Johns Hopkins APL Marks 15 Impactful Years of Pushing the Boundaries of Missile Design

Missile design is a complex game of trade-offs. It’s not simply a matter of designing a single system, but of coordinating the interplay of a host of subsystems, each one optimized to meet a different objective.

Traditional design processes are simply not up to the task — they are too linear, too sequential, to effectively manage conflicting objectives. So, any design deficiencies arising from a mismatch between subsystems show up too late in the process, resulting in costly delays or even canceled projects.

For 15 years, the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, has been advancing a new paradigm, known as multidisciplinary design optimization (MDO), that overcomes the limitations of traditional processes. Along the way, APL has developed cutting-edge MDO tools — for designing missile systems and related technologies — that have supported a wide range of government agencies and advanced the state of the art among industry partners and government sponsors.

“You don’t achieve optimal system-level performance by putting together a collection of optimal subsystems — in fact, that approach often produces suboptimal results because it’s not clear which discipline should drive any particular design decision,” said Jonah Gottlieb, a systems engineer who leads multiple MDO efforts in APL’s Air and Missile Defense Sector (AMDS). “MDO integrates relevant disciplines so that subsystems are designed through the lens of whatever matters most at the highest level.”

Fidelity at the Speed of Relevance

APL’s flagship tool suite for MDO is known as Optimization of Rockets for Intercept Operations (ORION). The idea for ORION originated circa 2008, when the Missile Defense Agency (MDA) called on APL to help design the Standard Missile-3 (SM-3) Block IIA missile. It was not used for that program, but APL personnel recognized the need for a capability like ORION.

“MDA did not ask APL to build the tool,” Gottlieb explained. “It asked us to answer certain questions about the design of the missile, and we realized that we needed to build a tool in order to answer those questions.”

What the APL team realized was that the success of the SM-3 Block IIA — and for that matter, any modern system involving rockets, for any purpose — hinged on performing integrated multidisciplinary physics-based modeling of the key drivers of design and performance as early as possible. The Laboratory’s deep expertise in systems engineering and physics-based modeling and simulation, combined with the breadth and depth of its knowledge of missiles and their subsystems, put it in a unique position to rise to the challenge of performing rapid conceptual design turns on entire missile systems.

The problem was put to Dan Clemens, an aerospace engineer in AMDS, who happened to share an office with Jerry Emhoff, a fellow aerospace engineer in APL’s Space Exploration Sector (SES) who shared Clemens’ interest in MDO and physics-based modeling and simulation. Clemens developed an initial prototype for performing basic analyses, then handed it off to Emhoff, a self-taught programmer, who improved the speed of Clemens’ prototype code by a factor of 60. The two have formed the core of the ORION development team ever since.

ORION was first used to support the design of the SM-3 Block IIB missile in 2010. This effort was described in a 2014 article in the Johns Hopkins APL Technical Digest that included Gottlieb and Clemens among its authors. Since then, ORION has been used by teams in APL’s AMDS, SES and Force Projection Sector to support a wide range of sponsors in the Department of Defense — including MDA, the Navy, Army, Air Force, Strategic Capabilities Office, Defense Advanced Research Projects Agency and Space Security and Defense Program. It has been applied to ballistic missile defense, anti-air warfare and space launch vehicles. In 2016, an APL team won an award for the Multi-Object Kill Vehicle Program in support of MDA; ORION was integral to that effort.

The key to ORION’s efficacy is captured in a tagline used to describe its core purpose: “fidelity at the speed of relevance.”

“Think of having a slider knob similar to volume control on a stereo, but for the level of fidelity in a physics model,” Gottlieb said. “With ORION, we’re able to adjust the level of fidelity as needed to quickly narrow in on the most relevant combination of trade-offs for any given design before moving forward.”

Broad Expertise

The ORION team at APL spans multiple Laboratory sectors and comprises diverse areas of expertise, including trajectory optimization, thermal analysis, advanced solid rocket motor propulsion and airframe structural survivability. Contributors to recent capability enhancements include John Mark Mines, Andrew Patterson, Jason Leggett, Gus Terlaje, Josh Higginson and Paige Nardozzo, among many others.

The team published and presented at the American Institute of Aeronautics and Astronautics (AIAA) SciTech conference in January.