Connect with us

News

SpaceX’s Starship explosion explained by Elon Musk

The burning wreckage of Starship SN4, May 29th. (SPadre)

Published

5 years ago

on

Shortly after a briefing following SpaceX’s flawless astronaut launch debut, CEO Elon Musk casually revealed the best explanation yet for why a Starship prototype violently exploded during testing on May 29th.

On that fated Saturday, SpaceX successfully completed the fifth static fire of a Raptor engine installed on a full-scale Starship prototype, preceded by about an hour and a half of vehicle checks and propellant loading. Unfortunately, around a minute after Raptor shut down, what was quickly identified as liquid methane began spurting out of a specific section at the base of Starship, rapidly creating a massive cloud as the cryogenic propellant boiled and turned into gas. The specific source is unclear but moments later, something under Starship SN4 provided the shock or spark needed to ignite the expanding fire hazard, producing a spectacularly large and violent explosion.

Unsurprisingly, the accidental fuel-air explosion that was created obliterated Starship SN4 in the blink of an eye, shredding its lower (liquid oxygen) tank into steel confetti and immediately breaching the upper (liquid methane) tank, which fell to the ground and subsequently exploded again. The launch mount Starship was staged on was also damaged beyond repair and has been fully dismantled and scrapped in the two days since the anomaly. Thankfully, however, SpaceX already has replacement mounts and ships well on their way to carrying Starship SN4’s torch forward and Elon Musk already seems to understand what caused the prototype’s demise.

Shortly after a post-launch briefing celebrating and discussing SpaceX’s inaugural astronaut launch on May 30th, Reuters reporter Joey Roulette was able to ask Musk about Starship SN4’s spectacular demise the day prior. The SpaceX CEO was quoted saying that “what we thought was going to be a minor test of a quick disconnect ended up being a big problem”, confirming suspicions based on careful analysis of public views of the explosion that it was caused by issues with Starship’s ground support equipment (GSE).

Starhopper’s quick-disconnect umbilical panel is pictured here in May 2019. Starship SN4 used a similar mechanism, although the plumbing is now located inside the vehicle’s circumference. (NASASpaceflight – bocachicagal)

In Musk’s statement, “quick disconnect” (QD) refers to an umbilical port that connects a launch vehicle to GSE, enabling the loading and offloading of propellant and fluids, clamping down the rocket, and providing a wired telemetry and communications link for ground controllers. QDs must perform all those tasks while also being able to rapidly release and disconnect, allowing the rocket to lift off while still protecting its sensitive ports for ease of reuse.

In theory, Starship’s quick-disconnect umbilical panel is even more complex, as it will have to simultaneously enable the ship to be fueled and controlled while sitting on top of a Super Heavy booster and permit in-orbit docking and refueling. Given that Starships are currently being tested independently on spartan launch mounts, it’s unclear if the current generation of prototypes has been outfitted with advanced QD panels. More likely, Musk was referring to a test of a less advanced QD panel similar to the rough version used on Starhopper last year, and SpaceX simply wanted to test its ability to disconnect and reconnect to Starship on command.

Advertisement
SpaceX’s existing Starship launch mount was heavily damaged by SN4’s explosion and has since been fully dismantled. (NASASpaceflight – bocachicagal)
Starship SN4’s remains have already been cleared from the pad. (NASASpaceflight – bocachicagal)

If that’s the case, the likeliest explanation for SN4’s explosion is that that quick disconnect was unable to fully reconnect after the test, resulting in a leak from the liquid methane port when SpaceX began to detank the rocket. Instead of the highly-pressurized fluid flowing smoothly back to ground storage tanks, the liquid methane sprayed wildly, akin to the effect one might observe when attempting to block off an active water source with an open palm.

Work on a second launch mount was already ongoing when Starship SN4 exploded on May 29th. (NASASpaceflight – bocachicagal)
Starship SN5 and SN6 are simultaneously being assembled in SpaceX’s new vertical assembly building (VAB). (NASASpaceflight – bocachicagal)

Compared to the many possible ways a fueled Starship could fail, a propellant leak started by a faulty umbilical panel is about as convenient as they come. Starship SN4 may have been violently destroyed as a result, turning a relatively small error into exceptionally painful lesson but SpaceX has already had some success building full-scale prototypes at an almost unbelievably low cost – likely less than $10M apiece. Starship SN5 appears to be just shy of ready to take SN4’s place on the launch mount, although SpaceX will have to build an entirely new launch mount before it can resume testing.

At the same time, Starship SN5’s successor – SN6 – is just one stacking event away from reaching a level of completion similar to SN4 and SN5. All told, Starship SN4’s demise is just another part of the process of developing a new kind of rocket by building and testing hardware – failure can be a valuable tool when managed properly. Based on past observations, SpaceX could be ready to continue testing (and hopefully flying) Starship prototypes before the end of the month.

Check out Teslarati’s Marketplace! We offer Tesla accessories, including for the Tesla Cybertruck and Tesla Model 3.

Related Topics:

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.

Advertisement
Comments

Elon Musk

Elon Musk reveals when SpaceX will perform first-ever Starship catch

“Starship catch is probably flight 13 to 15, depending on how well V3 flights go,” Musk said.

Published

3 hours ago

on

August 28, 2025

By

Credit: SpaceX

Elon Musk revealed when SpaceX would perform the first-ever catch attempt of Starship, its massive rocket that will one day take life to other planets.

On Tuesday, Starship aced its tenth test flight as SpaceX was able to complete each of its mission objectives, including a splashdown of the Super Heavy Booster in the Gulf, the deployment of eight Starlink simulators, and another splashdown of the ship in the Indian Ocean.

It was the first launch that featured a payload deployment:

SpaceX Starship Flight 10 was so successful, it’s breaking the anti-Musk narrative

SpaceX was transparent that it would not attempt to catch the Super Heavy Booster, something it has done on three previous occasions: Flight 5 on October 13, 2024, Flight 7 on January 16, and Flight 8 on March 6.

This time, it was not attempting to do so. However, there are bigger plans for the future, and Musk detailed them in a recent post on X, where he discussed SpaceX’s plans to catch Starship, which would be a monumental accomplishment.

Musk said the most likely opportunities for SpaceX to catch Starship itself would be Flight 13, Flight 14, and Flight 15, but it depends on “how well the V3 flights go.”

The Starship launched with Flight 10 was a V2, which is the same size as the subsequent V3 rocket but has a smaller payload-to-orbit rating and is less powerful in terms of initial thrust and booster thrust. Musk said there is only one more V2 rocket left to launch.

V3 will be the version flown through 2026, as V4, which will be the most capable Starship build SpaceX manufactures, is likely to be the first company ship to carry humans to space.

Musk said that SpaceX planned to “hopefully” attempt a catch of Starship in 2025. However, it appears that this will likely be pushed back to 2026 due to timing.

SpaceX will take Starship catch one step further very soon, Elon Musk confirms

SpaceX would need to launch the 11th and 12th test flights by the end of the year in order to get to Musk’s expected first catch attempt of Flight 13. It’s not unheard of, but the company will need to accelerate its launch rate as it has only had three test flights this year.

Continue Reading

News

Tesla Robotaxi rival Waymo confirms massive fleet expansion in Bay Area

New data from the California Public Utilities Commission (CPUC) said Waymo had 1,429 vehicles operating in California, and 875 of them were “associated with a terminal in San Francisco,” according to The SF Examiner.

Published

5 hours ago

on

August 28, 2025

By

Credit: Uber

Tesla Robotaxi rival Waymo has confirmed that it has expanded its fleet of driverless ride-sharing vehicles in the Bay Area of California massively since its last public disclosure.

It is perhaps one of the most important metrics in the race for autonomous supremacy, along with overall service area. Tesla has seemed to focus on the latter, while expanding its fleet slowly to maintain safety.

Waymo, on the other hand, is bringing its fleet size across the country to significant levels. In March, it told The SF Examiner that there were over 300 Waymos in service in the San Francisco area, which was not a significant increase from the 250 vehicles on the road it reported in August 2023.

In May, the company said in a press release that it had more than 1,500 self-driving Waymos operating nationwide. More than 600 were in the San Francisco area.

Tesla analyst compares Robotaxi to Waymo: ‘The contrast was clear’

However, new data from the California Public Utilities Commission (CPUC) said Waymo had 1,429 vehicles operating in California, and 875 of them were “associated with a terminal in San Francisco,” according to The SF Examiner.

CPUC data from March 2025 indicated that there were a total of 1,087 Waymo vehicles in California, with 762 located in San Francisco. Some were test vehicles, others were deployed to operate as ride-sharing vehicles.

The company’s August update also said that it deploys more than 2,000 commercial vehicles in the United States. That number was 1,500 in May. There are also roughly 400 in Phoenix and 500 in Los Angeles.

While Waymo has done a good job of expanding its fleet, it has also been able to expand its footprint in the various cities it is operating in.

Most recently, it grew its geofence in Austin, Texas, to 90 square miles. This outpaced Tesla for a short period before the company expanded its Robotaxi service area earlier this week to roughly 170 square miles.

Tesla one-ups Waymo once again with latest Robotaxi expansion in Austin

The two companies have drastically different approaches to self-driving, as Waymo utilizes LiDAR, while Tesla relies solely on cameras for its suite. Tesla CEO Elon Musk has made no mistake about which he believes to be the superior solution to autonomy.

Continue Reading

News

Tesla launches Full Self-Driving in a new region

Today, Tesla launched Full Self-Driving in Australia for purchase by car buyers for $10,100, according to Aussie automotive blog Man of Many, which tried out the suite earlier this week.

Published

6 hours ago

on

August 28, 2025

By

Credit: Tesla

Tesla has launched its Full Self-Driving suite in a new region, marking a significant step in the company’s progress to expand its driver assistance suite on a global scale.

It is also the first time Tesla has launched FSD in a right-hand-drive market.

Today, Tesla launched Full Self-Driving in Australia for purchase by car buyers for $10,100, according to Aussie automotive blog Man of Many, which tried out the suite earlier this week.

Previously, Basic and Enhanced Autopilot suites were available, but the FSD capability now adds Traffic Light and Stop Sign Control, along with all the features of the previous two Autopilot suites.

It is the first time Tesla has launched the suite by name in a region outside of North America. In China, Tesla has “City Autopilot,” as it was not permitted to use the Full Self-Driving label for regulatory reasons.

However, Tesla still lists Full Self-Driving (Supervised) as available in the U.S., Canada, China, Mexico, and Puerto Rico.

The company teased the launch of the suite in Australia earlier this week, and it appeared to have been released to select media members in the region earlier this week:

Tesla FSD upcoming Australia release seemingly teased bv media

The rollout of Full Self-Driving in the Australian market will occur in stages, as Model 3 and Model Y vehicles with Hardware 4 will receive the first batch of FSD rollouts in the region.

TechAU also reported that “the initial deployment of FSDs in Australia will roll out to a select number of people outside the company, these people are being invited into Tesla’s Early Access Program.”

Additionally, the company reportedly said it is “very close” to unlocking FSD in customer cars:

Each new Tesla sold will also come with a 30-day free trial of the suite.

Australia is the sixth country to officially have Full Self-Driving available to them, following the United States, Canada, China, Mexico, and Puerto Rico.

Here’s the first look at the suite operating in Australia:

Continue Reading

Trending