Strange events during STS-116

[docm]

Article....<br /><br /><blockquote><font class="small">In reply to:</font><hr /><p><b>NASA working another strange event seen on STS-116's boosters</b><br /><br /> By Chris Bergin, 2/22/2007 1:39:54 PM<br />Following the confirmation that a small piece of SRB (Solid Rocket Booster) insulation managed to apparently defy the laws of physics by travelling up the stack and strike the belly of Discovery, another strange event - which is still under investigation - has been noted by NASA managers in post STS-116 evaluations.<br /><br />Super high resolution video of STS-116's "Thermal Curtain Stabilization" shows what appears to be a large amount of flapping at the aft end of the left SRB, which continues to cause confusion as to exactly what was being observed. <br /> /><br /> /><p><hr /></p></p></blockquote> <br /><br />Sure hope the bottom end of Ares I doesn't find a way to flap around <img src="/images/icons/tongue.gif" /> <div class="Discussion_UserSignature"> </div>

 

[MeteorWayne]

I guess it is that you see a lot of funny stuff going on when you analyze everything in HD frame by frame.<br /><br />For the last 35 years of spaceflight, nothing like these two intersting items would ever have been noticed.<br /><br />Such efforts only increase safety moving forward.<br /><br /> <div class="Discussion_UserSignature"> <p><font color="#000080"><em><font color="#000000">But the Krell forgot one thing John. Monsters. Monsters from the Id.</font></em> </font></p><p><font color="#000080">I really, really, really, really miss the "first unread post" function</font><font color="#000080"> </font></p> </div>

 

[SpaceKiwi]

I'm just the social sciences guy, but I'm a little surprised that this is as surprising to the technical folks. This (shuttle launch) must have been modelled in wind tunnels countless times, but there's nothing like a dynamic real-time environment to throw up all kinds of funky air-flows I'd wager.<br /><br />It would be nice were it possible to throw a gigantic smoke machine at a few launches, and film the Stack's movement spaceward. It'd make those aircraft and sailboat flows seem positively old hat. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[propforce]

<font color="yellow"><i>I'm a little surprised that this is as surprising to the technical folks. This (shuttle launch) must have been modelled in wind tunnels countless times, but there's nothing like a dynamic real-time environment to throw up all kinds of funky air-flows I'd wager.</i></font><br /><br />First, I agree with the Shuttle_Guy that these "events" are not really a suprise to the technical folks. Observe in your own car when you drive at high speed, the back of car forms a "base" region which separates the air flow over the top and creates a air recirculating zone. The Shuttle further encourages this with both SRBs and 2 SSMEs going full blast, adding more "back pressure" to the base. So if a piece of flap falls off the SRB, it is conceivably that it will travel "forward" rather than "aft" first before being tumbled out to the airstream.<br /><br />Second, while wind tunnel testing provides valuable aerodynamic data, one can not test all possible scenarios for what will happen during a flight. Wind tunnel operation is expensive and the "Shuttle" is a sub-scale model (I think it's a 1/7th scale?). So there's really not practical to simulate a piece of flap off the SRB or the icing striking the TPS, etc.<br /><br /> <div class="Discussion_UserSignature"> </div>

 

[cyclonebuster]

My empty beer cans travel in all different directions in the bed of my truck, also! LOL!!!

 

[SpaceKiwi]

<blockquote><font class="small">In reply to:</font><hr /><p>These incidents actually were not a surprize....<p><hr /></p></p></blockquote><br />My apologies, I was just keying off Chris Bergin's article and his expression of supposed "confusion" on the part of the evaluation folks. I'll remind myself to select my summation words more carefully in future.<br /><br />That aside, still extremely interesting stuff. That the stack performs so flawlessly (relative speaking) every time out is an enduring testament to abilities of the American space program. I suspect we are going to be a long time missing such a multifunctional launch/space vehicle in the coming years.<br /><br />Shuttle really is ahead of its time in many respects in my view. <div class="Discussion_UserSignature"> <p><em><font size="2" color="#ff0000">Who is this superhero?  Henry, the mild-mannered janitor ... could be!</font></em></p><p><em><font size="2">-------------------------------------------------------------------------------------------</font></em></p><p><font size="5">Bring Back The Black!</font></p> </div>

 

[1cooldaddyo]

This explains something that happened with one of my daughter's model rockets. Its an Estes "Shuttle Express" that has 2 gliders hanging on eyelets on the side of the main body. These are supposed to be released during the coast phase. Using a B6 motor, this is exactly what happened. However when we stepped up to a larger C6 motor, one of the gliders separated about halfway through ascent and got whacked by the main body's fins. I had been wondering how an unpowered "piece" could get ahead of "the business end". That airflow is tricky stuff.

 

[shuttle_rtf]

Hi SG, hope you're well.<br /><br />To clarify....<br /><br />The reference to "confusion" was not about the debris, it was in reference to the IS&AG presentation which evaluated STS-116's "Thermal Curtain Stabilization" images and video.<br /><br />The article was about both the debris - which quotes Wayne Hale - and used to follow up my previous article on this, and the TCS, which it leads.<br /><br />The element of that article which is referenced here is:<br /><br />"Super high resolution video of STS-116's "Thermal Curtain Stabilization" shows what appears to be a large amount of flapping at the aft end of the left SRB, which continues to cause confusion as to exactly what was being observed." - reference to IS&AG presentation associated with it, which disagreed with initial finding, and notes 'confusion' on 'exactly' what is being observed.<br /><br />So I wasn't confused by Wayne Hale's comments, which were in reference to the debris (not the TCS): His comment was - quote - "surprising"<br /><br />"'We're going about four times the speed of sound, these little booster rockets are located some 30 feet lower, aft, down wind of the shuttle, and for a piece of insulation to come off sideways and travel upwards of 30 feet against a mach four air stream is just a little surprising"<br /><br />Thanks,<br />Chris.