News
SpaceX says Crew Dragon capsule exploded due to exotic titanium fire
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.
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.
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.
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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Elon Musk
SpaceX targets 150Mbps per user for upgraded Starlink Direct-to-Cell
If achieved, the 150Mbps goal would represent a significant jump from the current performance of Starlink Direct-to-Cell.
SpaceX is targeting peak download speeds of 150Mbps per user for its next-generation Direct-to-Cell Starlink service. The update was shared by SpaceX Spectrum & Regulatory Affairs Lead Udrivolf Pica during the International Telecommunication Union’s Space Connect conference.
“We are aiming at peak speeds of 150Mbps per user,” Pica said during the conference. “So something incredible if you think about the link budgets from space to the mobile phone.”
If achieved, the 150Mbps goal would represent a significant jump from the current performance of Starlink Direct-to-Cell.
Today, SpaceX’s cellular Starlink service, offered in partnership with T-Mobile under the T-Satellite brand, provides speeds of roughly 4Mbps per user. The service is designed primarily for texts, low-resolution video calls, and select apps in locations that traditionally have no cellular service.
By comparison, Ookla data shows median 5G download speeds of approximately 309Mbps for T-Mobile and 172Mbps for AT&T in the United States, as noted in a PCMag report. While 150Mbps would still trail the fastest terrestrial 5G networks, it would place satellite-to-phone broadband much closer to conventional carrier performance, even in remote areas.
Pica indicated that the upgraded system would support “video, voice, and data services, clearly,” moving beyond emergency connectivity and basic messaging use cases.
To reach that target, SpaceX plans to upgrade its existing Starlink Direct-to-Cell satellites and add significant new capacity. The company recently acquired access to radio spectrum from EchoStar, which Pica described as key to expanding throughput.
“More spectrum means a bigger pipeline, and this means that we can expand what we can do with partners. We can expand the quality of service. And again, we can do cellular broadband basically, cellular broadband use cases, like AI or daily connectivity needs,” he stated.
SpaceX has also requested regulatory approval to deploy 15,000 additional Direct-to-Cell satellites, beyond the roughly 650 currently supporting the system. The upgraded architecture is expected to begin rolling out in late 2027.
News
Tesla seeks approval to test FSD Supervised in new Swedish city
Tesla has applied to conduct local Full Self-Driving (Supervised) testing in the city of Jönköping, Sweden.
Tesla has applied to conduct local Full Self-Driving (Supervised) testing in the city of Jönköping, Sweden.
As per local outlet Jönköpings-Posten, Tesla has contacted the municipality with a request to begin FSD (Supervised) tests in the city. The company has already received approval to test its Full Self-Driving (Supervised) software in several Swedish municipalities, as well as on the national road network.
Sofia Bennerstål, Tesla’s Head of Public Policy for Northern Europe, confirmed that an application has been submitted for FSD’s potential tests in Jönköping.
“I can confirm that we have submitted an application, but I cannot say much more about it,” Bennerstål told the news outlet. She also stated that Tesla is “satisfied with the tests” in the region so far.
The planned tests in Jönköping would involve a limited number of Tesla-owned vehicles. Trained Tesla safety drivers would remain behind the wheel and be prepared to intervene if necessary.
Tesla previously began testing in Nacka municipality after receiving local approval. At the time, the company stated that cooperation between authorities, municipalities, and industry enables technological progress and helps integrate future transport systems into real-world traffic conditions, as noted in an Allt Om Elbil report.
If approved, Jönköping would become the latest Swedish municipality to allow local Full Self-Driving (Supervised) testing.
Tesla’s Swedish testing program is part of the company’s efforts to validate its supervised autonomous driving software in everyday traffic environments. Municipal approvals allow Tesla to gather data in urban settings that include roundabouts, complex intersections, and mixed traffic conditions.
Sweden has become an increasingly active testing ground for Tesla’s driver-assistance software in Europe, with regulatory coordination between local authorities and national agencies enabling structured pilot programs.
Elon Musk
Microsoft partners with Starlink to expand rural internet access worldwide
The update was shared ahead of Mobile World Congress.
Microsoft has announced a new collaboration with Starlink as part of its expanding digital access strategy, following the company’s claim that it has extended internet connectivity coverage to more than 299 million people worldwide.
The update was shared ahead of Mobile World Congress, where Microsoft detailed how it surpassed its original goal of bringing internet access to 250 million people by the end of 2025.
In a blog post, Microsoft confirmed that it is now working with Starlink to expand connectivity in rural and hard-to-reach regions.
“Through our collaboration with Starlink, Microsoft is combining low-Earth orbit satellite connectivity with community-based deployment models and local ecosystem partnerships,” the company wrote.
The partnership is designed to complement Microsoft’s existing work with local internet providers and infrastructure companies across Africa, Latin America, and India, among other areas. Microsoft noted that traditional infrastructure alone cannot meet demand in some regions, making low-Earth orbit satellite connectivity an important addition.
Kenya was cited as an early example. Working with Starlink and local provider Mawingu Networks, Microsoft is supporting connectivity for 450 community hubs in rural and underserved areas. These hubs include farmer cooperatives, aggregation centers, and digital access facilities intended to support agricultural productivity and AI-enabled services.
Microsoft stated that 2.2 billion people globally remain offline, and that connectivity gaps risk widening as AI adoption accelerates.
Starlink’s expanding constellation, now numbering more than 9,700 satellites in orbit, provides near-global coverage, making it one of the few systems capable of delivering broadband to remote regions without relying on terrestrial infrastructure.
Starlink is expected to grow even more in the coming years as well, especially as SpaceX transitions its fleet to Starship, which is capable of carrying significantly larger payloads compared to its current workhorse, the Falcon 9.
SpaceX targets 150Mbps per user for upgraded Starlink Direct-to-Cell
Tesla seeks approval to test FSD Supervised in new Swedish city
