Bad vibration issue on ISS when engines fired

[silylene old]

<p>Scary!&nbsp; "The thrashing of the long solar array wings reached a degree "five times greater than allowed," one source told msnbc.com in an e-mail. Another source said the swaying was the "biggest I've ever seen... Outside the certified limits of ISS structure&hellip;"</p><p>I wonder why there wasn't a 'kill switch'.&nbsp; Please click on the original link to watch a video.</p><p>&nbsp;</p><p>(Sorry, for some reason the Pluck editor won't allow me to delete the adevetising spam)</p><p>http://www.msnbc.msn.com/id/28998876/</p><h1>Shaking on space station rattles NASA</h1><h2>Vigorous vibrations caught on video during orbital reboost last month</h2><div class="p12"><div class="WCCol w300 fR clrR"><div style="padding-bottom:20px"><div class="box_3088867 sitewrapperbox cbx cbx-video" style="width:300px"><table border="0" cellspacing="0" cellpadding="0" width="300" class="boxH_3088867"><tbody><tr><td class="boxHI_3088867" width="1%"><img src="http://www.msnbc.msn.com/images/icons/video.gif" alt="" width="20" height="14" />

 

[JonClarke]

<p>Fairly typical anti-Russian scare story from James Oberg.&nbsp; Anonomyous sources&nbsp;and no confirming information.&nbsp;</p> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[silylene old]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>Fairly typical anti-Russian scare story from James Oberg.&nbsp; Anonomyous sources&nbsp;and no confirming information.&nbsp; <br />Posted by jonclarke</DIV><br /><br />Hi Jon, did you play the video?</p><p>&nbsp;</p><p>(yes I agree on your comments on Oberg's reputation))</p> <div class="Discussion_UserSignature"> <div class="Discussion_UserSignature" align="center"><em><font color="#0000ff">- - - - - - - - - - - - - - - - - - - - - -</font></em> </div><div class="Discussion_UserSignature" align="center"><font color="#0000ff"><em>I really, really, really miss the "first unread post" function.</em></font> </div> </div>

 

[JonClarke]

<p>It's certainly impressive! I can imagine such low frequency osccilations (~1 second)&nbsp;would certainly causing the wings to flap.&nbsp;But without comparison with normal burns, it's hard to judge the significance of this.&nbsp; </p><p>I can't imagine there not being an overide switch, but obviously the people at time time judged, rightly or wrongly, that the oscillation was acceptable.</p><p>Jon</p> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[rybanis]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>It's certainly impressive! I can imagine such low frequency osccilations (~1 second)&nbsp;would certainly causing the wings to flap.&nbsp;But without comparison with normal burns, it's hard to judge the significance of this.&nbsp; I can't imagine there not being an overide switch, but obviously the people at time time judged, rightly or wrongly, that the oscillation was acceptable.Jon <br /> Posted by jonclarke</DIV></p><p>See, thats what I thought: If they noticed this burn wasn't going well, then why did not abort before the oscillations got serious?&nbsp;</p><p>On a minimially related note, did anyone else see the HD video tour of the ISS that got posted to Youtube? Its amazing. The difference between the US/Euro/Japanese side and the Russian side are...stark. </p> <div class="Discussion_UserSignature"> </div>

 

[tanstaafl76]

<p>Well, that'll make ya crap your spacesuit!</p><p>&nbsp;</p> <div class="Discussion_UserSignature"> </div>

 

[JonClarke]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>See, thats what I thought: If they noticed this burn wasn't going well, then why did not abort before the oscillations got serious?&nbsp;</DIV></p><p>Thewre are lots of possibilities.&nbsp; Maybe it was not that serious.&nbsp; Maybe those controlling the burn did not think it was serious.&nbsp; At bthis stage we only have Oberg's claim that it was.</p><p>Jon</p> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[montmein69]

<p>&nbsp;</p><p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>If they noticed this burn wasn't going well, then why did not abort before the oscillations got serious? <br />&nbsp;</DIV></p><p>&nbsp;Did anyone find a document relating precisely what happened ?</p><p>&nbsp;</p><p>My question : </p><p>Did the vibrations begin during the first part of the burst, and then the computer stopped the engines (as the structure deformations were out of the range) ?</p><p>Or was it a "bad sequence" in the computer program, that caused a sudden stop of the engines ... and then that event created the vibrations ? </p> <div class="Discussion_UserSignature"> </div>

 

[trailrider]

<p>So, anything further on the potential damage assessment? Man, that's all we need!&nbsp; Leaks in the seals, damage to the solar panel hinges, and the Shuttle program winding down in a year or so... Talk about bad karma!</p><p>But let's not be worrying about Oberg's reputation or his blogs, etc.&nbsp; Let's get some facts, if possible!</p>

 

[JonClarke]

<p><BR/>Replying to:<BR/><DIV CLASS='Discussion_PostQuote'>So, anything further on the potential damage assessment? Man, that's all we need!&nbsp; Leaks in the seals, damage to the solar panel hinges, and the Shuttle program winding down in a year or so... Talk about bad karma!But let's not be worrying about Oberg's reputation or his blogs, etc.&nbsp; Let's get some facts, if possible! <br />Posted by trailrider</DIV></p><p>Why do people gto into such chicken little mode over the slightest problem with the ISS?&nbsp; </p><p>A factual report, unlike Oberg's attempt at FUD is on SDC http://www.space.com/missionlaunches/090205-space-station-crew.html</p><p>Bad karma?&nbsp; Bollocks!&nbsp; Any large experimental facility with have a few technical problems over a more trhan a decade of operation.</p><p>Jon</p> <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em>  Arthur Clarke</p> </div>

 

[franontanaya]

Ah, well... at least now we know that, if we ever want to push the ISS with an Ares I, it might not fall apart. <div class="Discussion_UserSignature"> </div>

 

[bushuser]

<font size="3">If&nbsp; I was on board, I'd prefer&nbsp;the gentle thrust of an ion engine.</font>