James Webb Space Telescope (Technical Post ONLY !)

NMaude

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Here's another progress video on the JWST phasing its' primary-mirror segments:


Edit: Here's another short video detailing the progress so far:

 
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Flyaway

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Checking Out the Mechanisms in Webb’s NIRSpec Instrument


This week, the Webb team has been working on the fourth stage of mirror alignment, called Coarse Phasing, which measures and corrects smaller height differences between the mirror segments.

In the meantime this past week, Webb’s Near-Infrared Spectrograph (NIRSpec) team successfully finished the check-out and initial characterization of three crucial onboard mechanisms. Today, members of the team join us to share more about the inner workings of this instrument, which was contributed by ESA (European Space Agency):

“To work properly as a spectrograph, NIRSpec has three mechanisms: a Filter Wheel Assembly (FWA), a Grating Wheel Assembly (GWA), and a Refocus Mechanism Assembly (RMA). The gratings in the GWA spread the incoming light over its colors or wavelengths to make a spectrum. The filters in the FWA block the wavelengths that are outside the range of interest to prevent contamination between different optical paths, or ‘orders.’ The RMA adjusts the instrument focus.
This NIRSpec diagram shows the placement of the Filter Wheel Assembly (FWA), a Grating Wheel Assembly (GWA), and a Refocus Mechanism Assembly (RMA). Credit: STScI

“We operated the Filter Wheel Assembly first, cycling it through all eight of its positions in both forward and reverse directions. Those eight filter wheel positions include five long-pass order-separation filters, two finite-band target acquisition filters, and an ‘opaque’ position that serves as the instrument shutter. At each position, we recorded a set of reference data. This data showed us how well the wheel was moving and how accurately it settled into each position. Between each FWA position, we downloaded ‘high-capacity buffer’ data from the positioning sensors, and the NIRSpec team analyzed the data. The data showed that the wheel moved very well even in the first attempt.

“We then used a very similar procedure for the Grating Wheel Assembly, which also performed excellently the first time. The GWA is shaped like a miniature Ferris wheel and holds eight optical elements, consisting of six diffraction gratings, one prism, and a mirror. These dispersers separate the incoming light by wavelength, generating spectra that are detected by NIRSpec’s sensor chips.

“The Refocus Mechanism Assembly includes a linear translation stage that holds two flat mirrors. It will be used to fine-tune the instrument focus, compensating for any change in the overall focus position of the Webb telescope that may occur throughout the observatory’s lifetime. After various initial retrievals of the RMA telemetry acquisition chain, the mechanism was moved forward a few hundred steps from launch position. Just like with the FWA and GWA, we used high-capacity buffer readouts to collect reference datasets. After the initial move, we commanded the RMA mirrors to their previous best focus position; successful completions of this test showed us that the RMA is a well-behaved and healthy mechanism.
The NIRSpec thermal team from Airbus Germany of Taufkirchen and Immenstaad at the Space Telescope Science Institute in Baltimore. Credit: STScI

“In the coming months, the NIRSpec team will continue their commissioning efforts. The whole team is very much looking forward to the start of science observations this summer!”

–Maurice Te Plate, Webb NIRSpec systems engineer, European Space Agency; Tim Rawle, Webb NIRSpec instrument scientist, European Space Agency; and Ralf Ehrenwinkler, project manager, NIRSpec post-delivery support, Airbus Defence and Space

By Jonathan Gardner, Webb deputy senior project scientist, NASA’s Goddard Space Flight Center

And Alexandra Lockwood, project scientist for Webb science communications, Space Telescope Science Institute
 

Flyaway

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March 14, 2022
MEDIA ADVISORY M22-034
NASA to Discuss Progress as Webb Telescope’s Mirrors Align

NASA will hold a virtual media briefing at noon EDT Wednesday, March 16, to provide an update on the James Webb Space Telescope’s mirror alignment. The briefing will air live on NASA TV, the NASA app, and the agency’s website.

Participants will share progress made in aligning Webb’s mirrors, resulting in a fully focused image of a single star. NASA will make imagery demonstrating the completion of this milestone available on the agency’s website at 11:30 a.m., prior to the briefing.

Briefing participants include:

Thomas Zurbuchen, associate administrator, Science Mission Directorate, NASA Headquarters in Washington
Lee Feinberg, Webb optical telescope element manager, NASA’s Goddard Space Flight Center in Greenbelt, Maryland
Marshall Perrin, Webb deputy telescope scientist, Space Telescope Science Institute in Baltimore
Jane Rigby, Webb operations project scientist, Goddard
Erin Wolf, Webb program manager, Ball Aerospace in Broomfield, Colorado

To ask questions during the briefing, media must RSVP no later than two hours before the start of the event to Laura Betz at: laura.e.betz@nasa.gov. Media and members of the public may also ask questions on social media using #UnfoldtheUniverse.

NASA’s media accreditation policy is available online.

In recent weeks, the Webb team successfully captured starlight through each of Webb’s 18 mirror segments. The team then refined and stacked those 18 individual dots of light on top of one another to form an initial alignment image of a single star. Since then, in stages of alignment called “coarse phasing" and "fine phasing,” engineers have made smaller adjustments to the positions of Webb’s 18 primary mirror segments so they act as a single mirror, producing a sharp and focused image of a single star.

Webb, an international partnership with ESA (European Space Agency) and the Canadian Space Agency, launched Dec. 25 from Europe’s Spaceport in Kourou, French Guiana. After unfolding into its final form in space and successfully reaching its destination 1 million miles from Earth, the observatory is now in the process of preparing for science operations. The Webb team will release the telescope’s first science images and data this summer after completing telescope alignment and preparing the instruments.

Webb will explore every phase of cosmic history – from within our solar system to the most distant observable galaxies in the early universe, and everything in between. Webb will reveal new and unexpected discoveries and help humanity understand the origins of the universe and our place in it.

NASA has a digital media kit, as well as image and video galleries, available online. The public also can follow Webb’s progress via a “Where is Webb?” interactive tracker.

For more information about the Webb mission, visit:

 

Flyaway

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NASA News Releases
Wed 3/16/2022 11:47 AM
March 16, 2022
RELEASE 22-024
NASA’s Webb Reaches Alignment Milestone, Optics Working Successfully

Following the completion of critical mirror alignment steps, NASA’s James Webb Space Telescope team expects that Webb’s optical performance will be able to meet or exceed the science goals the observatory was built to achieve.

On March 11, the Webb team completed the stage of alignment known as “fine phasing.” At this key stage in the commissioning of Webb’s Optical Telescope Element, every optical parameter that has been checked and tested is performing at, or above, expectations. The team also found no critical issues and no measurable contamination or blockages to Webb’s optical path. The observatory is able to successfully gather light from distant objects and deliver it to its instruments without issue.


Although there are months to go before Webb ultimately delivers its new view of the cosmos, achieving this milestone means the team is confident that Webb’s first-of-its-kind optical system is working as well as possible.

“More than 20 years ago, the Webb team set out to build the most powerful telescope that anyone has ever put in space and came up with an audacious optical design to meet demanding science goals,” said Thomas Zurbuchen, associate administrator for NASA’s Science Mission Directorate in Washington. “Today we can say that design is going to deliver.”

While some of the largest ground-based telescopes on Earth use segmented primary mirrors, Webb is the first telescope in space to use such a design. The 21-foot, 4-inch (6.5-meter) primary mirror – much too big to fit inside a rocket fairing – is made up of 18 hexagonal, beryllium mirror segments. It had to be folded up for launch and then unfolded in space before each mirror was adjusted – to within nanometers – to form a single mirror surface.

“In addition to enabling the incredible science that Webb will achieve, the teams that designed, built, tested, launched, and now operate this observatory have pioneered a new way to build space telescopes,” said Lee Feinberg, Webb optical telescope element manager at NASA’s Goddard Space Flight Center in Greenbelt, Maryland.

With the fine phasing stage of the telescope’s alignment complete, the team has now fully aligned Webb’s primary imager, the Near-Infrared Camera, to the observatory’s mirrors.

“We have fully aligned and focused the telescope on a star, and the performance is beating specifications. We are excited about what this means for science,” said Ritva Keski-Kuha, deputy optical telescope element manager for Webb at NASA Goddard. “We now know we have built the right telescope.”

Over the next six weeks, the team will proceed through the remaining alignment steps before final science instrument preparations. The team will further align the telescope to include the Near-Infrared Spectrograph, Mid-Infrared Instrument, and Near InfraRed Imager and Slitless Spectrograph. In this phase of the process, an algorithm will evaluate the performance of each instrument and then calculate the final corrections needed to achieve a well-aligned telescope across all science instruments. Following this, Webb’s final alignment step will begin, and the team will adjust any small, residual positioning errors in the mirror segments.

The team is on track to conclude all aspects of Optical Telescope Element alignment by early May, if not sooner, before moving on to approximately two months of science instrument preparations. Webb’s first full-resolution imagery and science data will be released in the summer.

Webb is the world's premier space science observatory and once fully operational, will help solve mysteries in 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 program led by NASA with its partners at ESA (European Space Agency) and the Canadian Space Agency.

For more information about the Webb mission, visit:

 

Flyaway

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NMaude

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The Goddard Space Flight Centre has just had a press-briefing about the latest news concerning the commissioning of the JWST:

 

Flyaway

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Webb Completes First Multi-Instrument Alignment

The sixth stage of aligning NASA’s James Webb Space Telescope’s mirrors to its scientific instruments so they will create the most accurate and focused images possible has concluded. While the Mid-Infrared Instrument (MIRI) continues its cooldown, optics teams have successfully aligned the rest of the observatory’s onboard instruments to Webb’s mirrors. Previous alignment efforts were so accurate that the team concluded no additional adjustments to the secondary mirror are necessary until the seventh and final stage, which will involve MIRI when it has fully cooled.

“As a general rule, the commissioning process starts with coarse corrections and then moves into fine corrections. The early secondary mirror coarse corrections, however, were so successful that the fine corrections in the first iteration of Phase Six were unnecessary,” said Chanda Walker, Webb wavefront sensing and control scientist, Ball Aerospace. “This accomplishment was due to many years of planning and great teamwork among the wavefront sensing team.”

Throughout the majority of the alignment process, Webb’s 18 hexagonal mirrors and secondary mirror were focused into alignment to the Near-Infrared Camera (NIRCam) instrument only. Upon completing this most recent step, the observatory is now aligned to the Fine Guidance Sensor (FGS), the Near-Infrared Slitless Spectrograph (NIRISS), and the Near-Infrared Spectrometer (NIRSpec) as well as NIRCam.

Once MIRI fully cools to its cryogenic operating temperature in the weeks ahead, a second multi-instrument alignment will occur to make final adjustments to the instruments and mirrors if needed. When the telescope is fully aligned and able to deliver focused light to each instrument, a key decision meeting will occur to confirm the end of aligning the James Webb Space Telescope. The team will then transition from alignment efforts to commissioning each instrument for scientific operations, which are expected to begin this summer.

 

Hobbes

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Something new that has been discovered from the calibration star shot:

Those are more likely to be image artifacts than anything new. That video channel is a low-effort spammer, he's done dozens of videos just panning around the same JWST alignment image.
 

Flyaway

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Something new that has been discovered from the calibration star shot:

Those are more likely to be image artifacts than anything new. That video channel is a low-effort spammer, he's done dozens of videos just panning around the same JWST alignment image.
All people have to do is be patient a bit longer and wait for the real data to start flowing back from JWST.
 

FighterJock

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Something new that has been discovered from the calibration star shot:

Those are more likely to be image artifacts than anything new. That video channel is a low-effort spammer, he's done dozens of videos just panning around the same JWST alignment image.
All people have to do is be patient a bit longer and wait for the real data to start flowing back from JWST.

Quite right Flyaway, As far as the initial photos go it is better to wait until the real images start to come from the JWST it is just early days.
 

Flyaway

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Northrop Grumman Enables James Webb Space Telescope’s Coldest Instrument to Reach Operational Temperature

April 13, 2022

REDONDO BEACH, Calif. – April 13, 2022 – NASA’s James Webb Space Telescope, built in partnership with Northrop Grumman Corporation (NYSE: NOC), is one step closer to being fully commissioned. Enabled by Northrop Grumman cryocooler technology, the system has cooled the Mid-Infrared Instrument (MIRI) to its operational cryogenic temperature, a critical step toward first science.

Northrop Grumman Enables James Webb Space Telescopes Coldest Instrument to Reach Operational Temperature_1
Inside Northrop Grumman’s Space Park cleanroom in Redondo Beach, Calif., a technician is raised by a scissor lift to inspect the fully assembled and tested James Webb Space Telescope. Photo Credit: Northrop Grumman
“Reaching MIRI’s operational temperature is a major step toward science and all the astounding discoveries Webb will uncover for years to come,” said Charlie Atkinson, chief engineer, James Webb Space Telescope, Northrop Grumman. “The success of this remarkable milestone is a testament to the dedication of engineers and scientists and the many years of practice.”

Webb’s cryocooler is an advanced machine that operates as an internal refrigerator to establish and maintain the right cryogenic temperature for the MIRI. The cryocooler keeps sensors extremely cold so the MIRI can observe the skies and capture light from billions of years ago. To date, Northrop Grumman has delivered over 50 space flight cryocoolers with an accumulated 300 years of combined on-orbit operations.

Northrop Grumman Enables James Webb Space Telescopes Coldest Instrument to Reach Operational Temperature_2
Engineers installing MIRI onto the JWST at NASA’s Goddard Spaceflight Center in 2013. Photo Credit: NASA/Chris Gunn
Webb’s suite of scientific instruments, MIRI included, spent the last three months passively cooling off in deep space to 90 kelvin – minus 298 Fahrenheit or minus 183 Celsius – with the help of Webb’s massive sunshield. The size of a tennis court, the sunshield protects the telescope from light and heat emitted from the sun, Earth and moon, and the observatory itself. Last week, Webb’s MIRI reached its operating cryogenic temperature of below seven kelvin, which is minus 448 Fahrenheit or minus 266 Celsius.

Taking Webb from the drawing board and making it a reality was an enormous collaborative effort between NASA, international partners, and industry. As the largest, most complex and powerful space telescope ever built, Webb required 10 technological inventions, including revolutionary optics, detectors and MIRI’s advanced cryocooler.

 

Flyaway

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JWST has almost reached its final temperature.

The secondary mirror, which is held out at the end of its support structure, is ready to go. Being far away from any of the heat sources of the telescope’s instruments, it is currently at 29.4 kelvins. The 18 primary mirror segments are almost cooled down enough to begin observations. Currently their temperatures range from 34.4 to 54.5 kelvins. The team operating the telescope would like to see them cool down another 0.5 to 2 kelvins.

 

Josh_TN

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Wow...it gathers so much light, it makes the galaxy seem positively full. It never occurred to me until just now that the biggest problem the the Webb program is going have is finding enough time and power to process the raw data.
 

Flyaway

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Wow...it gathers so much light, it makes the galaxy seem positively full. It never occurred to me until just now that the biggest problem the the Webb program is going have is finding enough time and power to process the raw data.
I thought you were going to start quoting from 2001: A Space Odyessy.
 

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