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NASA’s Webb Telescope mirror crushes “most optimistic predictions” after final alignment

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4 years ago

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NASA says that the nascent James Webb Space Telescope’s (JWST) “optical performance…continues to be better than the…most optimistic predictions” after completing the alignment of its record-breaking mirror.

Between 7 and 14 years behind schedule and over budget by a factor of 2 to 10, an Arianespace Ariane 5 rocket sent the Webb Telescope on its way to deep space on December 25th, 2021. Weighing 6.2 tons (~13,600 lb), JWST was almost half as heavy at liftoff as NASA’s iconic Hubble Space Telescope despite packing an unprecedented origami-like mirror with more than six times Hubble’s total collecting area. The combination of extreme mass reduction and extraordinary complexity required to launch such a large mirror so far from Earth with a rocket like Ariane 5 helps to partially explain why the Webb Telescope took so long (~18 years) and cost so much (~$9.7 billion) to design, develop, and build.

Nonetheless, launch it finally did. Ariane 5 did most of the work, sending the telescope on a trajectory that – with some help from its onboard thrusters – would guide it to the Sun-Earth L2 Lagrange point located some 1.5 million kilometers (~950,000 miles) from Earth. In perhaps the largest relief in the history of space-based observatories, the Webb Telescope’s immensely complex deployment process was then completed without a single major issue. 30 days after liftoff, the telescope – fully deployed – reached its operational orbit.

For the past four months, in comparison, almost all JWST work has focused on the less visible and far smaller processes of alignment and calibration. Each of JWST’s 18 main mirror segments has slowly but surely inched micrometer by micrometer into position while large swaths of the telescope slowly cooled to ambient temperatures – essential for maximum performance. Simultaneously, all of Webb’s primary instruments have achieved first light and entered the early phases of calibration and commissioning. Only after the instruments are painstakingly calibrated, the mirror is perfectly aligned, and crucial hardware is chilled to temperatures as low as -449°F (-267°C) can Webb begin to observe the universe and revolutionize large subsets of space science.

An inward view of the fruits of alignment. (NASA)

The first and most important step – mirror alignment – is now complete. The alignment process began in February 2022, six weeks after liftoff. First, images were captured with the unaligned mirror to help determine exactly what condition it was in. One by one, each of Webb’s 18 mirror segments were individually moved to determine which image each mirror was responsible for, which then allowed ground controllers to properly focus each mirror’s view of a target star. In a process known as “coarse phasing,” once those 18 points of light well-resolved and linked to a specific mirror segment, the segments were gradually steered on top of each other to produce a single image.

“Coarse” heavily undersells the almost unfathomable precision required to complete the step. To reach its full potential, each of the Webb Telescope’s mirror segments must be aligned to within 50 nanometers of each other. According to NASA, “if the Webb primary mirror were the size of the United States, each segment would be the size of Texas, and the team would need to line the height of those Texas-sized segments up with each other to an accuracy of about 1.5 inches.”

The product of coarse phasing – beautiful but not yet scientifically useful. (NASA)

Fine phasing followed, involving an even more esoteric set of processes designed to focus the mirror as perfectly as possible. The resulting image was then tweaked to properly align it over the field of view of each of the Webb Telescope’s four main scientific instruments. Finally, some steps of the seven-step alignment process were redone or refined to fully optimize the mirror to the liking of its Earthbound creators and prospective users.

Ultimately, Webb Telescope alignment was extraordinarily successful, producing an image sharper and cleaner than even the “most optimistic predictions” made by its engineers. NASA says that the image is so detailed that it has effectively reached the physical resolution limit for a mirror the size of the Webb Telescope’s, meaning that it would have to violate the known laws of physics to resolve any more detail.

https://twitter.com/AndrasGaspar/status/1520184730985148418
JWST’s first images with a fully aligned mirror. (NASA)

With mirror alignment complete, JWST has just one main hurdle left before science operations can begin: instrument commissioning. Commissioning is a catch-all phrase that covers a wide range of calibration, analysis, experiments, and optimization required to verify that JWST’s four main instruments are behaving as expected and accomplishing the work they were designed to do as accurately and reliably as possible.

At some point, the use of extraordinarily complex scientific instruments becomes more akin to an art form, and some degree of trust must be built up between scientists and their hopeful tools of the trade before they can confidently set chisel to marble and begin delving into the universe at unprecedented breadth and detail. If commissioning proceeds as smoothly as deployment and alignment, the JWST team could be ready to capture and share the telescope’s first actionable observations of the cosmos as early as July 2022.

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Eric Ralph is Teslarati's senior spaceflight reporter and has been covering the industry in some capacity for almost half a decade, largely spurred in 2016 by a trip to Mexico to watch Elon Musk reveal SpaceX's plans for Mars in person. Aside from spreading interest and excitement about spaceflight far and wide, his primary goal is to cover humanity's ongoing efforts to expand beyond Earth to the Moon, Mars, and elsewhere.

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Tesla Model Y L’s new features flexed at unveiling event at Diner

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3 hours ago

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July 31, 2026

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Tesla Model Y L in a field
Credit: Tesla

Tesla flexed the new features of the Model Y L with a dedicated media event at the company’s Diner on Santa Monica Boulevard in Los Angeles.

The Model Y L is the extended-wheelbase version of the all-electric crossover, which has been voted the best-selling car in the world on three occasions. The vehicle is already rolling off production lines at Gigafactory Texas, and first deliveries are slated to take place later this year.

Tesla brings Model Y L ‘Launch Series’ to the U.S. at $61,990

Teslarati was invited to the event, but due to some scheduling conflicts, we could not make it to Los Angeles. Instead, we will have our hands on a media unit sometime in August, so we’ll be able to spend some more extended time with the Model Y L.

However, plenty of those who made it to LA shared some cool features that set the Model Y L apart from the Model Y.

Multi-Row Climate Control

Tesla fitted the Model Y L with full climate control on all three rows on the front screen. It can be adjusted by selecting which row you’d like to modify on the right-hand side of the touch screen:

Better Rear Window Visibility

One of the strangest things about the Model Y, especially the Juniper iteration, is the rear window has extremely limited visibility when looking into the rearview mirror.

Tesla has improved upon this with the Model Y L:

PowerShare will be included

Model Y L will come with PowerShare in North America, with an 11.5kW output to your home. Tesla said it would require Powerwall 3 for operation.

Wireless Charging Pad

There has been some speculation that Tesla would upgrade the wireless charging pads in the United States, but this is not the case.

Tesla owner fixes common feature complaint with crafty DIY retrofit

Tesla confirmed that it does not come with the cooled pads as the Y L in China does. This is because North America has not adopted Qi charging yet.

Thermal Management Improvements

These improvements in the Model Y L were seen with thermal management:

  • Up to 15% faster cabin cooling
  • +23% thermal efficiency gained in hot weather, 7 miles of real-world range gained
  • 8x more solar energy reflection off of glass roof
  • 30% reduction in solar energy entering the cabin

Demand

Tesla said the Model Y L is almost sold out in the U.S. It comes with

  • 1 year of FSD Supervised
  • 1 year of Supercharging
  • 1 year of Premium Connectivity
  • Free exterior paint color, interior, and wheel option at no additional cost
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Elon Musk

Tesla CEO Elon Musk denies ridiculous Gigafactory Shanghai rumor

Published

5 hours ago

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July 31, 2026

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(Credit: Tesla)

Tesla CEO Elon Musk took to his social media platform X on Thursday night to deny a ridiculous rumor regarding the sale of the company’s Chinese vehicle production plant, Gigafactory Shanghai.

On Thursday, the Wall Street Journal, citing sources familiar with the matter, claimed in a scathing new report that Tesla was exploring a potential sale of the entire China business in an effort to help bolster a potential merger between SpaceX and Tesla.

Musk immediately denied the rumor not once but twice, initially calling it “fake news,” and then calling it “absurdly fake news” in a separate post just a few moments later:

The original poster of the Wall Street Journal article that Musk saw deleted the initial post sharing the headline and the rumored sale of Tesla’s China business.

The report seemed absolutely and unequivocally false to begin with; Tesla’s business in China is among the most important pieces of the company’s business. Not only does the factory supply vehicles for the domestic market, but also for various other markets in Asia and Europe.

China is also one of the largest automotive markets in the world, and Tesla has performed well there despite the robust competition.

The speculation regarding a Tesla and SpaceX merger has started to gain steam this year as the space exploration company went public just a month ago. There has been speculation that Musk will bridge all of his companies under one “umbrella company,” and analysts believe this could happen before the end of the decade.

The Tesla and SpaceX merger everyone is talking about is quietly building

This is the latest iteration of Musk’s very evident war on mainstream media. Reports regarding any of Musk’s companies are quick to get the dreaded “false” or “fake news” response from the CEO when they are unfounded.

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Elon Musk

Tesla AI boss reveals how big Optimus is going to get

Tesla’s Optimus chief corrected himself on X, confirming a staggering 10 million robot production target.

Published

13 hours ago

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July 31, 2026

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Tesla Optimus Gen 3 [Credit: Tesla]

Tesla’s Optimus program has a new number attached to it, after Ashok Elluswamy, the executive who has run the humanoid robot program since June 2025, posted a three word correction on X Thursday, “Correction, 10 million robots.”

The line clarifies the long term annual capacity Tesla is building toward its planned second Optimus production line at Gigafactory Texas, a figure Musk has cited repeatedly since last year’s shareholder meeting.

The scale is worth noting, because ten million robots a year would mean Tesla building more units annually than most countries sell in new cars. Tesla has framed this as a second line, not the first. The buildout is happening in two phases: a roughly one million unit per year line inside Tesla’s Fremont factory, installed on the floor space vacated when Model S and Model X production ended earlier this year, and a much larger dedicated facility under construction at Giga Texas that broke ground on its first steel structure in May. That Texas facility is the one Elluswamy’s correction refers to, and is expected to reach volume production sometime in 2027.

Tesla Optimus project fires up as Musk sees production line progress

Elluswamy took over Optimus from Milan Kovac last summer and has spent the months since talking up the program’s trajectory. Elon Musk has also floated the ten million figure at Tesla’s 2025 shareholder meeting.

Ending Model S and Model X production to make room for the first Optimus line was one of the more consequential manufacturing decisions in the company’s recent history, retiring two flagship vehicles in favor of a robot that has yet to enter mass production. Musk has previously estimated per unit production costs at $20,000 to $25,000 once Tesla reaches a million units a year, though he hasn’t said what that cost looks like at ten times the volume.

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