is undergoing testing to make sure the spacecraft withstands the harsh conditions of launch, and to find and remedy all possible concerns before it is launched from French Guiana in 2018. During the vibration testing on December 3, at Goddard Space Flight Center in Greenbelt, Maryland, accelerometers attached to the telescope detected anomalous readings during a particular test. Further tests to identify the source of the anomaly are underway. 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. We will provide updates as they are available.

Źródło.

[Szaniu]

Coż.. lepiej niech wszelkie anomalie wyjdą póki JWST jest na Ziemi . Na L2 ratunku nie będzie .

[astropl]

Coż.. lepiej niech wszelkie anomalie wyjdą póki JWST jest na Ziemi . Na L2 ratunku nie będzie .

Jak to, a Orion?

[velo]

Albo od razu ratunek z grubej rury statkiem Federatsija!

[Orionid]

Webb nie  wykazuje uszkodzeń po teście wibracyjnym.
Wznowienie tych testów planowane jest na styczeń.
Przewidziano rezerwy czasowe wynikające z  ewentualnych problemów.

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 website, 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.”

http://spacenews.com/no-damage-to-jwst-after-vibration-test-anomaly/

Wykryto anomalie w odczytach podczas testów James Webb Space Telescope
PRZEZ JULIA WAJORAS W DNIU 29 GRUDNIA 2016

(...) 23 grudnia NASA wydała drugie oświadczenie, potwierdzając że do żadnego uszkodzenia teleskopu nie doszło.
Inżynierowie przeprowadzili też “mniej intensywne testy wibracyjne sprzętu, by zmierzyć jego odpowiedź i porównać z odczytami sprzed anomalii”, oświadczyła NASA. Testom poddano moduł OTIS, w którego skład wchodzą lustra optyczne i oprzyrządowanie naukowe zawierające cztery główne instrumenty teleskopu.(...)

Źródło: http://kosmonauta.net/2016/12/wykryto-anomalie-w-odczytach-podczas-testow-james-webb-space-telescope/

[Orionid]

Testy wibracyjne zostały wznowione po zdiagnozowaniu przyczyn wykrytych wcześniej anomalii.
Powodem ponadnormatywnych drgań były bardzo małe ruchy mechanizmów zabezpieczających lustra teleskopu podczas startu.
Potrzebne były zmiany w profilu testowym, by wyeliminować to zjawisko.
Dodano testy  diagnostyczne pozwalające stwierdzić w jaki sposób testy naziemne są  bardziej obciążające od tych występujących  podczas startu.

NASA Restarts Rigorous Vibration Testing on the James Webb Space Telescope
Jan. 25, 2017

On December 3, 2016, vibration testing automatically shut down early due to some sensor readings that exceeded predicted levels. After a thorough investigation, the James Webb Space Telescope team at NASA Goddard determined that the cause was extremely small motions of the numerous tie-downs or “launch restraint mechanisms” that keep one of the telescope’s mirror wings folded-up for launch.

“In-depth analysis of the test sensor data and detailed computer simulations confirmed that the input vibration was strong enough and the resonance of the telescope high enough at specific vibration frequencies to generate these tiny motions. Now that we understand how it happened, we have implemented changes to the test profile to prevent it from happening again,” said Lee Feinberg, an engineer and James Webb Space Telescope Optical Telescope Element Manager at Goddard. “We have learned valuable lessons that will be applied to the final pre-launch tests of Webb at the observatory level once it is fully assembled in 2018. Fortunately, by learning these lessons early, we’ve been able to add diagnostic tests that let us show how the ground vibration test itself is more severe than the launch vibration environment in a way that can give us confidence that the launch itself will be fully successful.”

The team resumed testing last week picking up where they left off in December.  The test was successfully completed. Now that vibration testing along this one direction or “axis” is finished, the team is now moving forward with shaking the telescope in the other two directions to show that it can withstand vibrations in all three dimensions.

“This was a great team effort between the NASA Goddard team, Northrop Grumman, Orbital ATK, Ball Aerospace, the European Space Agency, and Arianespace,­­” Feinberg said. “We can now proceed with the rest of the planned tests of the telescope and instruments.”

https://www.nasa.gov/feature/goddard/2017/nasa-restarts-rigorous-vibration-testing-on-the-james-webb-space-telescope

Zdjęcie: NASA engineers and technicians position the James Webb Space Telescope (inside a large tent) onto the shaker table used for vibration testing.
Credits: NASA/Chris Gunn

[Orionid]

O poddawaniu teleskopu specjalnym działaniom wibracyjnym na "shaker table".

Because of the sheer size and scale of the assembled Webb telescope, some of the equipment typically used to test spacecraft simply doesn’t measure up. One of those is a "shaker table" that is used to shake satellites to ensure a spacecraft like Webb can withstand the shaking that comes with a ride into space on a rocket.

So, engineers at Team Corporation in Burlington, Washington built a new, large and advanced shaker table system at NASA's Goddard Space Flight Center in Greenbelt, Maryland, especially for testing Webb. "The new “Vibration Test Systems” simulates the forces the telescope will feel during the launch by vibrating it from 5 to 100 times per second" said Jon Lawrence, Webb telescope mechanical systems lead and launch vehicle liaison at NASA's Goddard Space Flight Center.

For Webb, the need for a new shaker system was a combination of things, including shaker force magnitude, the shaker table’s ability to handle the telescope’s highly offset center of gravity, and the need for a precision “smart” shaker control system—one that will automatically adjust shaker input levels based on test article responses, including an automatic ‘soft shutdown’ capability.  "No matter what facility anomaly might be experienced during testing (loss of power, loss of coolant, etc.), the Vibration Test System or VTS is designed to shut down 'softly' so as to avoid imparting potentially damaging loads," Lawrence said. After vibration testing of the telescope is completed soon, the new VTS can be used to test other future large spacecraft. 

To make sure it works properly before using it to test the flight telescope, engineers put the new shaker system though its paces with many practice runs over months, using a dummy mass to represent the telescope.  In November, Webb was moved from the Spacecraft Systems Development and Integration Facility ‘cleanroom’ and onto the new neighboring Vibration Test System (VTS), where testing is ongoing.  While in the shirtsleeve environment of the VTS, a large 3-story tall cover enshrouds the telescope, acting as a portable ‘cleanroom’ that protects it from dust and dirt.


Link do materiału:

https://phys.org/news/2017-02-nasa-webb-telescope-shakedown.html
dublet: https://www.nasa.gov/feature/goddard/2017/nasa-gives-the-webb-telescope-a-shakedown

[Orionid]

Trochę odpowiedzi na pytania dotyczące JWST
https://jwst.nasa.gov/faq.html#howlong

[ekoplaneta]

Ja jestem ciekawy jak będą wyglądały planety i odwiedzone przez sondy kosmiczne planety karłowate naszego Układu Słonecznego? Czy jest gdzieś grafika przedstawiająca możliwy do uzyskania przez JWST obraz tych ciał?

[Orionid]

Teleskop w komorze akustycznej i poza nią.

Inside NASA's Goddard Space Flight Center in Greenbelt, Maryland the James Webb Space Telescope team completed the environmental portion of vibration testing and prepared for the acoustic test on the telescope. Engineers and technicians pushed the telescope (wrapped in a clean tent) through a large set of insulated steel doors nearly a foot thick into the Acoustic Test Chamber, where the telescope will be exposed to the earsplitting noise (and resulting vibration) of launch. These photos show the telescope inside (top) and outside (bottom) the acoustics chamber.

https://www.nasa.gov/feature/goddard/2017/nasas-webb-telescope-team-prepares-for-earsplitting-acoustic-test
dublet: https://phys.org/news/2017-02-nasa-webb-telescope-team-earsplitting.html
https://www.eurekalert.org/multimedia/pub/134146.php

[Orionid]

I po testach akustycznych i wibracyjnych

For the acoustic test, the telescope was wrapped in a clean tent, and engineers and technicians pushed it through a large pair of insulated steel doors nearly a foot thick into the Acoustic Test Chamber. In the chamber the telescope was exposed to the earsplitting noise and resulting vibration of launch.

A new vibration test system also known as a shaker table, was built specifically for testing the Webb. The Webb was mounted on the shaker table and experienced the simulated forces the telescope will feel during the launch by vibrating it from 5 to 100 times per second. The test ensures a spacecraft like Webb can withstand the vibrations that occur as a result of the ride into space on a rocket.

https://www.nasa.gov/feature/goddard/2017/nasas-james-webb-space-telescope-completes-acoustic-and-vibration-tests