sts-104 (bi108) flight readiness review program june · pdf filests-104 (bi108) flight...

STS-104 (BI108)

FLIGHT READINESS REVIEW

PROGRAM

June 28, 2001

Solid Rocket Booster

SRB-2

STS-104 FLIGHT READINESS REVIEW PROGRAMPresenter:

Roger ElliottOrganization/Date:

USA-SRB/6-28-01

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• Changes Since STS-100/BI107 – None to present• Nonconformances - None to present• Technical Issues

• BSM Residual Propellant

• Readiness Assessment• Certification Sheet

AGENDA

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Unburned Propellant

DOF

BSM Orientation on Pad

IFA #STS-100-B-01

Observation• Unburned propellant in RH Forward Booster Separation Motor

(BSM) S/N 3003009• Centered approximately 180 degrees from top dead center• Approximate measurement 100 degrees circumferentially and 1/3

length of BSM case axially

TECHNICAL ISSUE BSM RESIDUAL PROPELLANT

Unburned Propellant

BSM Igniter

BSM S/N 3003009

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Concern• Rupture, burn through or debris ejection

• Criticality 1

• Failure to ignite, low thrust, premature or delayed ignition• Criticality 1R

BSM Cluster Postflight PhotoBSM Cluster Closeout Photo


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BSM RESIDUAL PROPELLANTCause• Moisture contamination at launch pad

• Water intrusion through Aeroheat Shield (AHS) cover seal

Discussion• Failure Mechanism for incomplete BSM burn

• Ammonium Perchlorate (AP) leaches out of propellant • Burn rate slowed

• Ignition not accomplished in heavily soaked areas• Final extinguishment when case pressure drops below ~ 7 psia

• AHS Failure Modes• Improper cover seal configuration and installation• Improper frangible link configuration and installation

• Post-installation degradation (mechanical, chemical and environmental)

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Discussion (cont.)• Failure modes identified on Fault tree


R e ce iv ingIn sp e ction1 .2.3.1 .1 .1

S torage1 .2.3.1 .1 .2

O S F1 .2.3.1 .1

A R FD e live ry/S tag ing

1 .2.3.1 .2

P re -In stalla tion

1 .2 .3 .1

B S Min to Frus tum

1 .2 .3.2 .1

O p en G ra inInsp e ction1 .2 .3.2 .2

A H S a n d S e alIns talla tion

1 .2 .3.2 .3

L e a k C he ckA sse m b ly1 .2 .3.2 .4

C D F In it ia torIns talla tion

1 .2 .3.2 .5

In stalla t ion1 .2 .3 .2

A R F1 .2.3.3 .1

V AB1.2.3.3 .2

S ta ck1 .2.3.3 .3

L e ak T h ruN o zzle C lo su re

1 .2.3.3 .4 .1

W a te r LeakT h ru Ign ite r/Ig n ition T ra in

1 .2.3.3 .4 .2

L e a k Th ruA H S C o ver

P o rt P lug1 .2 .3.3 .4 .3

A sse m b lyT o lera nceS ta ck-up

1 .2 .3.3.4.4 .1 .1

C o ver S e alC o m pre ss ion

S et1 .2.3.3.4.4 .1 .2

D e sign1 .2 .3.3.4 .4 .1

C o m p one ntN o t to P rint

1 .2.3.3.4 .4 .2

In stalla tionIssues

1 .2.3.3.4 .4 .3

C o ve r S ealM a te ria l

C o m p ata b ility1 .2.3.3.4.4 .4 .1

P re -In sta lla tionP h ys ica lD a m a ge

1 .2.3.3.4.4 .4 .2

P o st-Ins talla tionP h ysica lD a m a ge

1 .2.3.3.4.4 .4 .3

E n viro n m e nt1 .2.3.3.4 .4 .4

L e a k Th ruA H S C o verA sse m b ly1 .2.3.3 .4 .4

L a un chP ad

1 .2.3.3 .4

P o st-In stalla tion

1 .2 .3 .3

S u rface C o nta m in a tion a t K SC1 .2 .3

In h ib it in g M a teria l on S urface1 .2

In hib ited Ig nit iona n d/o r Bu rnin g o f G ra in

1 .0

A n om a lo u s B S M M o tor B u rn0 .0

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SRB Forward AssemblyBSM Seals

(Aeroheat Shield Removed)

BSM Cluster


RTV 133

Frustum Skin Panel

RTV 102

RTV 102

Dual O-Rings

Dual O-Rings

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BSM RESIDUAL PROPELLANT

Booster Separation Motor Aeroheat Shield Assembly - Exploded View

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FSA0026


Frangible Link

Pawl

Hinge Pin

AA

RatchetBooster Separation Motor Aeroheat Shield

FSA0026

Frangible Link Cover Attach Holes (Installed at Vendor)

Frangible Link Screws (Installed at Vendor)

Cover Seal

BSM Nozzle Exit Cone

Aeroheat Shield Ring

Aeroheat Shield Cover

View A-ABSM Nozzle Added

(Frangible Link not shown)

Aeroheat Shield Installation Screws (ARF)

Strongback

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Discussion (cont.)• Cover seal compatibility testing with processing fluids used in

BSM area• Materials: DC-55 grease, Conoco grease, cleaning solvents, leak

detection fluid, buffer solution simulating pH of bird feces• No long term gross compatibility issues identified

• BSM Nozzle/AHS rain test• Fifty-two tests performed with 1200 in/hr water flow

• Nominal assemblies tested

• Incorrect installation and seal damage simulated and tested

• Damage after assembly simulated and tested

• Frangible link failure/slippage simulated and tested• Oversized and undersized conditions simulated and tested


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Polycarbonate Plug

Nozzle

Throat

Polycarbonate Plug

Nozzle

Throat

H2O Supply(40 Psig Min.)

Spray Nozzle

90º

45º

0º

20 IN.

AEROHEAT SHIELD / NOZZLE ASSY.

Direction of Spray

H2O Supply(40 Psig Min.)

Spray Nozzle

90º

45º

0º

20 IN.

AEROHEAT SHIELD / NOZZLE ASSY.

Direction of Spray

BSM Nozzle/AHS rain test (cont.)

TEST SETUP

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Discussion (cont.)• BSM Nozzle/AHS rain test (cont.)

• Test conclusions• No water leakage with Minor GN2 leaks (localized) • Very minor leakage into nozzle (if at all) with “kissing seal”

• Minimal, if any, seal compression)

• Gross leak or damage required for significant water entry• Simulated broken frangible link

• Three inches removed from upper leg of seal

• No seal installed

• Minor leak with loose frangible link bolts• Seals that pass GN2 test will not allow water leakage into nozzle


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Discussion (cont.)• Additional AHS testing performed in VAB 06-09-01

• Testing designed to address all failure modes

• Successfully performed on STS-104

Failure Mode Addressed

Test Title Test DetailsAcceptance

Criteria

STS-104 (BI108) Results

Proper Frangible Link Installation

High Pressure

Measure Strongback to Ring Distance; Apply +7.5 to +8.0 psi; Measure Strongback to

Ring Distance

Delta distance: +0.010 / -0.005

inch

Delta distance ≤ 0.002 inch

Low VacuumPressure Decay

Apply -0.5 to -1.0 psi; Perform 5 minute Decay Test

Mid-VacuumPressure Decay

Apply -4.5 to -5.0 psi; Perform 5 minute Decay Test

Mid-Positive Pressure Decay

Apply +4.5 to +5.0 psi; Perform 5 minute Decay Test

Positive Pressure Bubble Leak Test

Apply +4.5 to +5.0 psi; Perform bubble test

No Leaks No Leaks

Proper Frangible Link Installation

Final Cover Movement

Measure Strongback to RingDelta distance: +0.010 / -0.005

inch

Delta distance ≤ 0.003 inch

Proper Seal Installation and Post-Installation

Degradation

Pressure change ≤ 0.1 psid

No Pressure changes

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BSM RESIDUAL PROPELLANTRationale for Flight• STS-104 BSMs inspected at receiving and prior to AHS

installation and verified dry• AHS seals passed pressure leak test in ARF• M&P analysis and testing confirm AHS seals remain functional

after exposure to known contaminants• AHS testing demonstrates robust AHS design • System margins allow for loss of one forward BSM’s thrust per

SRB at separation• Integrity of AHS and cover seals reconfirmed

• Inspected and leak tested in VAB (5-10-01) 10 months after ARF inspection and test

• Additional extended testing successfully completed 6-09-01 refuting all identified failure modes

• STS-104 is safe to fly

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• Pending completion of open work, there are no constraints to launch for STS-104

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11CERTIFICATION SHEET

sts-104 (bi108) flight readiness review program june · pdf filests-104 (bi108) flight...

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