Author Topic: AS-206 Near-catastrophic Failure  (Read 4116 times)

Offline Proponent

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AS-206 Near-catastrophic Failure
« on: 07/17/2010 04:46 AM »
Saturn I/IB never failed outright, but the first Saturn IB launched from LC-39B came within a fraction of a second of shutting down at T-0, due to a previously unknown timing issue that manifested itself on the new platform.  The rocket very nearly faltered, which would have caused it to blow up on its launch platform on live TV.  Crew survival odds were  iffy for that scenario.

Very interesting.  Would you have any documents on this?  I snooped around on NTRS but couldn't find anything relevant (although I did turn up some interesting docs about a proposed Apollo-era AS-206 mission which would have placed an S-IVB with no payload in LEO to demonstrate S-IVB restart before test S-IVB restart in the event of problems on AS-501).
« Last Edit: 07/17/2010 06:36 AM by Proponent »

Offline edkyle99

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Re: AS-206 Near-catastrophic Failure
« Reply #1 on: 07/17/2010 06:06 AM »
Saturn I/IB never failed outright, but the first Saturn IB launched from LC-39B came within a fraction of a second of shutting down at T-0, due to a previously unknown timing issue that manifested itself on the new platform.  The rocket very nearly faltered, which would have caused it to blow up on its launch platform on live TV.  Crew survival odds were  iffy for that scenario.

Very interesting.  Would you have any documents on this?  I snooped around on NTRS but couldn't find anything relevant (although I did turn up some interesting docs about a proposed Apollo-era AS-206 mission which would have placed an S-IVB with no payload in LEO to demonstrate S-IVB restart before AS-501).

It is in the SA-206 Flight Evaluation Report (Skylab II), which should be available here:   http://klabs.org/history/history_docs/jsc/jsc_mirror.htm.  The following description in the report provides some insight.

"3.5.2 MSFC Furnished Ground Support Eouipment

Postlaunch revieulr of the DEE-6 print out revealed that at 102 milliseconds
after cornnit, the Saturn IB ESE issued a momentary cutoff signal.
This signal was substantiated by the recording of a thrust failure
indication and cutoff start indication during one scan of the DEE-6.
The cutoff signal was not of sufficient duration to energize the cutoff
relay (K-72). See Figure 3-l."

Now the chilling part:

"If the erroneous cutoff signal had been sustained long enough to
energize the cutoff relay, an improper automatic cutoff sequence would
have been initiated. Vehicle power would have been transferred from
internal to external without engine cutoff resulting in launch without
vehicle electrical power and mission or vehicle loss (see Figure 3-l)."

 - Ed Kyle
« Last Edit: 07/17/2010 06:08 AM by edkyle99 »

Offline Proponent

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Re: AS-206 Near-catastrophic Failure
« Reply #2 on: 07/17/2010 08:59 AM »
Wow, that is scary.  You can imagine the headline: "Zombie Rocket Kills Astronauts, Destroys Launch Pad."

I vaguely recall reading about a proposal to launch a unmanned IB from the milk stool as a test.  Called Project Cannonball, IIRC, it would have orbited an inert sphere of metal (depleted uranium?).  Equipped with retro-reflectors, the sphere would have been the monster version of the LAGEOS geodetic satellites that later flew.  I had previously thought that it was silly to bother testing the launch pad, but now I see it would probably have been a good idea.

Offline Proponent

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Re: AS-206 Near-catastrophic Failure
« Reply #3 on: 11/16/2011 04:23 AM »
I vaguely recall reading about a proposal to launch a unmanned IB from the milk stool as a test.

From NTRS comes a 1971 paper on the Smithsonian Earth Physics Satellite, an 8000-lb depleted-uranium sphere with laser retro-reflectors to have been launched on a Saturn IB (specifically S-IB 212 + S-IVB 513 + IU-212).

The paper mentions that other proposals for payloads to be lofted by a Saturn IB to verify launch from LC-39 were under consideration.  Does anyone have any idea what these other payloads might have been?
« Last Edit: 11/16/2011 04:25 AM by Proponent »

Offline simonbp

Re: AS-206 Near-catastrophic Failure
« Reply #4 on: 11/16/2011 05:07 AM »
Wow, you could never pull that off today. I mean, it's certain high TRL (!), and there was good science it could have done (and which GRACE ended up doing decades later), but damn, that thing would be a nightmare on reentry!

Offline Graham2001

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Re: AS-206 Near-catastrophic Failure
« Reply #5 on: 11/17/2011 11:18 PM »
Very interesting.  Would you have any documents on this?  I snooped around on NTRS but couldn't find anything relevant (although I did turn up some interesting docs about a proposed Apollo-era AS-206 mission which would have placed an S-IVB with no payload in LEO to demonstrate S-IVB restart before test S-IVB restart in the event of problems on AS-501).

Here's a link to the document on the only document I knew about the AS-206 SIVb restart test on the NTRS, if there are others I'd be interested in looking at them.

AS-206 S-4B restart alternate mission L/V operational flight trajectory, part 3

Offline manboy

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Re: AS-206 Near-catastrophic Failure
« Reply #6 on: 11/18/2011 01:29 AM »
Wow, that is scary.  You can imagine the headline: "Zombie Rocket Kills Astronauts, Destroys Launch Pad."
Not to mention Skylab would most likely be lost by the time they could launch another crew.
"Cheese has been sent into space before. But the same cheese has never been sent into space twice." - StephenB

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