posted 01-07-2008 10:45 AM               

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The year was 1966 and NASA was testing its first fully-assembled, 363-foot tall Saturn V moon rocket at its launch facilities in Florida. Despite the threat posed by a hurricane and a ruptured fuel line, the trials with the sky-scraping booster had gone well and it came time to separate the Saturn into its five stages in the voluminous Vertical Assembly Building that had been erected for that very purpose.

But NASA engineers had another idea: though the rocket had been analytically designed to be structurally stable, they saw the opportunity to gather some real world data about how the booster would react to vibrations imparted by wind and other outside forces.

So, they proposed to set the Saturn swaying. And what better way to do that than to exert force on the tower by having one group lie on their backs and push with their feet while another pulled a rope tied to the opposite side?

Really, what possibly could go wrong?

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posted 01-07-2008 06:56 PM               

Science and curiousity.

posted 01-09-2008 07:24 AM               

The sway brace was kept in place nearly full time until launch preps (and other times it interfered with checkout). I have a lot of footage of it being raised and lowered.

For confirmation, I wonder if a technical report might exist somewhere on the LUT detailing the need for the addition of the sway brace. My bet is there is some sort of reference to this event contained in documentation on the need for a sway brace. There is a report titled:

"Effectiveness of external dampers for attenuating launch vehicle oscillations."

on the NASA technical reports server, dated 1966, but it is not in pdf form.

Update: I found this report at AIAA, and while it makes no mention of the specific test, it is obviously created (in December 1966) to specifically look at Saturn V oscillations (due to ground wind) and concludes that a damper connected to the LUT may be a simple way to diminish the oscillations.

posted 01-09-2008 04:09 PM               

When you approached me about this when it was *found* on the net - I showed it to our retirees here in Downey that worked on Apollo - and they were in shock, as they thought it had to be an unauthorized event, as they had never heard of - or thought of doing such a thing to a full sized Saturn-5!!

Lets hope the next generation of engineers keeps this in mind for Orion/Ares!

posted 01-10-2008 06:15 AM               

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Originally posted by spacecraft films:
Update: I found this report at AIAA, and while it makes no mention of the specific test

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It was my and Alan Lawrie's hope that by publishing the article on cS and in Spaceflight magazine that those were were present and/or aware of the test for all these years might step forward with more information (as James Moos did, and whose comments were added to the article). If enough new information can be found or sourced, then a follow-up article may be merited.

posted 01-10-2008 08:19 AM            

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Originally posted by Robert Pearlman:
I wonder if the tower presently restored on the Saturn V 500-F/D in Huntsville is the one and the same that broke loose from its mounting ring as a result of this twang test.

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A large dent in one side? (sarcasm)

According to AFGAS, MSFC/USSRC have 1 real CM, 2 BP's and 3 LES to go along with them. CM-010 was on SA-500-D when she was outside, but apparently BP-23 was brought over from MSFC to possibly be included.

If we can find some info about this historically intriguing LES, I'll be happy to scour the item on SA-500-D when I visit USSRC in early Feb.

posted 01-11-2008 10:03 AM            

I'm hosting reduced versions of the pictures, click on them to see the originals.

Here's a picture of SA-500-F on the pad in 1966:

(NASA via ApolloArchive.com)

Look at the vertical and horizontal 'ridges' on the conical base just above the LES motor's nozzles. That was a hallmark of any production LES. Even though this was a weight dummy, the casing appears to be the same design as the production models. The LES that was on SA-500-D outside the USSRC was smooth:

(AFGAS)

BP-23, which was recently moved from MSFC for possible inclusion on SA-500-D, does have a real LES. Of course, this was no sand-filled dummy since it was used for abort tests at White Sands, NM in Dec 1964 and June 1965. No idea when it was moved to MSFC, and if it was part of the dynamic tests in 1966-67. Here's a picture courtesy of AFGAS:

Then there's BP-27 atop the Saturn I. Unless someone can point me to the proper NASA documents, I think it's a safe assumption that BP-27 and its LES have been with MSFC. Since the only indication I could find of its use is "Dynamic tests", it's possible that it took a ride on the SA-500-D stack. Who knows? (non-rhetorical)

So, I think it's safe to assume that Marshall didn't test SA-500-D with the infamous LES. According to AFGAS, the Facilities Verification Vehicle that sat atop SA-500-F is on the SA-209 Saturn IB display at KSC.

But taking a look at the LES attached to this vehicle...

(AFGAS)

Hmm. Were the vertical details straps running from the end of the LES tower to attachment points on the conical structure? Furthermore, why does this LES have a radically different tower from SA-500-F or any other LES I could find?

posted 02-05-2008 10:57 PM            

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Originally posted by Mr Meek:
One interesting note on AFGAS is that BP-27, which currently resides on top of the Saturn I at USSRC, is listed as being used for "dynamic tests".

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posted 02-06-2008 08:27 AM            

So, CM-010 = BP-27. According to this document, it's with SLA #1, which would've put it on the Saturn V outside. The Saturn I there obviously doesn't have an SLA. Of course, BP-27 could've been put on the Saturn I at some point.

BP-27, according to this document, has LES #16.

Interestingly, this document lists BP-23's utilization as "Display only."

And further down, there's mockup M-23, "CM, SM, and LES for Umbilical Tests (LES 015 at MSFC)." If the CSM/LES on SA-500-D was a mockup, it sounds like it was this one.

Surely someone at USSRC or MSFC would know what is what.