Solid Rocket Booster Processing Kennedy Space Center

Solid Rocket Booster Processing

• Kennedy Space Center

• SRB Mechanical Engineering

• NE-M7

KSC – Solid Rocket Booster (SRB) Processing Areas

KSC – Solid Rocket Booster (SRB) Processing Areas

KSC – Solid Rocket Booster (SRB) Processing Flow

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

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

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.

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

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.

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.

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.

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.

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.

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

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.

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.

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.