Original Versus Redesigned Field Joint
The SRM field-joint metal parts, internal case insulation and seals were redesigned and a weather protection system was added.

Original Versus Redesigned SRM Case-to-Nozzle Joint
The SRM case-to nozzle joint has been redesigned to satisfy the same requirements imposed upon the case field joint.

Nozzle
The internal joints of the nozzle metal parts have been redesigned.

Factory Joint
Minor modifications were made in the case factory joints.

Propellant
The motor propellant forward transition region was recontoured.

Ignition System
Several minor modifications were incorporated into the ignition system.

Ground Support Equipment
The ground support equipment has been redesigned.

Design Analysis Summary
Continuing these analyses will ensure that the design integrity and system compatibility adhere to design requirements and operational use.

Verification/Certification Test
The verification program encompasses the following program phases: development, certification, acceptance, preflight checkout, flight and postflight.

Non-destructive Evaluation
The Shuttle 51-L and Titan 34D-9 vehicle failures, both of which occurred in 1986, resulted in major reassessments of each vehicle's design, processing, inspection and operations.

Contingency Planning
To provide additional program confidence, both near- and long-term contingency planning was implemented.

Independent Oversight
At the request of the NASA administrator, the National Research Council established an Independent Oversight Panel.