Incident: SpaceX Crew Dragon Capsule Explosion Due to Pressurization System Leak

Published Date: 2019-07-15

Postmortem Analysis
Timeline 1. The software failure incident involving the SpaceX Crew Dragon capsule exploding during a ground test at Cape Canaveral in Florida happened in April 2019 as mentioned in Article 86995.
System 1. Crew Dragon's pressurization system [86995]
Responsible Organization 1. SpaceX [86995]
Impacted Organization 1. SpaceX [86995]
Software Causes unknown
Non-software Causes 1. A leak in the spacecraft's pressurization system allowed a liquid oxidizer (nitrogen tetroxide, NTO) to make contact with a titanium valve, leading to an explosive reaction [86995].
Impacts 1. The software failure incident involving the SpaceX Crew Dragon capsule explosion during a ground test at Cape Canaveral in Florida led to the destruction of the spacecraft due to a leak causing a surprising chemical reaction [86995].
Preventions 1. Implementing more rigorous testing procedures for the spacecraft's pressurization system to detect potential leaks before they lead to catastrophic reactions [86995]. 2. Conducting thorough risk assessments and simulations to identify possible unexpected chemical reactions between materials used in the spacecraft components [86995]. 3. Enhancing the design of the spacecraft's pressurization system to prevent leaks and ensure proper containment of hazardous substances [86995].
Fixes 1. Replace the valves with burst disks that seal more completely to mitigate the risk [86995].
References 1. SpaceX 2. NASA 3. Federal Aviation Administration 4. US Air Force 5. National Transportation Safety Board 6. Glen Meyerowitz (former SpaceX engineer) 7. Kathryn Lueders (NASA's Commercial Crew Program manager) [86995]

Software Taxonomy of Faults

Category Option Rationale
Recurring unknown The provided article does not mention any software failure incident happening again at the same organization (a) or at multiple organizations (b). Therefore, the information related to these options is 'unknown'.
Phase (Design/Operation) unknown (a) The software failure incident related to the design phase: The incident involving the SpaceX Crew Dragon capsule explosion was not directly attributed to a software failure in the design phase. The failure was explained as a leak in the spacecraft's pressurization system that led to a chemical reaction destroying the spacecraft [86995]. (b) The software failure incident related to the operation phase: The incident involving the SpaceX Crew Dragon capsule explosion was not directly attributed to a software failure in the operation phase. The failure was explained as a leak in the spacecraft's pressurization system that led to a chemical reaction destroying the spacecraft [86995].
Boundary (Internal/External) within_system (a) within_system: The software failure incident involving the SpaceX Crew Dragon capsule explosion was attributed to a leak in the spacecraft's pressurization system that allowed a liquid oxidizer to make contact with a titanium valve, leading to an unexpected explosive reaction [86995]. This issue was identified as a problem entirely within the pressurization system and not tied to any flaws in the Crew Dragon's engines. SpaceX planned to address this by replacing the valves with burst disks to mitigate the risk [86995]. (b) outside_system: There is no specific mention in the articles about contributing factors originating from outside the system leading to the software failure incident.
Nature (Human/Non-human) human_actions (a) The software failure incident in the SpaceX Crew Dragon explosion was not directly attributed to non-human actions but rather to a leak in the spacecraft's pressurization system that allowed a liquid oxidizer to make contact with a titanium valve, leading to an unexpected explosive reaction [86995]. (b) The failure in the SpaceX Crew Dragon explosion was due to contributing factors introduced by human actions, specifically the design and implementation of the pressurization system that allowed the leak to occur, resulting in the destructive chemical reaction [86995].
Dimension (Hardware/Software) hardware (a) The software failure incident in the SpaceX Crew Dragon explosion was not directly related to software issues but rather to a hardware failure. The incident was attributed to a leak in the spacecraft's pressurization system that allowed a liquid oxidizer to make contact with a titanium valve, leading to an unexpected explosive reaction [86995]. The problem was within the hardware system, specifically the pressurization system, and not tied to any flaws in the Crew Dragon's engines. (b) There is no information in the provided article indicating that the software failure incident was due to contributing factors originating in software. The focus of the incident was on a hardware-related issue involving a leak in the pressurization system leading to the explosion of the SpaceX Crew Dragon capsule during a ground test [86995].
Objective (Malicious/Non-malicious) non-malicious (a) The software failure incident related to the SpaceX Crew Dragon capsule explosion was non-malicious. The incident was attributed to a leak in the spacecraft's pressurization system that allowed a liquid oxidizer to make contact with a titanium valve, leading to an unexpected explosive reaction [86995]. The company stated that the reaction between titanium and the oxidizer at high pressure was not expected, indicating that the failure was not due to malicious intent but rather a technical flaw in the system.
Intent (Poor/Accidental Decisions) accidental_decisions [86995] The software failure incident involving the SpaceX Crew Dragon capsule explosion was not directly related to software issues but rather to a leak in the spacecraft's pressurization system that led to a surprising chemical reaction. This incident can be categorized more as an accidental_decisions failure, as it was caused by a leak allowing a liquid oxidizer to make contact with a titanium valve, resulting in an unexpected explosive reaction. The incident was not due to poor decisions but rather an unintended consequence of the pressurization system design.
Capability (Incompetence/Accidental) accidental (a) The software failure incident in the SpaceX Crew Dragon explosion was not directly related to development incompetence. The incident was attributed to a leak in the spacecraft's pressurization system that allowed a liquid oxidizer to make contact with a titanium valve, leading to an unexpected explosive reaction [86995]. (b) The software failure incident in the SpaceX Crew Dragon explosion was accidental. It was caused by a leak in the spacecraft's pressurization system that allowed a liquid oxidizer to make contact with a titanium valve, resulting in an unexpected explosive reaction between the two substances [86995].
Duration unknown The software failure incident described in the article is not related to a permanent or temporary software failure. Instead, it is related to a physical failure involving a leak in the spacecraft's pressurization system that led to a surprising chemical reaction, ultimately resulting in the explosion of the SpaceX Crew Dragon capsule during a ground test at Cape Canaveral [86995].
Behaviour crash, other (a) crash: The software failure incident in the SpaceX Crew Dragon capsule explosion can be categorized as a crash. The incident led to the destruction of the spacecraft during a ground test at Cape Canaveral in Florida, where the system lost its state and failed to perform its intended functions, resulting in the unexpected explosion [Article 86995]. (b) omission: There is no specific mention of the software failure incident being related to omission in the articles. (c) timing: The software failure incident is not related to timing issues where the system performs its intended functions but too late or too early. (d) value: The software failure incident is not related to the system performing its intended functions incorrectly. (e) byzantine: The software failure incident is not related to the system behaving erroneously with inconsistent responses and interactions. (f) other: The behavior of the software failure incident can be categorized as a crash due to the unexpected explosion during the ground test, leading to the destruction of the spacecraft [Article 86995].

IoT System Layer

Layer Option Rationale
Perception None None
Communication None None
Application None None

Other Details

Category Option Rationale
Consequence delay, non-human, theoretical_consequence (a) death: People lost their lives due to the software failure - There is no mention of any deaths resulting from the software failure incident involving the SpaceX Crew Dragon capsule explosion at Cape Canaveral [86995]. (b) harm: People were physically harmed due to the software failure - The article does not mention any physical harm to individuals as a result of the software failure incident involving the SpaceX Crew Dragon capsule explosion at Cape Canaveral [86995]. (c) basic: People's access to food or shelter was impacted because of the software failure - The incident did not impact people's access to food or shelter as it was related to a spacecraft explosion during a ground test [86995]. (d) property: People's material goods, money, or data was impacted due to the software failure - The software failure incident involving the SpaceX Crew Dragon capsule explosion did result in the destruction of the spacecraft itself, but there is no mention of any impact on people's material goods, money, or data [86995]. (e) delay: People had to postpone an activity due to the software failure - The incident did cause delays in the Crew Dragon program as further testing and modifications were required, potentially impacting the timeline for crewed flights to space [86995]. (f) non-human: Non-human entities were impacted due to the software failure - The software failure incident impacted the SpaceX Crew Dragon spacecraft, resulting in its destruction during the ground test at Cape Canaveral [86995]. (g) no_consequence: There were no real observed consequences of the software failure - The software failure incident involving the SpaceX Crew Dragon capsule explosion had significant consequences, including the destruction of the spacecraft and the need for modifications to prevent future incidents [86995]. (h) theoretical_consequence: There were potential consequences discussed of the software failure that did not occur - The article mentions potential consequences such as the impact on the reusability of the spacecraft due to changes in the valves, as noted by a former SpaceX engineer on Twitter [86995]. (i) other: Was there consequence(s) of the software failure not described in the (a to h) options? What is the other consequence(s)? - The article does not mention any other specific consequences of the software failure incident beyond those already discussed [86995].
Domain knowledge (a) The failed system in this incident was related to the space exploration industry. The SpaceX Crew Dragon capsule, which exploded during a ground test, is part of NASA's Commercial Crew program aimed at delivering astronauts to space [86995].

Sources

Back to List