[oasis-members] A question: How could this have been prevented?

[Robert Gounley]

In looking for specifics, I found the blog below. (more about that later)

The uppermost portion of unmanned launch vehicles, the part most 
vulnerable to hail damage, is its launch shroud.  (It protects the 
satellite through ascent until jettisoned upon leaving the atmosphere.)  
Being primarily a "wind break", the shroud's exterior is lightweight 
structural materials.  I believe the ones made today use kevlar, 
resistant to the pounding of even 4 cm diameter hail.  Earlier ones 
would have used the thin metal sheeting -- I don't know if any of them 
suffered hail damage (or if anyone then was predisposed to look).

The shuttle, with its cryogenic fuel tank uppermost, presents foam 
insulation to the hail.  It's pretty resilient foam capable of repelling 
a fusillade of typical Florida hailstones -- pea to marble size.  
Broadsides of ice missiles the size of billiard balls take armor, or at 
least some kind of deflector. 

Against bombardments like this, I'd propose tarp shaped like a circus 
tent around the top of the External Tank.  The biggest challenge would 
be to keep it in place during heavy winds -- a much more common 
occurrence.  A loose flap and guy wire whipping the tank would do much 
worse damage than the hail.

Other suggestions?
------------------------------------------------------------------------

(from 
http://wwwa.accuweather.com/news-blogs.asp?blog=community&partner=accuweather)

Large *Hail* Damages NASA Shuttle
Tuesday, February 27, 2007

*UPDATE:* I have watched the NASA 
<http://wwwa.accuweather.com/news-blogs.asp?blog=community&partner=accuweather#> 
TV report mentioned below. A summary based on what I heard:

/They didn't see any irony in that the main speaker was Wayne /Hale/. 
<http://www.nasa.gov/centers/kennedy/about/biographies/hale.html>/

/NASA had recently made external improvements and was proud to have "the 
cleanest tank ever flown" -- until the *hail* started. /

/The storm was "an unusual set of circumstances", extremely severe and 
localized over Launch Complex 39 where the shuttle was parked. It was 
described as an "explosion" of meteorological mayhem, with a lot of golf 
ball sized, 1.5" diameter of *hail*, accompanied by 62-mph wind gusts. 
*Hail* is not unusual in Florida, though this is early in the season. 
Usually the *hail* is quite small and rarely causes damage. /

/Damage was 360 degrees on the foam -- it was the worst damage they have 
ever seen from *hail* on the external tank foam. Hundreds of spots will 
have to be sanded or blended, or they will have to pour foam into the 
divots. The Shuttle will have to be moved back to the assembly building. 
Two dozen orbiter tiles suffered cosmetic surface damage and will 
require slurry or putty. The wings were damaged by wind blown, 
ricocheting *hail* which got under the orbiter weather-protection 
system. There was some damage on ice frost ramps. They will inspect 
other parts of the shuttle for damage through thermography. /



DRh9811850 at aol.com wrote:
> Once again, a shuttle launch has been delayed due to storm damage.
> Space Shuttle Damaged by Hail, Launch Delayed
>
> My question is this:  Since wild weather and the Florida coast are closely 
> connected, isn't there some way that they can do better to protect launch 
> vehicles? 
>
> It takes a heap of time (at least 8 hours) to roll the shuttle stack out to 
> the pad, and it occurs to me that *all* the vehicles launched from the Cape and 
> elsewhere need to consider this possibility. So why don't they? 
>
> Does anyone have any ideas how future launch vehicles could be more hardy 
> against this kind of damage? Portable kevlar slipcovers sound a tad expensive, 
> but so are launch vehicles... ;-)
>
> Diane Rhodes
>
>
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