# Shuttle Columbia and Foam Strike

**URL:** <https://boards.straightdope.com/t/shuttle-columbia-and-foam-strike/197929>\
**Category:** Factual Questions\
**Created:** [August 27, 2003, 7:00am UTC](https://boards.straightdope.com/t/shuttle-columbia-and-foam-strike/197929 "2003-08-27T07:00:38Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![bcullman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bcullman/32/8207_2.png) [@bcullman](https://boards.straightdope.com/u/bcullman)\
**Post date:** [August 27, 2003, 7:00am UTC](https://boards.straightdope.com/t/shuttle-columbia-and-foam-strike/197929/1 "2003-08-27T07:00:38Z")

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for the report, engineers shot pieces of foam out of a cannon at 500mph and proved that foan traveling that fast could indeed create damage that would cuase a catastophic failure of the shuttle.

But would the foam really strike at that speed? the moment the foam seperated from the shuttle it began decelerating, sure. But being only recently attached to the shuttle, it still had forward momentum - wouldn’t that make the resulting impact happen at a much lower speed?

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**Author:** ![scr4](https://avatars.discourse-cdn.com/v4/letter/s/59ef9b/32.png) [@scr4](https://boards.straightdope.com/u/scr4)\
**Post date:** [August 27, 2003, 7:17am UTC](https://boards.straightdope.com/t/shuttle-columbia-and-foam-strike/197929/2 "2003-08-27T07:17:47Z")

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I believe they determined the impact speed from the film footage, so it should be pretty accurate. At such high speeds, anything not bolted down to the shuttle will decelerate very quickly due to air resistance, especially something light and irregularly shaped like a chunk of foam.

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**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\
**Post date:** [August 27, 2003, 7:18am UTC](https://boards.straightdope.com/t/shuttle-columbia-and-foam-strike/197929/3 "2003-08-27T07:18:43Z")

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But the shuttle is also accelerating _very_ fast. How long did it take between the time the foam broke off and when it struck the wing?

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**Author:** ![rsa](https://avatars.discourse-cdn.com/v4/letter/r/839c29/32.png) [@rsa](https://boards.straightdope.com/u/rsa)\
**Post date:** [August 27, 2003, 1:09pm UTC](https://boards.straightdope.com/t/shuttle-columbia-and-foam-strike/197929/4 "2003-08-27T13:09:19Z")

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The answer can be found in a sidebar on page 60 of the official [Columbia Accident Investigation Board report](http://i.a.cnn.net/cnn/SPECIALS/2003/shuttle/CAIB.report.pdf). (Warning: 10 MB PDF. MSNC has the report broken into sections; this quote is from Chapter 3.)

> [@](#):
>
> “How could a lightweight piece of foam travel so fast and hit  
> the wing at 545 miles per hour?”
> 
> Just prior to separating from the External Tank, the foam was  
> traveling with the Shuttle stack at about 1,568 mph (2,300  
> feet per second). Visual evidence shows that the foam debris  
> impacted the wing approximately 0.161 seconds after  
> separating from the External Tank. In that time, the velocity  
> of the foam debris slowed from 1,568 mph to about 1,022  
> mph (1,500 feet per second). Therefore, the Orbiter hit the  
> foam with a relative velocity of about 545 mph (800 feet per  
> second). In essence, the foam debris slowed down and the  
> Orbiter did not, so the Orbiter ran into the foam. The foam  
> slowed down rapidly because such low-density objects have  
> low ballistic coefficients, which means their speed rapidly  
> decreases when they lose their means of propulsion.

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**Author:** ![rsa](https://avatars.discourse-cdn.com/v4/letter/r/839c29/32.png) [@rsa](https://boards.straightdope.com/u/rsa)\
**Post date:** [August 27, 2003, 1:16pm UTC](https://boards.straightdope.com/t/shuttle-columbia-and-foam-strike/197929/5 "2003-08-27T13:16:10Z")

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Here is the [MSNBC link](http://www.msnbc.com/modules/interactive.asp?id=/d/ip/ColumbiaReport_Links/data.js&navid=SPACENEWS&0cv=TA01) which has the report available by chapter if you have a slow internet connection.