Author Topic: SRB Q&A  (Read 56412 times)

Offline spacecane

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Re: SRB Q&A
« Reply #60 on: 05/04/2013 10:40 am »
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.

Offline Calphor

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Re: SRB Q&A
« Reply #61 on: 05/04/2013 02:12 pm »
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.

Offline spacecane

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Re: SRB Q&A
« Reply #62 on: 01/29/2014 01:11 pm »
What is (was) used to measure the chamber pressure and where was it located?

Offline Jim

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Re: SRB Q&A
« Reply #63 on: 01/29/2014 01:25 pm »
What is (was) used to measure the chamber pressure and where was it located?

Pressure transducers and they were located at the forward closure

Online AnalogMan

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Re: SRB Q&A
« Reply #64 on: 01/29/2014 04:36 pm »
What is (was) used to measure the chamber pressure and where was it located?

As Jim said above.

More info in this article:
http://www.nasaspaceflight.com/2008/11/sts-126-srb-modification-thrust-oscillation-data/

Datasheets for Stellar Technology Operational and Intelligent Pressure Transducers (OPT & IPT)

http://www.stellartech.com/whysti/hilitesheets/HL-OPT.pdf
http://www.stellartech.com/whysti/hilitesheets/HL-IPT.pdf

These work by measuring the strain induced in a flexible stainless steel diaphram using foil strain gauges.

Comparison of original OPTs and later versions supplied by Stellar attached.
« Last Edit: 01/29/2014 04:37 pm by AnalogMan »

Offline brad2007a

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Re: SRB Q&A
« Reply #65 on: 02/18/2015 05:53 pm »
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.
« Last Edit: 02/18/2015 05:57 pm by brad2007a »
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Offline Jim

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Re: SRB Q&A
« Reply #66 on: 02/18/2015 07:09 pm »
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.

Offline brad2007a

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Re: SRB Q&A
« Reply #67 on: 03/19/2015 09:23 pm »
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.
« Last Edit: 03/19/2015 09:24 pm by brad2007a »
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Offline Decius_Caecilius_Metellus

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SRB Q&A
« Reply #68 on: 05/03/2015 08:42 am »
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 :D   
« Last Edit: 05/03/2015 01:46 pm by Chris Bergin »
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Offline R7

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Re: SRB Q&A
« Reply #69 on: 05/06/2015 09:30 am »
http://en.wikipedia.org/wiki/Aluminium_oxide

Melting 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.

AD·ASTRA·ASTRORVM·GRATIA

Offline ClaytonBirchenough

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Re: SRB Q&A
« Reply #70 on: 07/06/2015 07:28 pm »
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!
Clayton Birchenough

Offline turbopumpfeedback2

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Re: SRB Q&A
« Reply #71 on: 12/25/2019 09:30 pm »
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?

« Last Edit: 12/25/2019 09:31 pm by turbopumpfeedback2 »

Offline Damon Hill

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Re: SRB Q&A
« Reply #72 on: 12/25/2019 10:03 pm »
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.

Offline turbopumpfeedback2

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Re: SRB Q&A
« Reply #73 on: 12/25/2019 10:15 pm »
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.

Offline TrevorMonty

Re: SRB Q&A
« Reply #74 on: 12/26/2019 03:28 pm »
SRBs are &gt;heavy&lt; 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.

Offline DaveS

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Re: SRB Q&A
« Reply #75 on: 11/09/2022 08:24 pm »
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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