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SRB Q&A
by
Gambina-GSFC
on 10 Sep, 2009 18:28
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I am trying to figure out "exactly" how the SRB forward attachment works. I realize it is a ball and socket joint which releases upon detonation of the NSD's, but I have had almost no luck in getting a picture/drawing of a fully exposed forward attachment fitting on either the SRB nor the ET. Any help would be greatly appreciated.
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#1
by
Jim
on 10 Sep, 2009 19:08
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The socket is in the green fixture and the ball is underneath it
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#2
by
Chris Bergin
on 10 Sep, 2009 19:12
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Welcome to the site's forum.
We're bound to have some graphics in the SRB "bibles" in L2 (which - given you're NASA - you get free access to.....I'll message you the details). But it'd be good to be able to screenshot some of what's being asked into here for all.
So if any of our L2 members have a spare moment, feel free to add some screenshots from the L2 presentations into this thread, which we'll make a SRB Q&A while we're at it.
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#3
by
AnalogMan
on 10 Sep, 2009 19:31
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...
So if any of our L2 members have a spare moment, feel free to add some screenshots from the L2 presentations into this thread, which we'll make a SRB Q&A while we're at it.
A couple of grabs from the Shuttle SLWT System Definition Handbook which we have in 3 parts in the public section (thanks to Fequalsma). Its in three parts and can be found here:
http://forum.nasaspaceflight.com/index.php?topic=14350.0
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#4
by
Danny Dot
on 10 Sep, 2009 19:56
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Doesn't look like a ball and socket to me? Does it allow for any rotations?
Maybe it becomes a ball and socket when the bolt is "removed" with the pyros to allow it to rotate as it separates.
Danny Deger
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#5
by
AnalogMan
on 10 Sep, 2009 22:19
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Doesn't look like a ball and socket to me? Does it allow for any rotations?
Maybe it becomes a ball and socket when the bolt is "removed" with the pyros to allow it to rotate as it separates.
Danny Deger
It is just a spherical bearing surface, rather than a fully articulated "ball and socket" fitting - I guess it just allows for minor angular misalignments between the ET thrust beam end and the SRB brackets during assembly. This is similar to the spherical bearing used on the hold-down posts at the aft skirt and MLP.
(modified drawing attached to highlight the SRB/bolt/ET interface)
Edit: Thinking about it, this bearing surface may accommodate the small amount of flexure in the ET beam under the thrust load of the SRM.
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#6
by
TyMoore
on 11 Sep, 2009 17:57
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Edit: Thinking about it, this bearing surface may accommodate the small amount of flexure in the ET beam under the thrust load of the SRM.
That's exactly what it does. It allows small angular flexures in the structure which reduces shearing stress in the bolt--no flexure, broken bolt--LOV and LOC.
Criticality 1 failure!
Thanks for the diagrams AnalogMan---they actually answer some questions I had regarding my own little project. Thanks!
Ty Moore
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#7
by
AnalogMan
on 11 Sep, 2009 23:02
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TyMoore: thanks for confirming my thoughts on the spherical bearing surface - as for the diagrams, glad to be able to help on your project.
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#8
by
nunikasi
on 20 Sep, 2009 09:51
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Hi.
So I was watching this video on Youtube, showing the Ares l Solid Rocket Test, and I wonder, before the launch, when the man says "and here is the sound of the high speed camera", how can high speed cameras make such a weird sound?
I thought hsc's were not making wierd sounds.
So what is that sound?
Heres the video and the time is 0:42
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#9
by
Jim
on 20 Sep, 2009 10:04
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No need for an Q&A thread on this
The sound is the film reels in the cameras spinning up
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#10
by
eeergo
on 20 Sep, 2009 16:45
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Not trying to get this thread too big, but I was bugged by this same sound when I heard it... it just after the mentioned spinning sound, a chugging sound appears, and there's some TVC movement. Can it be the whirring is actually caused by the HPU starting up, and it just coincides in time with the hi-speed camera activation?
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#11
by
TyMoore
on 21 Sep, 2009 04:20
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I dunno--but a definate "could be."
That was an impressive mushroom cloud of dust and smoke--probably visible from space, I'd imagine.
Thanks for posting the video.
I would have loved to have been there in person--I'll bet the 'boom' of motor ignition came as an almost seismic shock to the folks viewing, what about two miles away?
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#12
by
AlexInOklahoma
on 21 Sep, 2009 13:28
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No need for an Q&A thread on this
The sound is the film reels in the cameras spinning up
As Jim says, the whirring/whining is from the cameras spinning-up. A quote from a quick googling
http://people.rit.edu/andpph/text-teaching-high-speed-photo/index.html -> "and students are enthralled still by the whine of a high speed motion picture camera reaching its peak framing rate" There's some really, really fast-moving stuff inside those cameras ;-)
'Nuff said?
Alex
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#13
by
MKremer
on 22 Sep, 2009 22:15
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No need for an Q&A thread on this
The sound is the film reels in the cameras spinning up
I thought it might be the APU startup, but that's at around 28 seconds or so.
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#14
by
DaveS
on 24 Sep, 2009 23:24
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No need for an Q&A thread on this
The sound is the film reels in the cameras spinning up
I thought it might be the APU startup, but that's at around 28 seconds or so.
Well, if you listen closely, you can hear the spin-up is followed by a very distinct chugging sound. Where have we heard that before?
Oh yes, from the orbiter APUs once they have been started. They too emit an spin up sound at start up and chugging sound once they have reached a stable pressure.
And they do generate a spin down sound when they're shut down on the runway.
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#15
by
sdsds
on 07 Feb, 2010 04:17
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It's been mentioned that a stacked SRB has a limited shelf life, i.e. it cannot be held indefinitely and then launched safely. What are the limits for this? Specifically, if STS-335 is stacked on schedule and not used, can the stack be held dormant for months? Years?
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#16
by
joncz
on 08 Feb, 2010 23:55
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If you are standing directly below the MLP while it is still in the VAB, can you shine a flashlight up into the SRB and see up into flame path in the booster? If so, are there any pics?
See
http://forum.nasaspaceflight.com/index.php?topic=641.0 for a video of SRB ignition looking up into the SRB.
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#17
by
JayP
on 14 Feb, 2010 18:46
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If you are standing directly below the MLP while it is still in the VAB, can you shine a flashlight up into the SRB and see up into flame path in the booster? If so, are there any pics?
No, there is a foam plug bonded in the nozzle throat that would block your view.
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#18
by
dgates
on 15 Feb, 2010 00:49
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Maybe this is a better place for this question: Why recover the remaining SRB's if they won't be reused in the future as the Shuttle program winds down?
If they are declared expendables, then can the recovery hardware be removed to save weight? Like, remove the parachutes and just let them splash and sink? I suppose there could be vehicle dynamics implications and CG implications, but just a thought....
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#19
by
Jorge
on 15 Feb, 2010 00:53
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Maybe this is a better place for this question: Why recover the remaining SRB's if they won't be reused in the future as the Shuttle program winds down?
If they are declared expendables, then can the recovery hardware be removed to save weight? Like, remove the parachutes and just let them splash and sink? I suppose there could be vehicle dynamics implications and CG implications, but just a thought....
No. See my answer in the shuttle Q&A thread.
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#20
by
JayP
on 26 May, 2010 17:13
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This maybe a strange question, but how do the spent SRM segments start on their trip back to Utah? I know that they are washed and dissasembled at Hanger AF and that they end up in the same rail cars they are delivered in, but how do they get from one to the other. There are no railroad tracks out to the cape industrial area. Do they use the KAMAG transporters that move them from the RPSF to the VAB or something else?
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#21
by
Jim
on 26 May, 2010 18:12
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They are trucked from Hangar AF to a rail siding which is between Kennedy Parkway and Contractor Road, which is south of the VAB.
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#22
by
JosephB
on 12 Jul, 2010 20:02
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You know, I've gotten fired up about the 1.7 - 2 million Lb thrust staged combustion kerolox engine talk but these SRB's are pretty impressive.
Not to mention the potential of the HTPB 5 seg composite motor (4.7 million lb)(page 5 of attached study).
Anyone care to take a stab at the pros & cons of SRB vs. kerolox booster for a layperson like myself? Thanks.
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#23
by
Gambina-GSFC
on 02 Sep, 2010 15:01
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I am looking for SRB drawings, just trying to figure out how the load is transferred from the booster to the ET attachment point. The SRB just seems like a big casing with the solid fuel in the middle. Therefore, the load must be applied through the casing into the ET attachment point. I wam very interested on how the SRB is structurally built.
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#24
by
Jim
on 02 Sep, 2010 15:25
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I am looking for SRB drawings, just trying to figure out how the load is transferred from the booster to the ET attachment point. The SRB just seems like a big casing with the solid fuel in the middle. Therefore, the load must be applied through the casing into the ET attachment point. I wam very interested on how the SRB is structurally built.
The casing is the structure and it is nothing more than a cylinder.
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#25
by
JayP
on 02 Sep, 2010 20:25
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I am looking for SRB drawings, just trying to figure out how the load is transferred from the booster to the ET attachment point. The SRB just seems like a big casing with the solid fuel in the middle. Therefore, the load must be applied through the casing into the ET attachment point. I wam very interested on how the SRB is structurally built.
The vertical load is transfered from the top edge of the case to the bottom of the forward skirt. Milled panels on the skirt direct the load to the ET attach fitting on the side of the skirt next to the ET. the fitting protruded from the side of the skirt and fits under the end of the ET crossbeam (which sticks out from the side of the intertank). the loads go into the beam and are redistributed to teh rest of the tank structure by the intertank panels.
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#26
by
AnalogMan
on 02 Sep, 2010 23:54
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To add a little to JayP's post - this is a description of the structure (taken from an L2 document)
The forward skirt, 146 inches in diameter and 125 inches long, consists of a 2219 aluminum welded cylinder assembly made from precision-machined and brake-formed skin panels and a welded thrust post subassembly weighing approximately 5700 lb. Welded to this are the forward ring, RSRM attach ring, intermediate rings, gussets, beams, etc. The skirt is then artificially aged and machine finished.A second older source (from 1981) describes the skin panels as varying in thickness from 0.5 to 2 inches.
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#27
by
chriswhitty1
on 31 Jan, 2011 11:38
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hello
Cool forum! I was wondering how the fuel segments are attached to the wall of the srb sections.
I think there is a space between each segment when the srb is assembled.
What stops the fuel segment from moving inside the cylindrical housing when it fires?
cheers
Chris
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#28
by
Jim
on 31 Jan, 2011 11:42
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hello
Cool forum! I was wondering how the fuel segments are attached to the wall of the srb sections.
I think there is a space between each segment when the srb is assembled.
What stops the fuel segment from moving inside the cylindrical housing when it fires?
cheers
Chris
The propellant is poured into the segment metal casing and then is "cured" (hardens). So the propellant adheres to the side the casing.
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#29
by
Mark Dave
on 31 Jan, 2011 19:42
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There was a segment shown on Extreme Machines that showed the molding of the propellant for the SRBs years ago.
Since each segment is filled one by one, is there a filler to prevent gaps between the propellant molds?
Why was the insta-foam added to the lowest segment of each SRB? Earlier flights never had this.
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#30
by
Jim
on 31 Jan, 2011 23:23
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There was a segment shown on Extreme Machines that showed the molding of the propellant for the SRBs years ago.
Since each segment is filled one by one, is there a filler to prevent gaps between the propellant molds?
Why was the insta-foam added to the lowest segment of each SRB? Earlier flights never had this.
there is insulation between segments
The foam was added for thermal and splash down protection.
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#31
by
Prober
on 28 Dec, 2011 17:27
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#32
by
JayP
on 28 Dec, 2011 17:34
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thought I might port this thread to get more ideas & answers.
Horizontal assembly of the SRB, might be a better way to go? Any ATK people around? Do you assemble the test boosters horizontally?
http://forum.nasaspaceflight.com/index.php?topic=27613.30
The problem is erecting a single unit weighing more than 1 million pounds. It has been discussed many times in reference to monolithic motors.
Obviously, if your going to fire the motor horizontally (as ATK does in Utah) thats not a concern, but it doesn't help you with a launch vehicle.
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#33
by
wolfpack
on 28 Dec, 2011 17:41
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thought I might port this thread to get more ideas & answers.
Horizontal assembly of the SRB, might be a better way to go? Any ATK people around? Do you assemble the test boosters horizontally?
http://forum.nasaspaceflight.com/index.php?topic=27613.30
I don't think you'd be able to lift them into the vertical after horizontal assembly without significant risk that the seals between segments would be compromised. I recall that after Challenger, there was some concern that the turn on the crawlerway to pad 39B might have introduced a torque moment that was thought to possibly have compromised a seal. Disproven later, of course.
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#34
by
Mark Dave
on 30 Dec, 2011 23:42
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Are there any photos showing the SRB/ET attach ring modification being added after STS-51L so STS-26R can launch?
What are these bands that partly wrap around the SRBs? You can see them on the aft side of the right SRB in this photo and partly on the forward side.
http://www-pao.ksc.nasa.gov/kscpao/images/large/2011-5359.jpg
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#35
by
JayP
on 30 Dec, 2011 23:55
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#36
by
Mark Dave
on 31 Dec, 2011 19:13
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I see.
I only noticed these on the boosters following STS-26R. Before that there weren't any on the boosters. Why? I mean after STS-51L they were added. Was this part of the RTF changes?
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#37
by
Mark Dave
on 06 Jan, 2012 13:06
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How are the SRBs stacked for the tests in Utah? Are the boosters stacked as usual and then laid down or are they assembled in the horizontal?
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#38
by
Jim
on 06 Jan, 2012 13:09
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Everything horizontal.
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#39
by
wolfpack
on 06 Jan, 2012 13:58
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How are the SRBs stacked for the tests in Utah? Are the boosters stacked as usual and then laid down or are they assembled in the horizontal?
Yep, horizontal. One of the major criticisms in the Rogers report. RTF demo and qual motors were still done horizontally, but they had to add hydraulic jacks to simulate flight loads while firing.
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#40
by
Mark Dave
on 10 Jan, 2012 00:32
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Are there any close ups of the strain gauge straps that are on the SRBs? I notice in some photos there is a sort of sign or logo above the ends of each strap. What does it say?
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#41
by
JayP
on 10 Jan, 2012 01:20
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Are there any close ups of the strain gauge straps that are on the SRBs? I notice in some photos there is a sort of sign or logo above the ends of each strap. What does it say?
Here is one of the booster being towed in. If you zoom in you can see that the label reads "B06T7007A L.H. / B06T8007A R.H." I assume that refers to the drawing number of the individual installations.
Edit - Here is another photo of 3 of the 4 installations down this side of this booster.
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#42
by
spacecane
on 08 Mar, 2012 05:10
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How do the O-rings manage to actually work? I understand that if you just had a pressurized cylinder filled with air or something that the force on the O-rings creates a seal (like in a plumbing application). What I am having trouble understanding is how the rubber doesn't melt. I assume it doesn't burn because there is no oxygen present at the side that gets hot.
Maybe I'm misunderstanding the joints and hot gasses don't touch the rubber but then in that case why did the pre 51-L design have hot gas blow by (and then failure)?
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#43
by
Jim
on 08 Mar, 2012 13:05
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How do the O-rings manage to actually work? I understand that if you just had a pressurized cylinder filled with air or something that the force on the O-rings creates a seal (like in a plumbing application). What I am having trouble understanding is how the rubber doesn't melt. I assume it doesn't burn because there is no oxygen present at the side that gets hot.
Maybe I'm misunderstanding the joints and hot gasses don't touch the rubber but then in that case why did the pre 51-L design have hot gas blow by (and then failure)?
There was asbestos putty that was to protect the rings, the blow by was from gases penetrating the putty.
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#44
by
zeke01
on 08 Mar, 2012 13:45
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How do the O-rings manage to actually work? I understand that if you just had a pressurized cylinder filled with air or something that the force on the O-rings creates a seal (like in a plumbing application). What I am having trouble understanding is how the rubber doesn't melt. I assume it doesn't burn because there is no oxygen present at the side that gets hot.
Maybe I'm misunderstanding the joints and hot gasses don't touch the rubber but then in that case why did the pre 51-L design have hot gas blow by (and then failure)?
There was asbestos putty that was to protect the rings, the blow by was from gases penetrating the putty.
The putty had channels in them due to a leak check that blew pressurized air between the o-rings during stacking. So when the motor fired, the hot gasses had a direct path to the o-rings. This is described in the Rogers report.
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#45
by
DMeader
on 08 Mar, 2012 14:47
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In the re-designed field joint, the putty has been replaced by a rubber flap (called J-leg) that is sealed by the pressure in the casing. More pressure, better seal.
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#46
by
OV135
on 22 Oct, 2012 13:39
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#47
by
Jim
on 22 Oct, 2012 14:39
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#48
by
JAFO
on 19 Feb, 2013 02:46
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Can someone please explain the difference between the 4 seg STS and 5 seg SLS SRB, please? I've heard it said that production of the 4 seg was no longer possible, trying to figure out what the differences are.
TIA
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#49
by
wkann
on 19 Feb, 2013 03:21
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Can someone please explain the difference between the 4 seg STS and 5 seg SLS SRB, please? I've heard it said that production of the 4 seg was no longer possible, trying to figure out what the differences are.
TIA
I alway thought that a 4 seg vs 5 seg SRB was that the 5 seg SRB could lift more weight to orbit. And of course, it has an extra segment for more propellant.
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#50
by
padrat
on 19 Feb, 2013 03:38
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I believe the grain pattern is different as well.....
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#51
by
Calphor
on 19 Feb, 2013 04:05
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The major difference between the two is the additional segment
(I know that is too obvious) added in the middle. The RSRM consisted of the forward, center forward, center aft and aft segments. The 5 segment consists of a forward, center forward, center center (I'm not making this up...), center aft and aft segments. As padrat mentioned there are design tweaks between the two booster grains. The forward segment on RSRM had 11 fins, where as the 5 seg has 12. The 5 seg has some additional chamfer on the forward portion of the bore of the aft 4 segments. The throat diameter is larger for the 5 seg to keep the chamber pressure within case limits. The ablative materials in the nozzle have been altered to deal with the increased mass flow rates. There has been additional length added to the exit cone to regain some of the expansion ratio lost by increasing the throat diameter.
One of the major reasons that RSRM cannot be produced any longer is that the original shuttle requirements called for using a hydroclave to produce the ablative materials for the nozzle. That piece of equipment was decommissioned at the end of the Shuttle program. Also, some of the tooling and hardware was stored or disposed of at program end. Could ATK make a booster that looks the same and has similar performance to RSRM? Sure, given sufficient time and $, but it probably would not be the same as RSRM because of the above issues.
I could continue on, but at some point I would hit the ugly ITAR restrictions and no one wants to see that happen (especially me!). Suffice it to say that there has been significant updating since the idea (5 segment booster) was first tried back in 2003 (ETM-3).
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#52
by
AnalogMan
on 19 Feb, 2013 11:15
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Can someone please explain the difference between the 4 seg STS and 5 seg SLS SRB, please? I've heard it said that production of the 4 seg was no longer possible, trying to figure out what the differences are.
This is from a 2011 paper which gives some details of differences between Shuttle RSRM and Constellation RSRMV (which will also be used for the first two SLS flights):
Modifications to the RSRM design were made to improve performance (thrust), eliminate hazardous materials and replace obsolete materials. Changes from the RSRM are shown [in diagram below] and included:
(1) increasing the number of center segments from two to three,
(2) increasing the number of propellant fins in the forward segment from 11 to 12,
(3) the addition of forward chamfers on center and aft segments,
(4) lowering the propellant burn rate
(5) modification of the propellant inhibitor heights and thicknesses,
(6) increasing the nozzle throat diameter,
(7) extending the nozzle exit cone,
(8) modifying insulation and liner formulations to eliminate Chrysotile fibers, and
(9) modifying the insulation lay-up to increase thermal protection.Note: ETM-3 is an early version of a 5-segment motor that was test fired in 2003.
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#53
by
OV135
on 23 Feb, 2013 22:06
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#54
by
RyanC
on 06 Mar, 2013 05:24
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What would happen if you scaled down a solid rocket motor in every dimension by say 25% (or 50%), and kept all of the basic ratios intact?
Would it perform mostly the same as it's larger version, but with less thrust? [how much less]?
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#55
by
spacecane
on 06 Mar, 2013 12:32
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Are the RSRMVs used for SLS planned to be recovered/"reused"? I put "reused" in quotes since for Shuttle with all the processing required I think it was more like "recyled".
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#56
by
Jim
on 06 Mar, 2013 13:45
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Are the RSRMVs used for SLS planned to be recovered/"reused"? I put "reused" in quotes since for Shuttle with all the processing required I think it was more like "recyled".
no
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#57
by
brad2007a
on 28 Mar, 2013 00:39
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I have a couple of SRB questions that may have been answered elsewhere, possibly in the Shuttle Q&A sections, but these have become quite large, and exhausting to look through (although very interesting, of course.) So if they have been, please point me to the appropriate sections. Anyway, here goes:
These are about possible SRB "nightmare" scenarios during a Shuttle launch, other than the one that befell Challenger 51L. Thankfully none of these scenarios happened, but the reason I ask these questions is because I've heard or read so many conflicting stories about what would've happened in these cases. I'm no expert, so I thought I'd ask the experts here...
1. One SRB ignites, the other does not: I've heard and read the stories about how, should this have happened, the Shuttle would've "cartwheeled" either into the FSS, or the nearby swamps. True or false?
2. At SRB sep, the bolts on both boosters blow, but on, say, one of the boosters the separation motors fail to ignite: How much danger was there of the SRB falling into the orbiter or ET, or was there enough clearance (given the orbiter and ET's velocity at that point) for it to (barely) miss the vehicle?
3. One or both boosters fail to separate: I understand that there was no way for the Shuttle to make orbit with the dead weight of one or both SRB casings, so it would have been an abort (RTLS or contingency), but what would be the likelihood of successfully flipping the vehicle over (as in an RTLS) with the booster(s) still attached?
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#58
by
Jim
on 28 Mar, 2013 02:56
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1. One SRB ignites, the other does not: I've heard and read the stories about how, should this have happened, the Shuttle would've "cartwheeled" either into the FSS, or the nearby swamps. True or false?
2. At SRB sep, the bolts on both boosters blow, but on, say, one of the boosters the separation motors fail to ignite: How much danger was there of the SRB falling into the orbiter or ET, or was there enough clearance (given the orbiter and ET's velocity at that point) for it to (barely) miss the vehicle?
3. One or both boosters fail to separate: I understand that there was no way for the Shuttle to make orbit with the dead weight of one or both SRB casings, so it would have been an abort (RTLS or contingency), but what would be the likelihood of successfully flipping the vehicle over (as in an RTLS) with the booster(s) still attached?
1. true
2. It likely would be LOC
3. no likelyhood
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#59
by
wolfpack
on 28 Mar, 2013 15:06
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I have a couple of SRB questions that may have been answered elsewhere, possibly in the Shuttle Q&A sections, but these have become quite large, and exhausting to look through (although very interesting, of course.) So if they have been, please point me to the appropriate sections. Anyway, here goes:
These are about possible SRB "nightmare" scenarios during a Shuttle launch, other than the one that befell Challenger 51L. Thankfully none of these scenarios happened, but the reason I ask these questions is because I've heard or read so many conflicting stories about what would've happened in these cases. I'm no expert, so I thought I'd ask the experts here...
1. One SRB ignites, the other does not: I've heard and read the stories about how, should this have happened, the Shuttle would've "cartwheeled" either into the FSS, or the nearby swamps. True or false?
2. At SRB sep, the bolts on both boosters blow, but on, say, one of the boosters the separation motors fail to ignite: How much danger was there of the SRB falling into the orbiter or ET, or was there enough clearance (given the orbiter and ET's velocity at that point) for it to (barely) miss the vehicle?
3. One or both boosters fail to separate: I understand that there was no way for the Shuttle to make orbit with the dead weight of one or both SRB casings, so it would have been an abort (RTLS or contingency), but what would be the likelihood of successfully flipping the vehicle over (as in an RTLS) with the booster(s) still attached?
Of those, 3 was the most likely. PASS had a bug where it was possible for the ARM/FIRE1/FIRE2 commands to the booster separation motors to not occur in the same timeslice (my word for lack of a better term), and the BSMs would have failed to fire. Additionally, PASS would have disconnected power to the PICs in the BSMs before BFS could have been engaged to attempt separation. I believe all of this was demonstrated on the ground. Several missions flew with this anomaly.
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#60
by
spacecane
on 04 May, 2013 10:40
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Does anybody know how many lumens the Shuttle SRB plumes put out? Obviously it was a lot but I'm curious if somebody knows the actual number.
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#61
by
Calphor
on 04 May, 2013 14:12
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I don't know if that number has ever been calculated or measured. I do know that the last night static test of an RSRM was easily visible in Salt Lake City which is over 80 miles away. It is also very uncomfortable to look at the plume from a mile away with sunglasses on.
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#62
by
spacecane
on 29 Jan, 2014 13:11
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What is (was) used to measure the chamber pressure and where was it located?
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#63
by
Jim
on 29 Jan, 2014 13:25
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What is (was) used to measure the chamber pressure and where was it located?
Pressure transducers and they were located at the forward closure
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#64
by
AnalogMan
on 29 Jan, 2014 16:36
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#65
by
brad2007a
on 18 Feb, 2015 17:53
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I have Filament Wound Case (FWC) SRB (the ones for Vandenburgh that were cancelled after Challenger) questions:
1. Was the cancellation of the FWC boosters an overreaction? If so, why? Didn't they have the field joint capture feature (among other elements) of the post-Challenger steel SRB design?
2. Could they have been used for KSC launches? Could they have replaced the heavier steel SRBs altogether?
3. If the answer to the first part of question 2 is "yes", would the weight savings inherent in the FWC SRB design have been enough to allow the use of Columbia for ISS construction missions (she was considered too heavy for these missions, otherwise)?
Thanks.
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#66
by
Jim
on 18 Feb, 2015 19:09
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I have Filament Wound Case (FWC) SRB (the ones for Vandenburgh that were cancelled after Challenger) questions:
1. Was the cancellation of the FWC boosters an overreaction? If so, why? Didn't they have the field joint capture feature (among other elements) of the post-Challenger steel SRB design?
2. Could they have been used for KSC launches? Could they have replaced the heavier steel SRBs altogether?
3. If the answer to the first part of question 2 is "yes", would the weight savings inherent in the FWC SRB design have been enough to allow the use of Columbia for ISS construction missions (she was considered too heavy for these missions, otherwise)?
Thanks.
1. No, there were other concerns
2. There were issues with the flexibility of the motors and the MLP's
3. The SLWT took care of the weight issue.
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#67
by
brad2007a
on 19 Mar, 2015 21:23
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I have Filament Wound Case (FWC) SRB (the ones for Vandenburgh that were cancelled after Challenger) questions:
1. Was the cancellation of the FWC boosters an overreaction? If so, why? Didn't they have the field joint capture feature (among other elements) of the post-Challenger steel SRB design?
2. Could they have been used for KSC launches? Could they have replaced the heavier steel SRBs altogether?
3. If the answer to the first part of question 2 is "yes", would the weight savings inherent in the FWC SRB design have been enough to allow the use of Columbia for ISS construction missions (she was considered too heavy for these missions, otherwise)?
Thanks.
1. No, there were other concerns
2. There were issues with the flexibility of the motors and the MLP's
3. The SLWT took care of the weight issue.
Thanks for the reply, Jim (sorry it took so long, but it has been a very rough, trying month...).
Anyway, I was wondering if you (or anyone else) could expand on a couple of your points:
1. You pointed out that there were other concerns. What were they (other than the KSC MLP issues)?
2. I understand that the SLWT ET took care of some of the weight issues, but I also thought that Columbia was still too heavy for ISS construction missions (her next flight after 107 was to have been an ISS resupply mission, not a construction one if I remember correctly). Am I wrong?
Thanks again.
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#68
by
Decius_Caecilius_Metellus
on 03 May, 2015 08:42
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I have been wondering if the Al2O3 produced in SRB combustion is gaseous in the nozzle and therefore contributes to expansion, because Al2O3 makes up such a large part of the exhaust that this would have a big impact on efficiency.
I hope that this is the right thread for this
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#69
by
R7
on 06 May, 2015 09:30
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http://en.wikipedia.org/wiki/Aluminium_oxideMelting point 2,072 °C (3,762 °F; 2,345 K)
Boiling point 2,977 °C (5,391 °F; 3,250 K)
The temperature at throat is somewhere near melting point but well below boiling point. Temperature at nozzle exit is below melting point. The Al2O3 particles are rejecting heat to the gaseous species, it depends on the particle size whether it happens quickly enough for the liquid particle to solidify while still inside the nozzle.
But gaseous, no, only trace amounts if any.
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#70
by
ClaytonBirchenough
on 06 Jul, 2015 19:28
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Does anyone have any detailed cost analysis's of the SRB propellant?
I guess I'm really just looking to see if anyone has any price estimates for producing solid rocket propellant. Maybe $/kg?
In addition, any info on the selection process of PBAN-APCP as propellant would be greatly appreciated. Were there any other propellants that were considered?
Also, any detailed information regarding the whole propellant making process (I think there's a better name for "propellant making process" but can't remember it ATM haha) of the SRB's propellant and all SRBs in general. TIA!
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#71
by
turbopumpfeedback2
on 25 Dec, 2019 21:30
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How do the SRBs contain the pressure?
Liquid fuel pressure fed engines are not good as then the tanks become heavy. Are the SRBs any better than pressure fed liquid fuel engines, since then the thank has to contain the pressure?
The solid rocket fuel does provide some tensile strength, but as the fuel is depleted the SRB hull must be able to withstand the pressure.
TLDR Are SRBs better than pressure fed liquid fuel rockets?
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#72
by
Damon Hill
on 25 Dec, 2019 22:03
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SRBs are >heavy< because they're very high pressure and major structural elements of the Shuttle stack. They're mostly made of maraging steel for its very high strength and somewhat for temperature tolerance.
Pressure fed liquid propellant tanks are almost lightweight by comparison, but hardly balloon tanks like Atlas was and Centaur is.
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#73
by
turbopumpfeedback2
on 25 Dec, 2019 22:15
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SRBs are >heavy< because they're very high pressure and major structural elements of the Shuttle stack. They're mostly made of maraging steel for its very high strength and somewhat for temperature tolerance.
Pressure fed liquid propellant tanks are almost lightweight by comparison, but hardly balloon tanks like Atlas was and Centaur is.
SRBs still have a very good dv, around 4.5 km/s (total mass 590 tons, fuel 500 tons, wikipedia). So a three stage rocket with SRB mass fraction would reach orbit. That's pretty good.
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#74
by
TrevorMonty
on 26 Dec, 2019 15:28
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SRBs are >heavy< because they're very high pressure and major structural elements of the Shuttle stack. They're mostly made of maraging steel for its very high strength and somewhat for temperature tolerance.
Pressure fed liquid propellant tanks are almost lightweight by comparison, but hardly balloon tanks like Atlas was and Centaur is.
SRBs still have a very good dv, around 4.5 km/s (total mass 590 tons, fuel 500 tons, wikipedia). So a three stage rocket with SRB mass fraction would reach orbit. That's pretty good.
The dry mass should be less on new composite case SRBs being used on Omega.
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#75
by
DaveS
on 09 Nov, 2022 20:24
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Since the question keeps coming up in relation to the SLS SRBs, what is the longest any SRM has been stacked be it shuttle or Titan which also used segmented SRMs? Those Titans, especially the IV-A and IV-B were notorious pad sitters, so they got have racked up some serious stack clock time and AFAIK, none of the SRM caused failures were ever traced to the "shelf life".
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#76
by
JAFO
on 15 May, 2024 18:06
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Reading Challenger by Adam Higginbotham, learning about the putty.
-This never occurred to me, but when the segments were assembled was there putty put between the solid fuel in each segment (like frosting between cake layers) so there was no room between the fueled segments? It seems like it would have to be, or there would be a gap where flame could reach the casing.
-If not, was there any gap between the fueled segments?
TIA
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#77
by
Jim
on 15 May, 2024 21:15
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Reading Challenger by Adam Higginbotham, learning about the putty.
-This never occurred to me, but when the segments were assembled was there putty put between the solid fuel in each segment (like frosting between cake layers) so there was no room between the fueled segments? It seems like it would have to be, or there would be a gap where flame could reach the casing.
-If not, was there any gap between the fueled segments?
TIA
After Challenger, it was insulation and there was the "J" slit in the insulation.
(I know that is too obvious) added in the middle. The RSRM consisted of the forward, center forward, center aft and aft segments. The 5 segment consists of a forward, center forward, center center (I'm not making this up...), center aft and aft segments. As padrat mentioned there are design tweaks between the two booster grains. The forward segment on RSRM had 11 fins, where as the 5 seg has 12. The 5 seg has some additional chamfer on the forward portion of the bore of the aft 4 segments. The throat diameter is larger for the 5 seg to keep the chamber pressure within case limits. The ablative materials in the nozzle have been altered to deal with the increased mass flow rates. There has been additional length added to the exit cone to regain some of the expansion ratio lost by increasing the throat diameter. 