# The Great Kersten Blunder: was it real? **URL:** \ **Category:** Factual Questions\ **Created:** [April 27, 2016, 7:31pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275 "2016-04-27T19:31:38Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [April 27, 2016, 7:31pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/1 "2016-04-27T19:31:38Z")
A Google search for “the great Kersten Blunder” turns up many results, [such as this one.](http://measurementmishaps.blogspot.com/2014/08/the-great-kersten-blunder.html) The claim is that a programmer named Kersten screwed up a measurement conversion factor, causing the $2B “Vigor space probe” to miss Venus and become lost in space. The problem is that I can’t find any mention of a “Vigor space probe” that identifies who launched it or what its mission was. So what’s the deal? Was there actually a “space probe” named Vigor, targeted at the planet Venus, that was lost due to a faulty measurement conversion factor in the software? ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [April 27, 2016, 7:37pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/2 "2016-04-27T19:37:55Z")
What exactly is the Vigor space probe? I can’t find it. ---
**Author:** ![crowmanyclouds](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crowmanyclouds/32/19884_2.png) [@crowmanyclouds](https://boards.straightdope.com/u/crowmanyclouds)\ **Post date:** [April 27, 2016, 7:42pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/3 "2016-04-27T19:42:25Z")
Try the [Mars Climate Orbiter](https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure). CMC fnord! ---
**Author:** ![dasmoocher](https://avatars.discourse-cdn.com/v4/letter/d/dbc845/32.png) [@dasmoocher](https://boards.straightdope.com/u/dasmoocher)\ **Post date:** [April 27, 2016, 7:45pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/4 "2016-04-27T19:45:36Z")
Hopefully, it won’t come back as [V’gor](http://memory-alpha.wikia.com/wiki/V'ger). ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [April 27, 2016, 7:51pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/5 "2016-04-27T19:51:20Z")
> [@crowmanyclouds](#): > > Try the [Mars Climate Orbiter](https://en.wikipedia.org/wiki/Mars_Climate_Orbiter#Cause_of_failure). > > CMC fnord! That one gets mentioned on metrology websites in the same list as the great Kersten Blunder, IOW they seem to be regarded as two independent things (although the MCO, and the nature of its demise, is very well documented). ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [April 27, 2016, 7:59pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/6 "2016-04-27T19:59:11Z")
Well then did it, or rather does it, actually exist? ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [April 27, 2016, 8:10pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/7 "2016-04-27T20:10:02Z")
> [@Grey](#): > > Well then did it, or rather does it, actually exist? :dubious: You’re asking one of the questions I implicitly asked in my OP. Given the lack of specifics on the internet about who might have launched it and why, until someone can present evidence to the contrary, I’m inclined to think it never existed. ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [April 27, 2016, 8:10pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/8 "2016-04-27T20:10:49Z")
What was his first name? Kersten and Vigor sounds like something made up on the web that people find and copy without fact-checking. ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [April 27, 2016, 8:29pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/9 "2016-04-27T20:29:28Z")
It sounds made up to me. Official lists of space probes to Venus (or anywhere in the solar system) do not include any _Vigor_ probe. I sent an email to the Bad Astronomer to see if he’s familiar with the story and can shed any light. I’ll post back if I get a response. ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [April 27, 2016, 8:29pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/10 "2016-04-27T20:29:39Z")
> [@Saint\_Cad](#): > > What was his first name? > Kersten and Vigor sounds like something made up on the web that people find and copy without fact-checking. I agree - which is why I’m asking around for facts. 😃 ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [April 27, 2016, 8:40pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/11 "2016-04-27T20:40:30Z")
And a response already from the Bad Astronomer! [QUOTE=Phil Plait] Hi- To my knowledge there never was a Vigor probe. I wonder if this story was made up, or was part of a short story that got out into the wild. I see it used as if it really happened. Interesting. I might write about this, if I find a hook for it (like the origin of it). Very weird! [/QUOTE] ---
**Author:** ![usedtobe](https://avatars.discourse-cdn.com/v4/letter/u/ec9cab/32.png) [@usedtobe](https://boards.straightdope.com/u/usedtobe)\ **Post date:** [April 27, 2016, 10:00pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/12 "2016-04-27T22:00:20Z")
How subtle: Using “Vigor” to probe “Venus”. My inner 13 yr old is snickering… ---
**Author:** ![TroutMan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/troutman/32/6721_2.png) [@TroutMan](https://boards.straightdope.com/u/TroutMan)\ **Post date:** [April 28, 2016, 3:09pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/13 "2016-04-28T15:09:44Z")
I made one last stab and sent an inquiry to the [National Physical Laboratory](http://www.npl.co.uk/), who published an educational guide to measurement in mechanical engineering that includes the Kersten Blunder as an anecdote. I asked if they knew the source of the story, and received a very nice response that “sadly, it may indeed be recycling an urban myth.” And as evidence, he linked to this thread. 🙂 ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [April 28, 2016, 3:24pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/14 "2016-04-28T15:24:21Z")
> [@TroutMan](#): > > I made one last stab and sent an inquiry to the [National Physical Laboratory](http://www.npl.co.uk/), who published an educational guide to measurement in mechanical engineering that includes the Kersten Blunder as an anecdote. I asked if they knew the source of the story, and received a very nice response that “sadly, it may indeed be recycling an urban myth.” > > And as evidence, he linked to this thread. 🙂 This is all becoming weirdly incestuous. [The guide you mentioned](http://www.npl.co.uk/publications/guides/beginners-guide-to-measurement-in-mechanical-engineering) is the very one in which I first read about the Great Kersten Blunder (and why I inquired here! 😃 ---
**Author:** ![Saint\_Cad](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/saint_cad/32/18907_2.png) [@Saint\_Cad](https://boards.straightdope.com/u/Saint_Cad)\ **Post date:** [April 28, 2016, 3:26pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/15 "2016-04-28T15:26:33Z")
This thread is rapidly getting very meta. ---
**Author:** ![Andy\_L](https://avatars.discourse-cdn.com/v4/letter/a/c67d28/32.png) [@Andy\_L](https://boards.straightdope.com/u/Andy_L)\ **Post date:** [April 28, 2016, 3:31pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/16 "2016-04-28T15:31:06Z")
There was a Venus probe (Mariner 1) which failed due to a typo in the code specification [Mariner 1 - Wikipedia](https://en.wikipedia.org/wiki/Mariner_1#.22The_most_expensive_hyphen_in_history.22) - I wonder if that story got merged with the Mars Climate story to create this “Kersten” blunder story. ---
**Author:** ![aldiboronti](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@aldiboronti](https://boards.straightdope.com/u/aldiboronti)\ **Post date:** [April 28, 2016, 3:40pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/17 "2016-04-28T15:40:18Z")
> [@Andy\_L](#): > > There was a Venus probe (Mariner 1) which failed due to a typo in the code specification [Mariner 1 - Wikipedia](https://en.wikipedia.org/wiki/Mariner_1#.22The_most_expensive_hyphen_in_history.22) - I wonder if that story got merged with the Mars Climate story to create this “Kersten” blunder story. That sounds quite possible. The Vigor name may be an echo of the two Venus landers, Vega 1 and Vega 2. ---
**Author:** ![AskNott](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/asknott/32/5790_2.png) [@AskNott](https://boards.straightdope.com/u/AskNott)\ **Post date:** [April 28, 2016, 6:09pm UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/18 "2016-04-28T18:09:42Z")
Perhaps there’s a rocket scientist named Kersten somewhere, having to periodically deny he was to blame for that legendary blunder that probably never happened. ---
**Author:** ![glowacks](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/glowacks/32/5548_2.png) [@glowacks](https://boards.straightdope.com/u/glowacks)\ **Post date:** [April 29, 2016, 3:07am UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/19 "2016-04-29T03:07:57Z")
Depending on the two interlocutors’ accents, someone might hear “Vigor” from someone saying “Vega”. ---
**Author:** ![Senegoid](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/senegoid/32/6606_2.png) [@Senegoid](https://boards.straightdope.com/u/Senegoid)\ **Post date:** [April 29, 2016, 3:19am UTC](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275/20 "2016-04-29T03:19:45Z")
> [@Andy\_L](#): > > There was a Venus probe (Mariner 1) which failed due to a typo in the code specification [Mariner 1 - Wikipedia](https://en.wikipedia.org/wiki/Mariner_1#.22The_most_expensive_hyphen_in_history.22) - I wonder if that story got merged with the Mars Climate story to create this “Kersten” blunder story. As the above-linked Wiki pages documents, there is a lot of speculation over what happened. The thing about the hyphen is just one story that got around. At the time, or for some time thereafter, the standard story going around was that it was a one-character punctuation error in a FORTRAN program: DO 5 K = 1. 3 that should have been DO 5 K = 1, 3 In FORTRAN, both of the above are valid and mean very different things. That was the widely-held story. The Wiki page now debunks that, suggesting a lot of different hypotheses. [Next page](https://boards.straightdope.com/t/the-great-kersten-blunder-was-it-real/753275.md?page=2)