Eksplozja rakiety Falcon 9 (1.09.2016)

[astropl]

SpaceX podało, co poniżej:

October 28, 4:00pm EDT

The Accident Investigation Team continues to make progress in examining the anomaly on September 1 that led to the loss of a Falcon 9 and its payload at Launch Complex 40 (LC-40), Cape Canaveral Air Force Station, Florida.

Since the incident, investigators from SpaceX, the FAA, NASA, the US Air Force and industry experts have been working methodically through an extensive fault tree to investigate all plausible causes. As part of this, we have conducted tests at our facility in McGregor, Texas, attempting to replicate as closely as possible the conditions that may have led to the mishap.

The investigation team has made significant progress on the fault tree. Previously, we announced the investigation was focusing on a breach in the cryogenic helium system of the second stage liquid oxygen tank. The root cause of the breach has not yet been confirmed, but attention has continued to narrow to one of the three composite overwrapped pressure vessels (COPVs) inside the LOX tank. Through extensive testing in Texas, SpaceX has shown that it can re-create a COPV failure entirely through helium loading conditions. These conditions are mainly affected by the temperature and pressure of the helium being loaded.

SpaceX’s efforts are now focused on two areas – finding the exact root cause, and developing improved helium loading conditions that allow SpaceX to reliably load Falcon 9. With the advanced state of the investigation, we also plan to resume stage testing in Texas in the coming days, while continuing to focus on completion of the investigation. This is an important milestone on the path to returning to flight.

Pending the results of the investigation, we continue to work towards returning to flight before the end of the year. Our launch sites at Kennedy Space Center, Florida, and Vandenberg Air Force Base, California, remain on track to be operational in this timeframe.

[kanarkusmaximus]

Bardzo ciekawe wiadomości! Przede wszystkim że udało się im odtworzyć uszkodzenie zbiornika helu.

[kanarkusmaximus]

Podsumowując, jaka jest obecnie główna (prawie końcowa) teoria co do eksplozji?

Wewnątrz zbiornika LOX był zbiornik kompozytowy helu. Podczas tankowania schłodzonego LOX doszło do zestalenia pewnej ilości tlenu do "lodu tlenowego" przy okolicach zbiornika helu. To spowodowało pęknięcie zbiornika helu, co doprowadziło do ... właśnie - czego? ... pęknięcia zbiornika tlenu i w konsekwencji bum?

Czy może ktoś mnie poprawić?

[NilQ]

Wydaje mi się, że ten komentarz może być pomocny:

The leading theory is that liquid oxygen got trapped between layers of Carbon overwrap when filling the LOX tank. They then filled the COPVs with Helium, which expanded and actually cooled the COPV down. This solidified the once liquid oxygen trapped between the layers of Carbon. The COPVs continued to be filled with Helium, so they expanded, and crushed the now solid oxygen between layers of Carbon, igniting them inside the LOX tank.

[kanarkusmaximus]

Czyli zestalenie się lodu pomiędzy warstwami włókna węglowego? Nieźle. Ten zapłon od czego mógł pochodzić?

[NilQ]

I w końcu długo oczekiwana aktualizacja od SpaceX wyjaśniająca przyczynę katastrofy:

January 2, 2017, 9:00am EST

Over the past four months, officials at the Federal Aviation Administration (FAA), the U.S. Air Force (USAF), the National Aeronautics and Space Administration (NASA), the National Transportation Safety Board (NTSB), along with several industry experts, have collaborated with SpaceX on a rigorous investigation to determine the cause of the anomaly that occurred September 1 at Space Launch Complex 40 (SLC-40) at Cape Canaveral Air Force Station in Florida. This investigation team was established according to SpaceX's accident investigation plan as approved by the FAA. As the primary federal licensing body, the FAA provided oversight and coordination for the investigation.

Investigators scoured more than 3,000 channels of video and telemetry data covering a very brief timeline of events – there were just 93 milliseconds from the first sign of anomalous data to the loss of the second stage, followed by loss of the vehicle. Because the failure occurred on the ground, investigators were also able to review umbilical data, ground-based video, and physical debris. To validate investigation analysis and findings, SpaceX conducted a wide range of tests at its facilities in Hawthorne, California and McGregor, Texas.

The accident investigation team worked systematically through an extensive fault tree analysis and concluded that one of the three composite overwrapped pressure vessels (COPVs) inside the second stage liquid oxygen (LOX) tank failed. Specifically, the investigation team concluded the failure was likely due to the accumulation of oxygen between the COPV liner and overwrap in a void or a buckle in the liner, leading to ignition and the subsequent failure of the COPV.

Each stage of Falcon 9 uses COPVs to store cold helium which is used to maintain tank pressure, and each COPV consists of an aluminum inner liner with a carbon overwrap. The recovered COPVs showed buckles in their liners. Although buckles were not shown to burst a COPV on their own, investigators concluded that super chilled LOX can pool in these buckles under the overwrap. When pressurized, oxygen pooled in this buckle can become trapped; in turn, breaking fibers or friction can ignite the oxygen in the overwrap, causing the COPV to fail. In addition, investigators determined that the loading temperature of the helium was cold enough to create solid oxygen (SOX), which exacerbates the possibility of oxygen becoming trapped as well as the likelihood of friction ignition.

The investigation team identified several credible causes for the COPV failure, all of which involve accumulation of super chilled LOX or SOX in buckles under the overwrap. The corrective actions address all credible causes and focus on changes which avoid the conditions that led to these credible causes. In the short term, this entails changing the COPV configuration to allow warmer temperature helium to be loaded, as well as returning helium loading operations to a prior flight proven configuration based on operations used in over 700 successful COPV loads. In the long term, SpaceX will implement design changes to the COPVs to prevent buckles altogether, which will allow for faster loading operations.​

SpaceX is targeting return to flight from Vandenberg's Space Launch Complex 4E (SLC-4E) with the Iridium NEXT launch on January 8. SpaceX greatly appreciates the support of our customers and partners throughout this process, and we look forward to fulfilling our manifest in 2017 and beyond.

http://www.spacex.com/news/2016/09/01/anomaly-updates

Czyli to, o czym mówiło się od dłuższego czasu - nagromadzenie się zestalonego lodu pomiędzy włóknami zbiornika COPV (pomiędzy wewnętrzną ścianką z aluminium a jej obudową z carbonu). Przy zwiększaniu ciśnienia doszło do tarcia lub przerwania włókien węglowych, które spowodowały pożar tlenu. Na szybko problem rozwiązali powracając do poprzednich procedur tankowania (cieplejszy hel), w przyszłości muszą wprowadzić modyfikacje w butlach COPV.

[Orionid]

Chronologicznie to kiedy ostatnio wybuchła rakieta przed startem? To chyba niezbyt często się zdarza, jak już są fajerwerki to na ogół podczas startu lub lotu?

Ostatnio to brazylijska VLS-1 w 2003.

A nie irański Safir-1B w 2012 ?

[kanarkusmaximus]

My tu gadu gadu, a wczoraj minęły dwa lata od wybuchu rakiety. Patrząc na prace SpaceX w kolejnych miesiącach: utrata tej rakiety i satelity AMOS-6 z pewnością dała dużo firmie, która się nauczyła z tej porażki.

[Orionid]

Niedługo minie 10 lat od pamiętnej eksplozji na wyrzutni.
Wspomnienia pracowników SpaceX obfitujące w interesujące szczegóły.

How long will it take to rebuild Blue Origin’s launch pad? We asked some SpaceX vets.
Eric Berger – 3 cze 2026 12:00

“Everyone is in a place where it’s no fun to be there.”

(...) Koenigsmann was SpaceX’s vice president of build and flight reliability at the time, and his team faced the challenge of identifying the failure in the upper stage of the Falcon 9 rocket that caused it to explode during a relatively benign part of the fueling process.

This involved a weekslong search of the wetlands surrounding the launch site at Cape Canaveral for pieces of the booster. The idea was that the components farthest from the pad were nearest the most energetic part of the explosion. Ultimately, the investigative team narrowed in on the complex failure of the lining of a pressure vessel in the upper stage. (...)

After the AMOS-6 failure, SpaceX was also without an active launch pad for the Falcon 9 rocket. Nearest to readiness was an existing pad at Vandenberg Air Force Base in California, which was undergoing upgrades to support the “Full Thrust” variant of the Falcon 9 rocket, which used densified propellant. This is where the Falcon 9 returned to flight, less than five months later, in January 2017.

SpaceX then focused on completing modifications to Launch Complex 39A at Kennedy Space Center, which it had leased from NASA. The Falcon 9 rocket launched from here in February 2017. (...)

According to Muratore, SpaceX was not allowed to begin reconstruction work at the launch pad until January 2017. The delay stemmed from the ongoing investigation, which included a grid-by-grid examination of debris, cataloging recovered materials, and launch site remediation. Muratore and other SpaceX engineers spent these four months redesigning the launch pad. (...)

The search for debris lasted from shortly after the explosion until early October, when efforts had to be abandoned due to the approach of the powerful Hurricane Matthew. (...)

When it began rebuilding SLC-40, SpaceX had some advantages, Muratore said. The company had great teams coming from its pads at Kennedy Space Center and Vandenberg—not just the engineers, but also welders and other laborers who work directly on the infrastructure. This allowed SpaceX—a company already known for moving rapidly—to power through the SLC-40 rebuild.

Still, it took a while, with the first Falcon 9 rocket not launching from a rebuilt SLC-40 pad until December 2017. Including site remediation, SpaceX went from the AMOS-6 failure to a new launch in 15.5 months. The actual construction part, following remediation and design, required 11 months. (...)
https://arstechnica.com/space/2026/06/how-long-will-it-take-to-rebuild-blue-origins-launch-pad-we-asked-some-spacex-vets/