Elon Musk trying to make the best of a catastrophic failure
16 January 2024
The term rapid unplanned disassembly (also unscheduled) or RUD is a jocular euphemism used by engineers to refer to a catastrophic failure of a system. The term came to the attention of the general public in 2015 and then again in 2023 when it was used by Elon Musk and SpaceX engineers to describe such catastrophic failures of their rockets.
But the euphemism is several decades older. The first use that I have found is from 1991 and in the context of sailing. The Vancouver Sun of 16 October 1991 had this:
A major cause of the sudden catastrophic failure of a sail is flying it in conditions that exceed its designed wind speed limitations. Boats don’t go any faster with decks awash to the centreline and the mast horizontal, but sails have been known to go into “rapid unplanned disassembly” in those conditions.
Use in the world of aerospace dates to at least 2009, when it appears in a Purdue University master’s thesis:
However, several lessons were well learned over the course of 18 months. First, never assume a component is correctly assembled unless you want to have rapid unplanned disassembly of that particular component.
And we get the acronym RUD by 2012. From the September/October 2012 issue of Washington Monthly:
Any flaws in design or misunderstanding of the precise nature of the whorls and eddies result in what Scott calls a RUD—a “rapid unscheduled disassembly,” meaning the rocket blows up.
All these published uses were undoubtedly preceded by more informal uses by engineers joking about their failures.
Musk and SpaceX enter into the picture on 16 January 2015 when Musk tweeted the term after a crash of their Falcon 9 rocket. The Guardian newspaper of that date reports:
Private spaceflight company SpaceX has released new pictures of its Falcon 9 rocket attempting to land on a floating platform in the Atlantic Ocean before undergoing what its chief executive, Elon Musk, euphemistically referred to as “RUD” – that’s “Rapid Unscheduled Disassembly”.
In other words, it blew up.
Claims that the term originated in online discussions of the videogame Kerbal Space Program are incorrect. That game wasn’t released until 2015, well after the term was well established as an in-joke among engineers.
Sources:
Biewenga, Bill. “If You Look After Those Sails You’ll Save a Bundle of Money.” Vancouver Sun (British Columbia), 16 October 1991, D14/1. ProQuest Historical Newspapers.
Carey, Kevin. “The Siege of Academe.” Washington Monthly, 44/9-10, September/October 2012, 35–44 at 42/1. ProQuest Magazines.
Hern, Alex. “This Is What a ‘Rapid Unscheduled Disassembly’ Looks Like.” Guardian, 16 January 2015.
Sandroni, Alexander Michael. “Plume and Performance Measurements on a Plug Nozzle for Supersonic Business Jet Applications” (master’s thesis, Purdue U, May 2009, 124. ProQuest Dissertations.