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NASA scrubs first SLS Moon rocket launch attempt

A beautiful start to an unfortunately unfruitful day. (Richard Angle)

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4 years ago

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NASA has scrubbed the first attempted launch of its Space Launch System (SLS) Moon rocket after running into multiple issues, one of which could not be solved in time.

The delay is bad news for the tens to hundreds of thousands of tourists who traveled to Cape Canaveral, Florida to witness the launch in person. Worse, by NASA’s own implicit admission, there’s a good chance the main problem SLS encountered could have already been dealt with and rectified in advance of the launch attempt if the space agency had finished testing the rocket earlier this summer.

Ultimately, that omission turned the first SLS launch attempt into more of a continuation of the rocket’s first four wet dress rehearsal (WDR) attempts, none of which ended as expected. NASA engineers will now have to decide how to proceed and whether the SLS rocket can be made ready in time for another launch attempt on September 2nd or 5th. If not, the next opportunity could be weeks away.

As far as SLS test operations go, the August 28/29th launch attempt was fairly ordinary, with the rocket running into multiple issues – a few minor, a few significant, and one identical to a previous problem. The first problem – a hydrogen leak near the SLS rocket’s base – came after a risk of lightning delayed the start of propellant loading by more than an hour. A very similar, if not identical, hydrogen fuel leak had already occurred during official wet dress rehearsal testing in April and July.

That leak was fixed on the fly by properly chilling all related systems, and propellant loading was eventually completed – albeit a few hours late thanks to inclement weather. Shortly after, there were reports of a crack that needed careful analysis. Only later did NASA specify that the suspected crack was in the rocket’s foam insulation rather than its structures, the latter of which could have been a catastrophic problem.

Around the same time, the true showstopper of the day occurred when NASA attempted to chill the SLS Core Stage’s four RS-25 engines, all of which flew several times aboard reusable Space Shuttle orbiters. Three engines performed (mostly) as expected, flowing a bit of liquid hydrogen fuel to cool themselves down, but one – engine #3 – was never able to make progress toward the optimal temperature needed for ignition (~5°C/~41°F). After hours of remote troubleshooting attempts, no progress had been made, and NASA ultimately decided to scrub the launch attempt at T-40 minutes to liftoff.

Over the course of four separate wet dress rehearsal attempts in April and June 2022, NASA was never able to test the core stage’s engine chill capabilities. In a post-scrub press conference, Jim Free – NASA’s Associate Administrator of the Exploration Systems Development Division – revealed that all four engines were warmer than intended, further confirming that skipping a fully nominal wet dress rehearsal was likely a mistake. Clear and present evidence aside, Free stated that he and other executives still believed skipping that test was the right decision, claiming that ending explicit WDR testing reduced the number of times the rocket needed to be moved on its transporter.

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Making the situation even harder to explain, Artemis I Mission Manager Mike Sarafin revealed in the conference Q&A that Boeing had changed the design of parts of the SLS engine chill (bleed) system after the Core Stage finally conducted a nominal static fire test at Mississippi’s Stennis Space Center. Completed in March 2021, the SLS rocket then sat inside NASA’s Kennedy Space Center, Florida Vehicle Assembly Building (VAB) for a full year before attempting its first wet dress rehearsal tests at the launch pad.

The first round of three WDRs were not as smooth as NASA expected and instead uncovered three relatively small issues: a hydrogen leak, a single faulty upper stage valve, and problems with a ground supply of nitrogen gas. Those small issues led NASA to roll SLS back to the VAB for repairs, incurring a minimum multi-week delay that stretched into two months. SLS also failed to complete a fourth WDR attempt in July 2022, but NASA decided to overlook the rocket parts and phases of preflight operations that were never actually tested as planned, one of which was the engine chill system.

If NASA cannot fix the RS-25 chill system within the next few days, it will be forced to roll the entire rocket and mobile launch platform back to the VAB to – at a minimum – replace its flight termination system (FTS). The US Eastern Range requires that all rocket FTS systems be tested no more than 15 days before launch, and NASA was able to secure special permission for a gap of up to 25 days. However, because Boeing’s Core Stage design places the FTS system in a location that is reportedly inaccessible at the pad, the entire SLS rocket will need to roll back to the VAB to have its FTS systems “retested” after that period.

As a result, NASA’s SLS launch debut will be delayed by several weeks (at best) if it can’t recycle for another attempt on September 2nd or 5th. The next window runs from September 20th to October 4th, but the SLS rocket took 10 days to go from its latest rollout to first launch attempt – a figure that doesn’t include the time required to remove the rocket from the pad, roll it back to the VAB, and conduct any necessary repairs or tests while back in the bay. If NASA can’t fix the engine problem at the pad by September 3rd or 4th, the true delay could be more like 4-6 weeks.

With any luck, that won’t happen, but it’s clear that a lot of stress and discomfort could have been avoided if NASA had gone into its first launch attempt knowing that its SLS rocket was truly ready.

(Richard Angle)
(Richard Angle)
(Richard Angle)
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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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1 hour 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

3 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

11 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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