How the James Webb Space Telescope exceeded all expectations

On December 25, 2021, the James Webb Space Telescope was launched into space.

On December 25, 2021, the James Webb Space Telescope was successfully launched into orbit from an Ariane 5 rocket. Rocket launches were the only way we were able to propel a spacecraft great distances through space.

(credit: ESA-CNES-ArianeSpace / Optique Vidéo du CSG / NASA TV)

The plan envisioned six months of posting, cooling and calibration.

The secondary mirror diffusion sequence is shown in this time-lapse image. It should be located exactly a little less than 24 feet, or just over 7 meters from the primary mirror. This was one of a few hundred steps that should go as planned, without fail, to bring a fully functional JWST online.

(credit: NASA/James Webb Space Telescope Team)

After that, scientific processes will begin, resulting in a life expectancy of 5 to 10 years.

James Webb Space Telescope

When all optics are deployed correctly and the telescope is fully calibrated, James Webb should be able to view any extraterrestrial object in the universe with unprecedented accuracy, with its primary and secondary mirrors focusing light on the instruments, where data can be taken, scaled down, and returned to Earth.

(credit: NASA/James Webb Space Telescope Team)

However, on April 28, 2022, Align each tool It was completed, with an expected lifespan of up to 20 years.

This image shows the 18 individual segments that make up the primary mirror of James Webb, and the three independent sets of mirrors, labeled with the letters A, B, and C and numbers 1 through 6, which correspond to the position each mirror is fixed to at the present time. scattered telescope.

(credit: NASA/James Webb Space Telescope Team)

The performance of both the telescope and the team was amazing, generally exceeding expectations.

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This multi-panel image shows the detail returned by both JWST instruments in the same pointing/field of view. For the first time, all instruments across the full field of view have been correctly and completely calibrated, bringing JWST one step closer to being ready to begin scientific operations.

(credit: NASA / STScI)

First: the original fuel saved during launch and intended for course correction.

With the solar array deployed 29 minutes after launch, and roughly 4 minutes ahead of schedule, it’s clear that NASA’s James Webb Space Telescope is up and running, receiving power, and is on its way to its final destination. The launch was an unparalleled success.

(credit: NASA TV / YouTube)

JWST arrived at its destination, point L2 Lagrange, ahead of schedule.

Each planet orbits a star that has five positions around it, Lagrangian points, that common orbit. An object located precisely at L1, L2, L3, L4, or L5 will continue to orbit the Sun for exactly the same period as the Earth orbits, which means that the distance between Earth and the spacecraft will be constant. L1, L2, and L3 are unstable equilibrium points, and require periodic trajectory corrections to maintain the spacecraft’s position there, while L4 and L5 are stable. Webb has successfully inserted himself into orbit around L2, and it must always be away from the Sun for cooling purposes.

(credit: NASA)

Each component is deployed properly, and cooled as planned.

The current state of the JWST shows how far it has gone through each step of its deployment, including the calibration of various components and the temperature of each device. Scientific operations are about to begin.

(credit: NASA / JWST Team / STScI)

in early February, 7 steps alignment / commissioning The process has begun.

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James Webb Hubble

Part of the Hubble eXtreme Deep Field imaged for a total of 23 days, in contrast to the simulated view predicted by JWST in the infrared. By choosing its targets wisely, the James Webb Space Telescope should be able to reveal extraordinary details about the farthest objects in the universe that no other observatory can hope to reveal. Once the calibration is complete, this type of scientific work can begin.

(credit: NASA/ESA and Hubble/HUDF Team; JADES Collaboration for NIRCam Simulation)

First, the images produced by each mirror clip were determined.

James Webb nails

This mosaic image was created by pointing the telescope at a bright, isolated star in the constellation Ursa Major known as HD 84406. This star was chosen specifically because it is easy to identify and not crowded with other stars of similar brightness, which helps reduce the background. confusion. Each point within the mosaic is marked by the corresponding primary mirror segment that captured it. These preliminary results closely match expectations and simulations.

(credit: NASA)

Second, the images were aligned, and then the third were stacked.

This three-panel animation shows the difference between the 18 individual images not aligned, those same images after each segment was better composed, and then the final image where the individual images from all 18 mirrors were stacked and added together. The pattern made by this star, known as a “nightmare snowflake” could be improved with better calibration.

(credits: NASA/STScI, Prepared by E. Siegel)

Fourth, 18 small telescopes were made into one large telescope.

After image stacking, where all the light is placed in one place on the detector, the sections still need to be aligned with each other at a resolution below the wavelength of the light. It measures the coarse phase and corrects the vertical displacement (ie the piston difference) of the mirror segments. Small piston errors result in fewer “razor shaft” lines in this NASA simulation.

(credit: NASA)

Fifthly, the NIRCam micro-gradient occurred, resulting in the creation of The first fully focused image.

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James Webb nails

The first minute-phase image ever released by NASA’s James Webb Space Telescope shows a single image of a star, complete with six notable (and two less prominent) diffractions, with a background of stars and galaxies revealed behind it. As cool as this image is, it’s probably the worst James Webb Space Telescope image you’ll ever see from here.

(credit: NASA / STScI)

JWST Unique set of nails It arises from the optical design of the telescope.

Point propagation function for the James Webb Space Telescope, as predicted in a 2007 document. The four factors of the hexagonal (non-circular) primary mirror consist of an array of 18 tiled hexagons, each with approximately 4 mm gaps, and three support struts to hold the secondary mirror in place, They all create an inevitable series of spikes that appear around the bright spot sources imaged with JWST.

(credit: R.B. Makidon, S. Casertano, C. Cox & R. van der Marel, STScI/NASA/AURA)

Sixth, alignment coverage spanned across the JWST toolkit and the entire field of view.

After optimizing the phases, the telescope is well aligned in only one spot in the NIRCam’s field of view. By making measurements at multiple field points across each instrument, intensity differences can be minimized to perfection, achieving a well-coordinated telescope across all scientific instruments.

(credit: NASA)

Seventh, the final iterative corrections terminated the alignment.

Geometric images of highly focused stars in each instrument’s field of view show that the telescope is perfectly aligned and in focus. In this test, Webb pointed to a portion of the Large Magellanic Cloud, a small satellite galaxy of the Milky Way, providing a dense field of hundreds of thousands of stars across all of the observatory’s sensors.

(credit: NASA / STScI)

right Now NircamAnd

Originally, when the first images of JWST’s stunning “8 spiked” star were produced, it was an indication that the spacecraft’s spine camera, NIRCam, had been calibrated at some point. Now, this calibration is across the entire field of view of the JWST, across the full NIRCam field as well as the fields of all the other instruments.

(credit: NASA / STScI)

precision steering sensor,

The JWST Precision Wisdom sensor will track the guiding stars to orient the observatory precisely and accurately, and will take calibration images instead of the images used to extract scientific data.

(credit: NASA / STScI)


Part of the same instrument as the Precision Orientation Sensor, the near-infrared imaging and spectrograph is designed to excel in exoplanet discovery, characterization, and transit spectroscopy. If there are vital hints about exoplanets, the NIRISS instrument should find them.

(credit: NASA / STScI)


NIRSpec is a spectrometer not an imager but can take images, such as the 1.1 μm image shown here, for calibration and target acquisition. The dark areas visible in parts of the NIRSpec data are due to their microshutter array structures, which contain hundreds of thousands of controllable shutters that can be opened or closed to determine which light is being sent to the spectrometer.

(credit: NASA / STScI)

And All MIRI tools are aligned.

Although the James Webb Space Telescope’s MIRI (Intermediate Infrared Instrument) instrument achieves less accuracy due to the long wavelengths it affects, it is also the most powerful instrument in many ways, capable of revealing the most remote features in the universe at all. .

(credit: NASA / STScI)

Just Instrument commissioning and final calibrations Remains.

This is a simulated JWST/NIRCam mosaic generated with JAGUAR and Guitarra to simulate NIRCam images, at the projected depth of JADES Deep. It’s very likely that in his first year of scientific operations, James Webb will break many of the records set by Hubble over the course of 32 years (and counting), including the records for the most distant galaxies and the most distant star.

(credit: C. Williams et al., ApJ, 2018)

With fuel savings and quick alignment, ~More than 20 years of scientific operations will start soon.

Mostly Mute Monday tells an astronomical story with pictures, visuals, and no more than 200 words. taciturn; smile more.

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