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SpaceX says Crew Dragon capsule exploded due to exotic titanium fire

Crew Dragon tests its SuperDraco-powered launch abort system in 2015. (SpaceX)

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SpaceX has announced via an official update and conference call the preliminary results of a failure investigation convened immediately after Crew Dragon capsule C201 exploded in the midst of an April 20th static fire test.

Hosted by SpaceX Vice President of Mission Assurance Hans Koenigsmann and NASA Commercial Crew Program manager Kathy Lueders, the call provided some minor additional insight beyond a fairly extensive press release issued just prior. According to the preliminary results from SpaceX’s failure investigation, Crew Dragon’s explosion was unrelated to the spacecraft’s propellant tanks, Draco maneuvering thrusters, or SuperDraco abort engines. Rather, the cause lies in a more exotic and unanticipated chemical/material interaction between a plumbing valve, liquid oxidizer, and a helium-based pressurization system.

When metal burns

According to Hans Koenigsmann, SpaceX is approximately 80% of the way through what is known as the fault tree, essentially meaning that the failure investigation is 80% complete. That additional 20% could certainly throw some curveballs but the SpaceX executive was fairly confident that the results presented on July 15th would be representative of the final conclusion.

The ultimate (likely) cause of Crew Dragon’s extremely energetic and destructive explosion centers around the spacecraft’s extensive SuperDraco/Draco plumbing and its associated pressurization system, which uses helium to keep the pressure-fed engines, propellant tanks, and feed lines around 2400 psi (16.5 megapascals). Necessarily, this method of pressurization means that there is direct contact between the pressurant (helium) and the oxidizer/fuel, thus requiring some sort of valve preventing the pressurized fluid from flowing into the pressurization system.

A detailed view of some of the Draco and SuperDraco-related plumbing used on Crew Dragon – in this case, the capsule that will now fly SpaceX’s In-Flight Abort test. (Pauline Acalin, August 2018)

During flight-proven Crew Dragon capsule C201’s April 20th static fire testing, that is reportedly exactly what happened. Over the course of ground testing, a “check valve” separating the pressurization system and oxidizer leaked what SpaceX described as a “slug” of nitrogen tetroxide oxidizer (NTO) into the helium pressurization lines. Around T-100 milliseconds to a planned ignition of the vehicle’s 8 SuperDraco abort engines, the pressurization system rapidly “initialized” (i.e. quickly pressurized the oxidizer and fuel to operational pressures, ~2400 psi).

To do this, helium is rapidly pushed through a check valve – designed with low-molecular-mass helium in mind – to physically pressurize the propellant systems. Unintentionally, the NTO that leaked ‘upstream’ through that valve effectively was taken along for the ride with the high-pressure burst of helium. In essence, picture that you crash your car, only to discover that your nice, fluffy airbag has accidentally been replaced with a bag of sand, and you might be able to visualize the unintended forces Dragon’s check valve (the metaphorical airbag) was subjected to when a “slug” of dense oxidizer was rammed into it at high speed.

Crew Dragon C201 displays its heat shield after the spacecraft’s first orbital-velocity Earth reentry, March 8th. (NASA/Cory Huston)

In itself, this sort of failure mode is not hugely surprising and SpaceX may have even been aware of some sort of check valve leak(s) and accepted what it believed to be a minor risk in order to continue the test and perhaps examine Dragon’s performance under suboptimal conditions. What SpaceX says it did not realize was just how energetic the reaction between the NTO and the check valve could be. SpaceX’s understanding is that the high-speed slug of dense NTO was traveling so fast and at such a high pressure that, by impacting the titanium check valve, it quite literally broke the valve and may have chemically ignited the metal, thus introducing a slug of burning NTO into the liberated NTO system itself – effectively a match tossed into a powder keg.

It’s unclear if the ignition came from a chemical reaction between titanium (a technically flammable metal similar to magnesium) and NTO, or if the source came from the titanium valve being smashed apart, perhaps quite literally creating a spark as metal debris violently interacted. Either way, the solution – as SpaceX perceives it – is the same: instead of a mechanical check valve (simple but still not 100% passive), the barrier between pressurant and oxidizer (as well as fuel, most likely) will be replaced with something known as a burst disk. According to Koenigsmann, only a handful (~4) of those valves exist and thus need to be replaced by burst disks, a relatively fast and easy fix.

Burst disks are single-use and inherently unreusable, but they are also completely passive and simply do not leak until subjected to a specific amount of pressure. Because they are single-use, they can’t be directly tested prior to flight, limiting some of the in-principle reliability for the sake of an extremely leak-proof barrier.

A test of one of Crew Dragon’s four ‘powerpacks’, featuring two SuperDracos and three Dracos. (SpaceX)

Ultimately, both Koenigsmann and Lueders went out of their way to avoid answering any questions about SpaceX’s Crew Dragon upcoming test and launch schedule and what sort of delays the explosion will ultimately incur. Both individuals were nevertheless upbeat and by the sound of it, delays to Crew Dragon will be far less severe relative to delays caused by a pressure vessel or engine failure. For the time being, NASA has published a tentative target of mid-November 2019 for Crew Dragon’s first crewed launch to the International Space Station, while Lueders and Koenigsmann expressed hope in a 2019 launch but refused to give a specific estimate of the odds of that occurring.

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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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SpaceX just launched a secret payload from California

SpaceX launched a classified Space Force mission from Vandenberg, revealing almost nothing about its payload.

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Space Force officials say the Falcon 9 booster pictured here in SpaceX's rocket factory will have to wait a few months longer for its launch debut. (SpaceX)

SpaceX launched a classified Falcon 9 mission for the U.S. Space Force from Vandenberg Space Force Base on Saturday night, and the government released almost nothing about what was on board. The mission, designated USSF-366, lifted off from Space Launch Complex 4E with a window that opened at 9:52 p.m. ET and ran into the early hours of Sunday, according to SpaceX’s own mission page, which described the payload only as classified. SpaceX confirmed the launch on its X account and pointed viewers to a livestream that began roughly ten minutes before liftoff.


The lack of detail did not stop analysts from filling in the blanks. Independent tracking of the rocket’s stage drop zones matched the pattern SpaceX has used on previous Starlink Group 15 missions, according to reporting from Outer Space Today, which pointed to Starshield as the likely payload rather than a one off government satellite. Starshield is SpaceX’s national security product, a version of the Starlink satellite bus built to Pentagon specifications for earth observation, communications and hosted payloads. Unlike consumer Starlink, government agencies do not have to disclose what Starshield satellites are actually doing once they reach orbit.

USSF-366 is the latest entry in a steady flow of classified and semi classified work between SpaceX and the Space Force. The company picked up a $178.5 million task order in April to launch missile tracking satellites for the Space Development Agency, as Teslarati reported at the time, and followed that in July with a $1.6 billion award covering 18 more Falcon 9 missions from Vandenberg through the end of 2027, also detailed by Teslarati. Add those contracts up and SpaceX’s Pentagon business for 2026 alone tops $8 billion.

SpaceX scores another massive Pentagon deal to support military satellites

The Falcon 9 that flew Saturday landed back near the launch site, producing the sonic booms that have become routine for residents near Vandenberg. What is less routine is how little the public will likely ever learn about what the rocket carried. SpaceX and the Space Force have not confirmed the Starshield connection, and government satellite programs built on commercial buses rarely get identified beyond a mission number and a general orbit. For a company that live streams almost everything else it does, from Starship test flights to Optimus robot demos, USSF-366 is a reminder that some of SpaceX’s busiest work now happens entirely out of public view.

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Tesla V2L adapter for Model Y stirs up a new complaint among owners

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Credit: Tesla

On Friday, Tesla launched the Outlet Adapter that enabled Vehicle-to-Load (V2L) energy transfer, meaning owners could essentially utilize their cars as a power source for things like laptops, electric grills, or string lights.

However, even owners of some of the newest builds of the Model Y are finding out that their cars are not compatible with the new $80 accessory, stirring up a new complaint among members of the community.

Tesla launches V2L Outlet Adapter for Premium Model Y in the U.S.

Upon the release of the Outlet Adapter on Friday, I signed into my Tesla account to order the accessory. However, I was met with the dreaded “This product is not compatible with your 2026 Model Y” message at the bottom of the screen.

Some said their accounts also displayed the same message, but they ordered anyway. However, they might be surprised to find that this is no mistake; some of the newest Model Ys do not have the appropriate Power Conversion System (PCS). Mine, which was ordered on this day last year and delivered on August 31, has the old 48A, single-phase PCS.

Vehicles with the new, two-piece PCS are able to utilize V2L features on their cars:

Obviously, it’s disappointing. Many owners have taken delivery this year and still can not utilize the Outlet Adapter because their cars feature the old PCS:

It looks like if you have one of these older PCS units, you can upgrade, but the parts alone are $1,750, and that’s before Tesla adds labor for installing. It is honestly more logical to get some kind of portable power supply or power station at that point.

It is great that Tesla has enabled V2L for Model Y vehicles, but it is also unfortunate that vehicles that are less than one year old are not able to take advantage of this awesome new feature.

With that being said, it truly is a first-world problem; can you really complain when Full Self-Driving is available, maintenance is incredibly inexpensive, and the car has been so good through a year of ownership?

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Tesla launches V2L Outlet Adapter for Premium Model Y in the U.S.

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Credit: Tesla

Tesla has launched a new Vehicle-to-Load (V2L) Outlet Adapter for Premium Model Y vehicles in the United States, meaning you can now power devices like laptops or light strings with your vehicle’s battery.

It appears the capability will be available for any Model Y Premium trim, including those that were purchased prior to the Adapter being launched. It will also only impact Juniper Model Y vehicles, so the first-gen owners will unfortunately not have access to this capability.

If your Model Y was purchased before Tesla renamed the trim levels to “Premium” and “Standard,” it does not seem to be compatible. My Model Y is technically a Premium build, as it is the Long Range All-Wheel-Drive. However, Tesla says it is not compatible with my vehicle.

For $80, you can now utilize your car as a portable charger for small appliances or devices. This is perfect for things like tailgates, concerts, or camping, as you can now plug in devices that you might use. Those string lights for camping? That laptop for the other games that are on at the tailgate?

They’ll both utilize energy from your Tesla’s battery to be powered. This is the first time Tesla has expanded the capability to vehicles outside of the Model Y Performance and Cybertruck. However, this feature has been highly requested by owners for an extended period of time.

Tesla launched the Outlet Adapter in China last year:

Tesla China rolls out Model Y L V2L adapter, and it’s free for early owners

You will need the Mobile Connector to operate the Outlet Adapter: the Outlet Adapter will plug into the main housing of the Mobile Connector, where the appropriate adapter to charge your vehicle will plug in.

It is rated for 120 volts and 20 amps, and has a max power rating of 2.4kW.

You can buy it here from Tesla for $80.

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