Technologies

Major Energy Breakthrough: Milestone Achieved in US Fusion Experiment

For the first time, the National Ignition Facility officially achieved ignition in a fusion reactor.

It was touted as a «major scientific breakthrough» and, it seems, the rumors were true: On Tuesday, scientists at Lawrence Livermore National Laboratory announced that they have, for the first time, achieved net energy gain in a controlled fusion experiment.

«We have taken the first tentative steps toward a clean energy source that could revolutionize the world,» Jill Hruby, administrator of the National Nuclear Security Administration, said in a press conference Tuesday.

The triumph comes courtesy of the National Ignition Facility at LLNL in San Francisco. This facility has long tried to master nuclear fusion — a process that powers the sun and other stars — in an effort to harness the massive amounts of energy released during the reaction because, as Hruby points out, all that energy is «clean» energy.

Despite decades of effort, however, there had been a major kink in these fusion experiments: the amount of energy used to achieve fusion has far outweighed the energy coming out. As part of the NIF mission, scientists had long hoped to achieve «ignition,» where the energy output is «greater than or equal to laser drive energy.»

Some experts have remained skeptical that such a feat was even possible with fusion reactors currently in operation. But slowly, NIF pushed forward. In August last year, LLNL revealed it had come close to this threshold by generating around 1.3 megajoules (a measure of energy) against a laser drive using 1.9 megajoules.

But on Dec. 5, LLNL’s scientists say, they managed to cross the threshold.

They achieved ignition.

All in all, this achievement is cause for celebration. It’s the culmination of decades of scientific research and incremental progress. It’s a critical, albeit small, step forward, to demonstrate that this type of reactor can, in fact, generate energy.

«Reaching ignition in a controlled fusion experiment is an achievement that has come after more than 60 years of global research, development, engineering and experimentation,» Hruby said.

«It’s a scientific milestone,» Arati Prabhakar, policy director for the White House Office of Science and Technology, said during the conference, «but it’s also an engineering marvel.»

Still, a fully operational platform, connected to the grid and used to power homes and businesses, likely remains a few decades away.

«This is one igniting capsule at one time,» Kim Budil, director of LLNL, said. «To realize commercial fusion energy you have to do many things. You have to be able to produce many, many fusion ignition events per minute, and you have to have a robust system of drivers to enable that.»

So how did we get here? And what does the future hold for fusion energy?

Simulating stars

The underlying physics of nuclear fusion has been well understood for almost a century.

Fusion is a reaction between the nuclei of atoms that occurs under extreme conditions, like those present in stars. The sun, for instance, is about 75% hydrogen and, because of the all-encompassing heat and pressure at its core, these hydrogen atoms are squeezed together, fusing to form helium atoms.

If atoms had feelings, it would be easy to say they don’t particularly like being squished together. It takes a lot of energy to do so. Stars are fusion powerhouses; their gravity creates the perfect conditions for a self-sustaining fusion reaction and they keep burning until all their fuel — those atoms — are used up.

This idea forms the basis of fusion reactors.

Building a unit that can artificially re-create the conditions within the sun would allow for an extremely green source of energy. Fusion doesn’t directly produce greenhouse gases, like carbon dioxide and methane, which contribute to global warming.

And critically, a fusion reactor also doesn’t have the downsides of nuclear fission, the splitting of atoms used in nuclear bombs and reactors today.

In other words, a fusion power plant wouldn’t produce the radioactive waste associated with nuclear fission.

The big fusion experiment

The NIF, which takes up the space of around three football fields at LLNL, is the most powerful «inertial confinement fusion» experiment in the world.

In the center of the chamber lies a target: a «hohlraum,» or cylinder-shaped device that houses a tiny capsule. The capsule, about as big as a peppercorn, is filled with isotopes of hydrogen, deuterium and tritium, or D-T fuel, for short. The NIF focuses all 192 lasers at the target, creating extreme heat that produces plasma and kicks off an implosion. As a result, the D-T fuel is subject to extreme temperatures and pressures, fusing the hydrogen isotopes into helium — and a consequence of the reaction is a ton of extra energy and the release of neutrons.

You can think of this experiment as briefly simulating the conditions of a star.

The complicated part, though, is that the reaction also requires a ton of energy to start. Powering the entire laser system used by the NIF requires more than 400 megajoules — but only a small percentage actually hits the hohlraum with each firing of the beams. Previously, the NIF had been able to pretty consistently hit the target with around 2 megajoules from its lasers.

But on Dec. 5, during one run, something changed.

«Last week, for the first time, they designed this experiment so that the fusion fuel stayed hot enough, dense enough and round enough for long enough that it ignited,» Marv Adams, deputy administrator at the NNSA, said during the conference. «And it produced more energy than the lasers had deposited.»

More specifically, scientists at NIF kickstarted a fusion reaction using about 2 megajoules of energy to power the lasers and were able to get about 3 megajoules out. Based on the definition of ignition used by NIF, the benchmark has been passed during this one short pulse.

You might also see that energy gain in a fusion reaction is denoted by a variable, Q.

Like ignition, the Q value can refer to different things for different experiments. But here, it’s referring to the energy input from the lasers versus the energy output from the capsule. If Q = 1, scientists say they have achieved «breakeven,» where energy in equals energy out.

The Q value for this run, for context, was around 1.5.

In the grand scheme of things, the energy created with this Q value is only about enough to boil water in a kettle.

«The calculation of energy gain only considers the energy that hit the target, and not the [very large] energy consumption that goes into supporting the infrastructure,» said Patrick Burr, a nuclear engineer at the University of New South Wales.

The NIF is not the only facility chasing fusion — and inertial confinement is not the only way to kickstart the process. «The more common approach is magnetically confined fusion,» said Richard Garrett, senior advisor on strategic projects at the Australian Nuclear Science and Technology Organization. These reactors use magnetic fields to control the fusion reaction in a gas, typically in a giant, hollow donut reactor known as a tokamak.

Those devices have a much lower density than NIF’s pellets, so temperatures need to be increased to well over 100 million degrees. Garrett said he does not expect the NIF result to accelerate tokamak fusion programs because, fundamentally, the two processes work quite differently.

However, significant progress is also being made with magnetically confined fusion. For instance, the ITER experiment, under construction in France, uses a tokamak and is expected to begin testing in the next decade. It has lofty goals, aiming to achieve a Q greater than 10 and to develop commercial fusion by 2050.

The future of fusion

The experiment at NIF might be transformative for research, but it won’t immediately translate to a fusion energy revolution. This isn’t a power-generating experiment. It’s a proof of concept.

This is a point worth paying attention to today, especially as fusion has often been touted as a way to combat the climate crisis and reduce reliance on fossil fuels or as a salve for the world’s energy problems. Construction and utilization of fusion energy to power homes and businesses is still a ways off — decades, conservatively — and inherently reliant on technological improvements and investment in alternative energy sources.

Generating around 2.5 megajoules of energy when the total input from the laser system is well above 400 megajoules is, of course, not efficient. And in the case of the NIF experiment, it was one short pulse.

Looking further ahead, constant, reliable, long pulses will be required if this is to become sustainable enough to power kettles, homes or entire cities.

«It’s unlikely that fusion power … will save us from climate change,» said Ken Baldwin, a physicist at the Australian National University. If we are to prevent the largest increases in global average temperature, fusion power is likely going to be a little too late.

Other investment is going to come from private companies, which are seeking to operate tokamak fusion reactors in the next few years. For instance, Tokamak Energy in the UK is building a spherical tokamak reactor and seeks to hit breakeven by the middle of this decade.

Then there’s Commonwealth Fusion Systems, spun out of MIT, which is hoping to generate around 400 megawatts of power, enough for tens of thousands of homes, by the 2030s. Modern nuclear power plants can produce almost three times as much.

And as CNET editor Stephen Shankland noted in a recent piece, fusion reactors will also need to compete against solar and wind power — so even with today’s revelatory findings, fusion energy remains entrenched in the experimental phase of its existence.

But we can now cast one eye toward the future.

It may not prevent the worst of climate change but, harnessed to its full potential, it could produce a near-limitless supply of energy for generations to come. It’s one thing to think about the future of energy on Earth and how it will be utilized, but our eyes may fall on horizons even further out — deep space travel could utilize fusion reactors that blast us well beyond the reaches of our sun’s gravity, the very thing that helped teach us about fusion reactions, and into interstellar space.

Perhaps then, we’d remember Dec. 5, 2022, as the first tiny step toward places we dared once only dream about.

Correction, 8:44 a.m. PT: This article initially misstated the amount of energy in the fusion reaction. NIF powered the lasers with about 2 megajoules and produced 3 megajoules as a result.

Technologies

Today’s NYT Connections: Sports Edition Hints and Answers for Feb. 4, #499

Here are hints and the answers for the NYT Connections: Sports Edition puzzle for Feb. 4, No. 499.

Looking for the most recent regular Connections answers? Click here for today’s Connections hints, as well as our daily answers and hints for The New York Times Mini Crossword, Wordle and Strands puzzles.

Today’s Connections: Sports Edition is a tough one. One of the words —«fronton» — might not be known to all the people who attempt the puzzle. There’s also a heavy focus on one specific team, which can be tough if you don’t know that roster well. If today’s puzzle has you stuck but you still want to crack it, keep reading for hints and answers.

Connections: Sports Edition is published by The Athletic, the subscription-based sports journalism site owned by The Times. It doesn’t appear in the NYT Games app, but it does in The Athletic’s own app. Or you can play it for free online.

Read more: NYT Connections: Sports Edition Puzzle Comes Out of Beta

Hints for today’s Connections: Sports Edition groups

Here are four hints for the groupings in today’s Connections: Sports Edition puzzle, ranked from the easiest yellow group to the tough (and sometimes bizarre) purple group.

Yellow group hint: Nice victory!

Green group hint: I’ll give you that guy for this guy.

Blue group hint: Where to play.

Purple group hint: Florida hoops.

Answers for today’s Connections: Sports Edition groups

Yellow group: Win smoothly.

Green group: Fantasy sports trade options.

Blue group: Areas of play, in different sports.

Purple group: Members of the Orlando Magic.

Read more: Wordle Cheat Sheet: Here Are the Most Popular Letters Used in English Words

What are today’s Connections: Sports Edition answers?

The yellow words in today’s Connections

The theme is win smoothly. The four answers are breeze, coast, cruise and waltz.

The green words in today’s Connections

The theme is fantasy sports trade options. The four answers are accept, counter, propose and reject.

The blue words in today’s Connections

The theme is areas of play, in different sports. The four answers are course, court, fronton and rink.

The purple words in today’s Connections

The theme is members of the Orlando Magic. The four answers are Banchero, Bane, Black and Suggs.

Toughest Connections: Sports Edition categories

The Connections: Sports Edition puzzle can be tough, but it really depends on which sports you know the most about. My husband aces anything having to do with Formula 1, my best friend is a hockey buff, and I can answer any question about Minnesota teams.

That said, it’s hard to pick the toughest Connections categories, but here are some I found exceptionally mind-blowing.

#1: Serie A Clubs. Answers: Atalanta, Juventus, Lazio, Roma.

#2: WNBA MVPs. Answers: Catchings, Delle Donne, Fowles and Stewart.

#3: Premier League team nicknames. Answers: Bees, Cherries, Foxes and Hammers.

#4: Homophones of NBA player names. Answers: Barns, Connect, Heart and Hero.

Technologies

Xbox Cloud Gaming Ad-Supported Tier: When Does It Start, How Much Will It Cost and More

Ads could remove the sting of Xbox Game Pass price hikes, but will it be worth it?

Xbox Cloud Gaming is one of the key selling points of Xbox Game Pass, and it generally works well. The service lets gamers stream Xbox titles to a wide range of devices, including phones, tablets, handhelds and select smart TVs from Samsung, LG and Hisense. However, following the Xbox Game Pass price increase from November, streaming alone may not be enough to keep some subscribers on board, which is where an ad-supported tier could come into play.

Microsoft confirmed the existence of an ad-supported tier last year but has not shared details on when it will launch or what it will include. New screenshots shared by players suggest the tier may be arriving soon, though questions remain about how it will work and what limitations it may have.

Don’t miss any of our unbiased tech content and lab-based reviews. Add CNET as a preferred Google source.

When will the Xbox Cloud Gaming ad-supported tier launch?

Microsoft hasn’t made an official announcement yet, but it’s expected to roll out sometime this year, according to Windows Central. Last month, some gamers saw a different loading screen for Xbox Cloud Gaming with a message saying «1 hour of ad-supported play time per session,» which would point to the ads coming soon.

looks like ad-supported Xbox Cloud Gaming is coming soon 👀 pic.twitter.com/c8hAERrVB9

— Tom Warren (@tomwarren) January 17, 2026

How much will the Xbox Cloud Gaming ad-supported tier cost?

In October, Microsoft confirmed it was internally testing the ad-supported tier, and at the time, said it would be free. Going by the load screen message I mentioned earlier, there will likely be a limit on how long people can play on the tier and during internal testing, players would have to watch a 2-minute ad.

What games will be available on the ad-supported tier?

Rumors about the internal testing suggested players would only have access to certain games for free, but the question is, which ones? Microsoft has a significant number of games available to stream, whether it’s purchased digital games or those available with an Xbox Game Pass subscription. Microsoft may allow all the digital games in a player’s library to be streamed and might make a few games available for free on a weekly or monthly basis, similar to the Free Play Days games.

Technologies

My Experience With United’s Starlink Service: How All In-Flight Wi-Fi Should Be

No need to load up devices with movies on long flights. You can stream them — and even live events — on Starlink-equipped United flights.

If I weren’t buckled into a seat, I might not have noticed that I was using in-flight Wi-Fi. When it came to working on my laptop and streaming movies on my phone and tablet, I could have been on my broadband at home.

But instead I was 30,000 feet up connected to Starlink Wi-Fi, on a United Airlines flight between Chicago and Minneapolis and thinking back to all the times I’d fought with expensive, slow, annoying internet access on planes. The ginger ale offered by a friendly attendant was a nice addition, too.

This experience was a demonstration flight on United’s first mainline Boeing 737-800 aircraft to be outfitted with the new satellite hardware. United now offers Starlink Wi-Fi service on 25% of its fleet, which includes 300 regional aircraft and dozens of mainline planes during 2025. It’s aiming to install the low-profile technology on up to 500 aircraft by the end of 2026.

At a time when our phones and smartwatches have satellite connectivity options — helping us reach emergency responders or send text messages when we’re out of range of a cell signal — Starlink and United are providing travelers with an upgraded convenience. What’s more, we’re getting in-flight Wi-Fi with speeds and connectivity that rival what we experience at home or the office.

Air travel presents a conundrum: If you need Wi-Fi in the air and it’s not working, you’re cooked. There’s no stepping out to a coffee shop hotspot or rebooting your home router. In-flight Wi-Fi has improved over the years, but it still feels risky whether it will work well or at all. And you don’t discover that until you’re already in the air.

The plane I traveled on isn’t the first United aircraft carrying Starlink’s satellite Wi-Fi equipment. United began outfitting many of its regional Embraer E175 jets in March after signing a deal with Starlink’s parent company, SpaceX, last year. Although it’s the inaugural United mainline aircraft, Hawaiian Airlines got the jump late last year when it outfitted its Airbus planes with the technology.

The Boeing 737-800 I flew on went into active service the next day, starting with a leg from Houston to Fort Lauderdale. Over the coming months, United expects to outfit approximately 15 mainline Boeing 737-800 planes per month with Starlink antennas.

United is offering Starlink Wi-Fi access free to United MileagePlus members. The Standard Wi-Fi option costs $8 or 1,600 miles for MileagePlus members, or $10 for everybody else. Subscriptions for frequent travelers start at $49 a month (or 7,500 miles).

In-flight Wi-Fi is all about the experience

Believe me, I want to talk about speeds and bandwidth and what a Starlink connection could mean for getting work done or being entertained in the air. But it all starts with getting connected, and too often, that experience sucks.

On my flight from Seattle to Chicago the day before my demo, United’s Standard Wi-Fi took nearly an hour to connect to any of my devices. (United uses different internet providers depending on the aircraft and operating area, and this flight was connected by satellite internet provider ViaSat.) Once the main menu page loaded, selecting most options, including «sign in» and «free messaging,» timed out with an error that there was no network connection.

That cut into my work time, but more importantly, it was incredibly frustrating. Many of us look forward to focused time on a flight to get things done without interruptions, and more frustration is the last thing we want to add to our air travel experience.

Two experiences stood out when I was on the Starlink-equipped plane. First, it operates gate-to-gate, so you can connect on your phone or tablet (laptops still need to be put away during takeoff) as soon as you get settled in your seat. After we’d landed and were taxiing back to the gate, I forgot that I was still connected through Starlink.

For almost as long as I’ve owned a cellphone, wheels-down meant it’s time to switch off Airplane mode and embrace the familiar connection of local cellular.

Second, the few sign-on steps I had to go through weren’t any more onerous than getting on a public cafe or hotel Wi-Fi network. After connecting to the United Wi-FI network, a portal window opened with a trio of screens explaining how great the new service is (you can skip them) and a field to enter my United MileagePlus account and password.

Oh, and then there’s a video ad, which is 15 seconds or less. (If you’ve been reading so far and thinking, «Wait, it can’t really be free, can it?» there’s your answer.) That ad turns out to be important: You aren’t connected until the video completes.

I was impatient and dismissed the ad on my laptop, which led to some trouble getting connected. Another journalist on the flight mentioned that he encountered the same situation, and the friendly United tech staff on the flight were curious whether the ad had played when they helped me diagnose the issue. I also emptied my browser caches and told the computer to forget the Wi-Fi network, essentially starting me from scratch.

As far as I can tell, no one else on the flight experienced this problem, but it’s safe to say there could have been some prelaunch bugs being worked out. United’s tech support won’t be on hand for regular flights, which is why one of them mentioned they were trying to iron out any points where flyers might run into difficulty.

Once connected, I could concentrate on trying to use as much bandwidth as possible and look outside occasionally since United scheduled this flight on a beautiful autumn day (instead of bringing everyone to Chicago in the dead of winter).

How Starlink Wi-Fi performed

The hardware that makes this happen is a pair of low-profile 500Mbps antennas mounted on the top of the fuselage. Unlike current units on planes offering standard Wi-Fi, the antennas are essentially exposed to communicate with the network of nearly 8,000 Starlink satellites operating in low Earth orbit (LEO), or about 350 miles in altitude.

To compare, the antenna module on a non-Starlink-equipped United plane parked at the next gate was much larger to shield its antennas, which need to adjust their angles during flight to talk to high-altitude satellites about 22,000 miles up.

In the time it takes a signal to go from a plane to high-altitude satellites, the signal can round-trip the distance between an aircraft and the Starlink satellites 70 times, according to Mara Palcisco, United Airlines vice president of engineering and reliability.

(This is also different from T-Satellite, the Starlink-powered satellite technology offered by T-Mobile. T-Satellite uses a separate collection of satellites to work with phones using a portion of the cellular spectrum.)

What does that mean in terms of the internet experience? Honestly, I’d think I was at home on my high-speed fiber internet if not for the cabin noise and the occasional tight banking turn. I streamed the (underrated, in my opinion) movie Cowboys & Aliens over Netflix on my iPad, played one of United’s available videos in a window on my MacBook Pro and watched YouTube videos on my iPhone.

Also, because this was a special flight for the press and several United employees, I initiated a video call with two colleagues. Usually, video and voice calls are not allowed — in fact, they’re illegal — and United makes a point of telling customers that they shouldn’t engage in any behavior that disturbs the people around them, including calls, listening to audio without headphones or watching media that would make others uncomfortable. You can watch a live call, but technically not talk on one, and that’s behavior flight attendants will have to enforce.

In this instance, we were encouraged to go ahead, so I had a hard-to-hear video conference with CNET managing editor Patrick Holland and senior reporter David Lumb (maybe it’s time to invest in a pair of AirPods Pro 3). The video quality was stellar — no, I’m not making a Starlink pun, I promise — even better than a few recent calls we’ve had in our respective offices. A FaceTime call with a friend was similar: clear, sharp video with no telltale streaming artifacts.

But let’s get to numbers. It’s always a nerd joy to go to Speedtest.net or run the Speedtest app and be surprised at the numbers it sends back. I consistently got around 250Mbps of download speed and anywhere from 25Mbps to 65Mbps upload speed. I saw that on all of my devices: iPhone 17 Pro, M1 iPad Pro and a 2021 MacBook Pro with an M1 Pro chip.

To put that into perspective, SpaceX says that Starlink residential internet gets up to 350Mbps download speeds, depending on location. According to an Ookla report, Starlink’s median performance is 105Mbps download, 15Mbps upload and 45ms latency. CNET senior writer Joe Supan saw similar performance when recently testing the Starlink Mini in Washington’s North Cascades mountains. (Disclosure: CNET’s parent company, Ziff Davis, also owns Ookla.)

To make what now looks like an unfair comparison, when I did get United’s standard Wi-Fi access the night before (which I paid $8 for), my speeds were 9.65Mbps down and 1.03Mbps up. Yes, those decimal points are in the correct places.

Streaming video, whether watching in-flight movies, catching up on a series on Netflix or Apple TV or watching live sports, will undoubtedly become more prevalent on flights when this level of bandwidth is available. In fact, when I chatted during the flight with Grant Milstead, United vice president of digital technology, I asked whether the in-flight videos available via United’s portal were cached on a server aboard the plane. (On my flight the previous night, I could view those even when an internet connection was elusive.)

He said that for mainline flights, which carry roughly 170 passengers, the company would still maintain those local servers for redundancy. But the regional Embraer E175 jets, the first of United’s fleet to be outfitted with the Starlink technology, rely on streamed content with no local backup. Given that the video and audio quality, from my perspective, was indistinguishable from broadband at home, that doesn’t come as a surprise.

While waiting for my trip back home (on a plane not equipped with Starlink Wi-Fi), I pondered my lasting impression of this assignment, which had me fly to Chicago, circle above Wisconsin for a couple of hours and then fly back to Seattle.

On my flight with Starlink Wi-Fi, I had uncompromised internet access. I wasn’t thinking about latency, artifacts or whether I was getting my $8 worth. I could work, watch videos, play live video games and just be bothered with any of the usual complications. And that was the best experience.