srb processing

SPACE SHUTTLE PROGRAMSolid Rocket Booster ProcessingNASA Kennedy Space Center, Florida

Solid Rocket Booster Processing

Kennedy Space Center

SRB Mechanical Engineering

NE-M7


Shuttle Processing and Launch

Postflight Hardware Recovery

and Evaluation

KSC – Solid Rocket Booster (SRB) Processing Areas


KSC – Solid Rocket Booster (SRB) Processing Areas

RPSF

VABPad


SHUTTLELANDING

SRB RETRIEVALSHIP

HANGAR AF

RPSF

SRB STACKING

ET/SRBOPERATIONS

ETSTANDALONE

LCC

INTEGRATEDVEHICLE OPS/VAB

OffloadBuildup

HORIZONTALPAYLOAD INT

PAYLOAD FACILITIESHYPERGOLIC

FACILITY

ORBITER PROCESSINGFACILITY

Pad Ops

VERTICAL PAYLOAD INSTALLATION

Design Centers Element Refurbishment and Manufacturing Logistics and Shipping

Delivery

Offload and Inspect

Aft Booster Build

Field Joint Mate

Leak Test

Field Joint Protection System

S&A

Launch

Recovery

Disassembly and Assessment

KSC – Solid Rocket Booster (SRB) Processing Flow


Forward Assembly and Aft Skirt arrive from SRB Element in the Assembly Refurbishment Facility (ARF) at KSC.

ARFAft Skirt Parachutes

Nose Cone

Frustum

Forward Assembly

•Nose Cone

•Frustum

•Parachutes

•Forward Skirt


Segments arrive from ATK in Corrine, Utah in rail cars. The segments go to the Rotation, Processing and Surge Facility (RPSF) at KSC.

RPSF


At the Rotation, Processing and Surge Facility (RPSF), the rail cover is removed, propellant grain & metal surfaces inspected, the segments are rotated to vertical, secured on a pallet and stored in the surge facilities.

Break-over of the forward segment from horizontal to vertical


Aft Segment Breakover to

Vertical

AEC BreakoverAft Skirt Mate

AEC Mate

Build-up to Aft Booster

Configuration (see following charts)

Aft Booster Build-up Stand

At the RPSF, the aft booster is assembled and processed in the build-up stands. Other hardware processed in the RPSF includes:

- Stiffener Rings Assembly and Closeouts- Thermal Curtains- External Tank Assembly (ETA) ring and hardware- Thermal Protection System (TPS) closeouts- Systems tunnel and cables installation and closeouts- Heater power cable installation- Nozzle severance cable connection


Aft Booster Build Stand

Pin Retainer Steel Strap

Cork Band

Aft Skirt Clevis

Aft Skirt Mate

The aft skirt is placed in the build-up stand and the booster segment is mated. 177 pins are installed and secured with a steel pin retainer strap. The joint is closed out with cork and RT-455 ablative compound.


Aft exit cone is assembled to the forward exit cone at the RPSF.

Aft Skirt Not Shown for Clarity

Forward Exit Cone

Aft Exit Cone

RTV Thermal Barrier

Primary Seal

Secondary Seal

Phenolic

Phenolic

AEC Mate

• Phenolic mating surfaces are primed with DC1200 primer prior to assembly.

• Primary and secondary seals (O-rings) are installed.

• Exit cone is raised on an elevator and floated on an air bearing for mating.

• The joint is bolted with 96 fasteners.

• Leak test is performed at 83 and 30 psig with the mass flow meter prior to joint RTV backfill. The joint gap is backfilled (injected) with RTV silicone sealant as part of thermal barrier system.


If needed, the aft booster will be put into surge for storage. The SRM transporter transfers the aft booster from the RPSF to the surge or the Vehicle Assembly Building (VAB) for the stacking operations.

• Surge buildings protect hardware from elements (rain, wind, etc.)

– Not climate controlled

• Segments have weather proof covers on top

RPSF

VAB

Surge


The segment is connected to the beam and the 325-ton crane in the transfer isle of the VAB. Circularity measurements, tang preps, metal parts inspections, abrade J-leg, and assemble/connect curtain.


The aft booster segment is lifted from the transfer isle to the high bay of the VAB to be connected to the Mobile Launch Platform (MLP). The booster is bolted to the hold down post of the MLP with a frangible nut that separates at launch.


Forward Segment

Forward Center Segment

Aft Center Segment

Aft Booster

Aft Field Joint

Forward Field Joint

Center Field Joint

SRB Forward

Assembly

At KSC, the center and forward segments are stacked. When two segments are mated at KSC, this joint is called a field joint. The SRB forward assembly mated. Then, all field joints are all closed out in the VAB.


• Field joint is a clevis and tang configuration with 177 pins

– Three alignment slots/pins ensure correct segment clocking

• Tang “capture feature” and insulation “j-leg” added during redesign

Tang

Clevis

Field Joint

Example

– Tang capture feature “captures” inner clevis leg to limit seal surface movement (joint rotation) during motor pressurization

– Insulation j-leg prohibits combustion gas from reaching seals

Capture Feature

Inner Clevis Leg

Insulation J-leg

All the field joints are configured with a tang and clevis design with a capture feature. The 3 O-rings and J-leg help prohibit a combustion gas leak at the joints.


For a segment mate, the segment is lowered over the SRB stack. The field joint assembly fixture (FJAF) acts as a “shoehorn” to align the tang/clevis and prevent flat-on-flat metal conditions. Leak test of the joint and the vent port plug are the final acceptance of a successful joint mate.

Field joint mate with 3 feet between the segments.

Field joint mate with 1/8” between the segments.

Segment mates require a controlled environment within the curtain room. Also, the controlled area requires personnel to wear flames, eyes-only hoods, gloves and meet maximum static levels.

O-rings

FJAF

PSA Application


Each field joint is closed out with the field joint protection system (FJPS). The FJPS provides thermal protection, weather protection and retains joint pins.

Cork

Heater Retainer Strap and Thermal

Barrier

Joint Temperature

Sensor

Joint Heater

Pin Retainer Band

RT-455 Ablative

RT-455 Ablative

Cork

Field joint after mate, before FJPS

Field joint with FJPS


The forward assembly is mated to the forward segment and also closed out with FJPS. Since no propellant is exposed in this mate, a controlled environment is not needed.

Forward Skirt JPS

Cork Band

Forward Skirt

Fwd Segment

Pin Retainer Strap

Forward Skirt Joint


The systems tunnel, cables, heater power cables, and linear shaped charge (LSC) are all assembled and closed out. In addition, TPS, cabling and closeouts are completed in other areas of the boosters.

Systems Tunnel Closeout LH side (fwd 3 segments)

Tunnel Cover

Cork

RT-455

Forward and Center Field Joint

Tunnel Closeout

Heater Power Cables


After the boosters are assembled, the external tank (ET) is then brought over from the ET check-out cell in the VAB for the ET/SRB mate.


Next, the orbiter is mated to the ET with the boosters supporting the weight of the whole shuttle.


The crawler transports the MLP and the shuttle to the pad where all processing is completed.


After launch, the boosters separate at around L+128 seconds. The boosters continue to climb to around 42 miles high. Then, boosters tumble until the drogue shoot deploys at 1600 feet, which orientates the boosters upright. The main parachutes deploy at 6300 ft to slow down the boosters to impact the ocean at about 60 mph. Before impacting the ocean, the aft exit nozzle separates to prevent deformation on the reusable motor.


The Liberty Star and Freedom Star each retrieve a booster in the ocean to tow it back to Hanger AF at KSC.


The boosters are received at Hanger AF and evaluated for any off nominal conditions in the post-flight assessment.


Every aspect of the boosters is inspected and compared to past post-flight

data. The segments are disassembled and sent back to ATK and USA.

srb processing

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