Challenger SRBs

[georgeniebling]

OK: stupid questions I prolyl know the answers to if I think about them but I'll defer to the experts.<br /><br />Most of the video footage of the Challenger accident stays with the larger cloud .... what happened to the SRBs following the explosion and their seperation in that explosion?<br /><br />Did they burn out?<br />Were that terminated by range staff?<br />Were they recovered?<br /><br />Was the "good" SRB able to be salvaged?<br /><br />

 

[zavvy]

This link might help you..

 

[georgeniebling]

I appreciate the link ... it does mention that the onboard termination explosives were used at 110 seconds ... that raises the curiousity as to why to took that long for Range Safty to destroy them ...

 

[zavvy]

You might find some answers in the following link..<br /><br />Report of the Presidential Commission on the Space Shuttle Challenger Accident

 

[viper101]

Funny that you are asking about Challenger. For some reason, I woke up in the middle of the night last night, and all I could think about was the 51L crew and how there are indications that they survived the explosion. The though of two + minutes of freefall after something like that - it just made me sick to imagine their circumstance. The confusion. The fear. I know it sounds starnge to metion this nearly 20 years later, but it had never hit me the way it did last night. I spent part of the morning googling reports on the crew cabin recovery etc etc...<br /><br />Still very sad after all these years.

 

[shuttle_rtf]

>but it had never hit me the way it did last night. I spent part of the morning googling reports on the crew cabin recovery etc etc... <<br /><br />A lot of that is unavailable for obvious reasons...Columbia's crew only has a line or two stating the obvious <img src="/images/icons/frown.gif" />

 

[najab]

If it helps ease your mind any, the emergency air packs didn't supply pressurized oxygen, so they would likely have been unconscious from anoxia fairly quickly.

 

[drwayne]

The only if in that would be "if the crew cabin lost pressure", then the airpacks would not help. It is did not, then they would have been concious all the way down. The fact that they activated them would indicate to me that there was a reason, i.e. the cabin was losing pressure...<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[silylene old]

Way back...about 2 years prior Challenger, inspired after reading a supplier's junk mail advertisement on o-ring materials, I remember discussing with friends that the o-ring materials choice was not well thought through (Viton o-rings). At the time, I wondered why the engineers had not chosen Kalrez (very expensive!) or a silicone o-ring material because of their very superior thermal properties. And, since there have been several o-ring burnthroughs on different missons (old-tang design), I thought then (and still think!!) that the o-ring thermal decomposition temperature should be given very high consideration.<br /><br />data from an o-ring table I have:<br />o-ring material/ / brittle point / / decomposition temperature///% elongation 'til breakage//%compression set at 200C<br />EPDM // -40C//121C//200%//NA -decomposes<br />VITON //-13C//204C//125%//45%<br />Silicone //-90C//235C//?//?<br />Kalrez / / -45C / / 349C / /180%//30%<br /><br />chemical inertness:<br />EPDM - rather bad to greases<br />VITON - OK to some greases<br />Silicone - swells badly<br />Kalrez - absolutely inert in almost everything by HF<br /><br />Then I find this reference from 1992, http://techreports.larc.nasa.gov/ltrs/PDF/tp3226.pdf in which the NASA researcher recommends a new grade of Viton o-ring for the upgraded SRB, good to -26C, which is apparently what we use today. The basic reason driving this choice is that the o-ring must be compatible with a calcium containing grease (page 4) used to seat the o-ring and to help prevent corrosion. Kalrez o-rings were never considered by this researcher.<br /><br />My opinion as a chemist is that this report is of rather limited research quality. What the researchers should have done is first to test the thermal elastic properties of the full range of o-ring materials available, using a gease compatible for each, and then make the o-ring decision. The grease used to seat t <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>

 

[georgeniebling]

SG .... wow, I know we've discussed this here before over the years but I don't think I ever realized you thoughts ... that must have been horrible for them if you're right.<br /><br />Curiousity ... do you know how soon after (approx.) the explosion the remains of the crew cabin made impact and how soon after that first contact by recovery forces with the crew cabin was made?<br /><br />I know there was no possible chance of a "good" recovery .... I say a prayer for them everytime we get started on this subject ....<br /><br /><br />BTW, SG ... I noticed you did a copy/paste from this thread to the STS-121 prep thread ...

 

[shuttle_rtf]

I was doing a paper round as young teenager and got back to the newsagents and heard someone saying "The Space Shuttle's exploded".<br /><br />I ran home and asked my mum to put on the TV - which was showing the downrange field.<br /><br />Watched it all night and the next day went to get some books on Shuttles. <br /><br />So when I say I got into Shuttles in 1986 - that's what I mean.