Re: PAL ramp photos


Craig Fink wrote:
> Upper PAL ramp that didn't fall off:
>
> http://t2www.nasa.r3h.net/images/content/106845main_1093-LO2_PAL_Ramp_0019_2560x1920.jpg
>
> Lower PAL ramp with part of it removed to access the intertank (notice the
> nice clean cut in the lower portion to do the work):
>
> http://www.nasa.gov/images/content/104631main_99600main_PAL_Ramp_8-12-04_3000x2000.jpg
>
> Good view of the Upper and Lower PAL ramp with the close out foam (repair)
> in place. Also, notice how much bigger and further forward the upper PAL
> ramp appears:
>
> http://t2www.nasa.r3h.net/images/content/110206main_1119-ET-121__5808_3072x2048.jpg
>
> ET in orbit picture with part of the PAL ramp missing. Notice you can see
> the Intertank closeout cut and repair to the PAL ramp is forward of the
> PAL ramp debris location. Also, look at the sharp forward edge of the
> debris location, looks similar to the intertank access cut to the PAL ramp:
>
> http://www.nasa.gov/images/content/123625main_s114e5070_high.jpg
>
> Did the PAL ramp debris originate at a repair site?

Looks like a different site to me, but it looks
like there might be another discoloration near
the failure site in the third photo. The whole
ramp looked like it had been monkeyed with a lot.

One interesting thing I notice in the last photo
is that the point of failure is almost dead center
in the PAL ramp, about halfway between top and
bottom. Wouldn't this be a spot where, if the
thing flexed when the tank vibrated at SRB sep,
the deflection on the PAL ramp foam would be the
greatest?

I'm wondering if the foam issues are the result of
an accumulation of modifications meant to up the
payload capabilities to ISS. One was the lighter
external tank, which surely must have changed the
way the tank walls move/vibrate/shudder during flight.
Another was hotter SSMEs, which, AIRC, were upped
in thrust and changed in other ways during the late
1990s.

- Ed Kyle

.

Relevant Pages

  • PAL ramp photos
    ... Lower PAL ramp with part of it removed to access the intertank (notice the ... Did the PAL ramp debris originate at a repair site? ...
    (sci.space.shuttle)
  • Re: PAL ramp photos
    ... >> Lower PAL ramp with part of it removed to access the intertank (notice the ... >> Good view of the Upper and Lower PAL ramp with the close out foam (repair) ... the intertank access cut/repair, ...
    (sci.space.shuttle)
  • Re: Griffins Plan to Scuttle Shuttle?
    ... insulation on that one portion, they're now willing to sacrifice a ... I don't think it had to do with boil off. ... As a result, the tank was equipped with two PAL ramps, one ... look and they've done so and concluded that the PAL ramp actually ...
    (sci.space.policy)