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NASA’s Webb Telescope mirror crushes “most optimistic predictions” after final alignment
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.
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.”
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.
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.
In Pennsylvania, we got between 10 and 12 inches of snow over the weekend as a nasty Winter storm ripped through a large portion of the country, bringing snow to some areas and nasty ice storms to others.
I have had a Model Y Performance for the week courtesy of Tesla, which got the car to me last Monday. Today was my last full day with it before I take it back to my local showroom, and with all the accumulation on it, I decided to run a cool little experiment: How long would it take for Tesla’s Defrost feature to melt 8 inches of snow?
Tesla’s Defrost feature is one of the best and most underrated that the car has in its arsenal. While every car out there has a defrost setting, Tesla’s can be activated through the Smartphone App and is one of the better-performing systems in my opinion.
It has come in handy a lot through the Fall and Winter, helping clear up my windshield more efficiently while also clearing up more of the front glass than other cars I’ve owned.
The test was simple: don’t touch any of the ice or snow with my ice scraper, and let the car do all the work, no matter how long it took. Of course, it would be quicker to just clear the ice off manually, but I really wanted to see how long it would take.
Tesla Model Y heat pump takes on Model S resistive heating in defrosting showdown
Observations
I started this test at around 10:30 a.m. It was still pretty cloudy and cold out, and I knew the latter portion of the test would get some help from the Sun as it was expected to come out around noon, maybe a little bit after.
I cranked it up and set my iPhone up on a tripod, and activated the Time Lapse feature in the Camera settings.
The rest of the test was sitting and waiting.
It didn’t take long to see some difference. In fact, by the 20-minute mark, there was some notable melting of snow and ice along the sides of the windshield near the A Pillar.
However, this test was not one that was “efficient” in any manner; it took about three hours and 40 minutes to get the snow to a point where I would feel comfortable driving out in public. In no way would I do this normally; I simply wanted to see how it would do with a massive accumulation of snow.
It did well, but in the future, I’ll stick to clearing it off manually and using the Defrost setting for clearing up some ice before the gym in the morning.
Check out the video of the test below:
❄️ How long will it take for the Tesla Model Y Performance to defrost and melt ONE FOOT of snow after a blizzard?
Let’s find out: pic.twitter.com/Zmfeveap1x
— TESLARATI (@Teslarati) January 26, 2026
Tesla Robotaxi ride-hailing without a Safety Monitor is proving to be a difficult task, according to some riders who made the journey to Austin to attempt to ride in one of its vehicles that has zero supervision.
Last week, Tesla officially removed Safety Monitors from some — not all — of its Robotaxi vehicles in Austin, Texas, answering skeptics who said the vehicles still needed supervision to operate safely and efficiently.
BREAKING: Tesla launches public Robotaxi rides in Austin with no Safety Monitor
Tesla aimed to remove Safety Monitors before the end of 2025, and it did, but only to company employees. It made the move last week to open the rides to the public, just a couple of weeks late to its original goal, but the accomplishment was impressive, nonetheless.
However, the small number of Robotaxis that are operating without Safety Monitors has proven difficult to hail for a ride. David Moss, who has gained notoriety recently as the person who has traveled over 10,000 miles in his Tesla on Full Self-Driving v14 without any interventions, made it to Austin last week.
He has tried to get a ride in a Safety Monitor-less Robotaxi for the better part of four days, and after 38 attempts, he still has yet to grab one:
Wow just wow!
It’s 8:30PM, 29° out ice storm hailing & Tesla Robotaxi service has turned back on!
Waymo is offline & vast majority of humans are home in the storm
Ride 38 was still supervised but by far most impressive yet pic.twitter.com/1aUnJkcYm8
— David Moss (@DavidMoss) January 25, 2026
Tesla said last week that it was rolling out a controlled test of the Safety Monitor-less Robotaxis. Ashok Elluswamy, who heads the AI program at Tesla, confirmed that the company was “starting with a few unsupervised vehicles mixed in with the broader Robotaxi fleet with Safety Monitors,” and that “the ratio will increase over time.”
This is a good strategy that prioritizes safety and keeps the company’s controlled rollout at the forefront of the Robotaxi rollout.
However, it will be interesting to see how quickly the company can scale these completely monitor-less rides. It has proven to be extremely difficult to get one, but that is understandable considering only a handful of the cars in the entire Austin fleet are operating with no supervision within the vehicle.
Tesla has given its biggest hint that Full Self-Driving in Europe is imminent, as a new feature seems to show that the company is preparing for frequent border crossings.
Tesla owner and influencer BLKMDL3, also known as Zack, recently took his Tesla to the border of California and Mexico at Tijuana, and at the international crossing, Full Self-Driving showed an interesting message: “Upcoming country border — FSD (Supervised) will become unavailable.”
FSD now shows a new message when approaching an international border crossing.
Stayed engaged the whole way as we crossed the border and worked great in Mexico! pic.twitter.com/bDzyLnyq0g
— Zack (@BLKMDL3) January 26, 2026
Due to regulatory approvals, once a Tesla operating on Full Self-Driving enters a new country, it is required to comply with the laws and regulations that are applicable to that territory. Even if legal, it seems Tesla will shut off FSD temporarily, confirming it is in a location where operation is approved.
This is something that will be extremely important in Europe, as crossing borders there is like crossing states in the U.S.; it’s pretty frequent compared to life in America, Canada, and Mexico.
Tesla has been working to get FSD approved in Europe for several years, and it has been getting close to being able to offer it to owners on the continent. However, it is still working through a lot of the red tape that is necessary for European regulators to approve use of the system on their continent.
This feature seems to be one that would be extremely useful in Europe, considering the fact that crossing borders into other countries is much more frequent than here in the U.S., and would cater to an area where approvals would differ.
Tesla has been testing FSD in Spain, France, England, and other European countries, and plans to continue expanding this effort. European owners have been fighting for a very long time to utilize the functionality, but the red tape has been the biggest bottleneck in the process.
Tesla Europe builds momentum with expanding FSD demos and regional launches
Tesla operates Full Self-Driving in the United States, China, Canada, Mexico, Puerto Rico, Australia, New Zealand, and South Korea.
Tesla winter weather test: How long does it take to melt 8 inches of snow?
Tesla Robotaxi ride-hailing without a Safety Monitor proves to be difficult
