Draper's MBE Approach
Beyond meeting the exacting performance standards of the MARK 6 missile guidance system, Draper’s work as prime contractor on the Trident II MARK 6 MOD 1 required staying within budget, delivering on schedule and accounting for total lifecycle costs over decades — all while working with a technical team distributed across multiple organizations. To effectively manage the complex process, Draper chose a modular, model-based engineering (MBE) approach. MBE enabled Draper to progress from concept to design, integration, validation and life-cycle support successfully and more rapidly than in the past.
Combining a Guidance System Design Process in an MBE Unified Virtual Environment
Implementing the entire guidance system design process in an MBE unified virtual environment provided a sophisticated understanding of overall system and subsystem interactions as they were in development. Using modeling and simulation for trade-space analysis allowed rapid quantitative comparison of competing system and component concepts. Draper was able to evaluate and refine new technologies simultaneously, make adjustments and see their impact across the entire system.
For example, Draper did extensive trade-space analysis to evaluate two solid-state gyroscope design options against the deployed mechanical gyro. Using MBE, Draper evaluated the design candidates for technical and cost viability within the guidance system design, against system performance specifications, without having to build prototypes. MBE and modular design enabled the final gyro selection to be deferred while the technology matured, without affecting the overall system design schedule. This MBE assessment approach meant that hardware did not have to be incorporated until later in the process — reducing the amount of breadboard hardware made by more than 75 percent compared to the MK 6. The resulting interferometric fiber-optic gyroscope technology was selected for both the missile guidance and submarine navigation systems.
Development of Enhanced Ground Testing (EGT)
Draper augmented and validated its MBE process by developing a new set of nondestructive test methods called Enhanced Ground Testing (EGT), which gave the Navy the confidence to skip the land-based launch pad tests that historically had been done before launching test flights from manned submarines. Omitting these pad tests avoided approximately $150 million in flight test costs.
Draper's Achievements
Currently deployed in the submarine fleet, the MK 6 MOD 1 will be easier to maintain and refresh in part due to the reservoir of data captured and saved during its design and testing. This library of high-fidelity models and data — ranging from validation of requirements and testing of component designs to field test data and production — will be valuable in designing the next generation of ballistic missile guidance systems.
For its work on the MK 6 MOD 1, in 2012 the U.S. Navy Strategic Systems Programs and Draper received the Department of Defense Systems Engineering Top 5 Programs Award.
Because MBE provided early insight into its accuracy and reliability, integration of the new missile navigation system design took only nine months, compared to more than two years for the previous MK 6 system. Software problems were identified and fixed in a matter of weeks, as opposed to months. Draper was able to reduce expensive prototypes by 50 percent compared to the MK 6 design. New ASIC designs were verified and validated seven of seven times attempted — a 100 percent rate of success of first-pass integration.