The SGT Corporate Fellows and Subject Matter Experts Program identifies technical leaders within SGT. Overall, the threshold for an individual to achieve this recognition is very high, and those selected are the nucleus of SGT’s corporate resume.

Fellows and Subject Matter Experts (SMEs) are a significant resource for all our employees needing their expertise; they provide advanced understanding and architect solutions in support of our customers; they mentor high potential staff, and they give invited talks to the wider SGT community. To date, SGT has selected 50 SMEs and 10 Fellows.

The designation of SGT Fellow is made on a highly limited and competitive basis to recognize exceptionally gifted individuals for their technical achievement in science, engineering, information technology, and/or mission support. Our Fellows have the broad understanding, experience, and expertise required to advance SGT within the marketplace. SGT is proud of the exceptional talent held by our Fellows as is in evidence in their biographical information which follows.

Ben Rodini

A native of Philadelphia, Ben Rodini attended Drexel University earning a B.S.M.E., M.S.M.E. and Ph.D. in applied mechanics there.  He first became interested in composite materials―his area of expertise―in graduate school. He has held professional positions at General Dynamics Fort Worth, General Electric Space Division, Swales and Associates and is now with SGT.   Ben has long been involved with composites on Goddard’s space programs, beginning with LANDSAT 3 and continuing to the James Webb Space Telescope. Currently, he is working with Code 543 as a technical advisor on joining ARES 5 composite rocket components for the Advanced Composites Technology project. An active member of the Baltimore-Washington Chapter of the Society for Advancement of Material and Process Engineering (SAMPE), he also volunteers at the National Air and Space Museum.

Dave Lorenz

Dave Lorenz has worked at NASA/GSFC for most of his 28 years as a professional engineer after graduate work at the University of Maryland.  He has been on both sides of the fence as a contractor and as a Civil Servant.  He began his career as an analyst in what was then the Attitude Analysis Section which later merged with the Orbital Analysis Section to become Flight Dynamics. His first assignment was preparing for the Solar Maximum Mission (SMM) Repair Mission (SMRM), the first on-orbit capture/repair/return-to-orbit of a satellite. It was during this exciting time that Dave was developing a special attitude determination algorithm to generate a crude attitude based on Sun and magnetometer measurements for use following the repair. The mission was a huge success but not without its problems; SMM went into an uncontrolled tumble while being captured by the shuttle crew.  Since then, Dave has worked on a number of interesting missions, primarily as a GN&C engineer. These missions include Landsat-4, -5, and -7, UARS, Terra, Aqua, GOES-8,-9, and -13 and work on ERBS and TRMM. While a Civil Servant, he was the shuttle integration manager for the launch of UARS.   Currently, he is working on GOES-R and Glory performing occasional consulting work for Landsat-5 which has been on orbit since March, 1984.

Ewen Denney, Ph.D.

Ewen Denney has worked at the NASA Ames Research Center since 2002, and has been a senior computer scientist with SGT since 2009. He received his doctorate from the University of Edinburgh, Scotland, in 1999 and is the author of more than 40 publications on formal methods, the holder of two computer science patents, and serves on numerous program committees, as well as the MathWorks Constellation and AeroDef Advisory Boards. He has chaired and co-chaired several conferences, including the inaugural NASA Formal Methods Symposium in 2009, Proof Carrying Code and Software Certification (2009), and Software Certificate Management (2005). He is also a member of the IFIP Working Group on Code Generation and an honorary fellow of the University of Edinburgh.

Julian Vahlberg, Ph.D.

Julian Vahlberg has over 40 years experience in estimation, guidance, and control of aerospace vehicles.  He has used various sensors (inertial, stellar, RF, laser, GPS, etc.) to either estimate the state or performance of a system or better control it. Such applications have included submarines, ships, missiles, aircraft, and satellites. At SGT, as well as on previous contracts, he focused on a satellites and orbit determination. He improved orbit determination procedures so well that normal accuracy was maintained even across major thrusting. When thrust planning failed to achieve adequate station keeping, he delivered software that provided tight control with only a fraction of previous efforts. For failed Attitude Control System (ACS) components, he devised a highly unconventional method to maintain an operational attitude. For failing solar array drive motors, he devised a method for reducing their runtime, thereby extending their remaining life. Julian’s pitch-for- power process allowed significant tasking to resume when power was inadequate due to panel motor failures. When weak batteries threatened a spacecraft, he devised a method of minimizing the stress on the batteries. As a result of these and other activities, the useful, productive lifetime of the satellites was almost doubled. Dr. Vahlberg has a B.S., M.S., and Ph.D. in aeronautical and astronautical engineering from MIT.

Mark Sherman

After earning a B.S.E.E. from the State University of New York at Buffalo, Mark Sherman went to work for Link Simulation Systems, a defense contractor whose primary product was real-time tactical training systems. As a Lead Computer Systems Engineer, Mark designed and implemented custom real-time operating systems, led internal R&D efforts studying the application of new technologies for simulation systems, and created standard processes to simplify the efforts of simulation application developers. Later, Mark moved to the support services industry by joining Systems and Applied Sciences Corporation, which eventually became part of Raytheon. He joined SGT in 2005, where his contract efforts have been primarily directed to systems architectures, science data processing, data archiving, inter-process communications systems, and user interface development. His broad expertise in information technology and systems development have made Mark a valuable contributor to new business development at SGT and his efforts have helped the company to win a number of contracts.

Michael Woronowicz, Ph.D.

Michael Woronowicz is the head of SGT’s Modeling and Contamination Analysis Section, Contamination Engineering and Thermal Coatings Group, which is generally associated with the MSES II program at NASA Goddard Space Flight Center.  In performing a great variety of mass transport analyses associated with spacecraft and associated instruments, from design through testing phases, as well as troubleshooting issues on orbit, he has supported over 40 tasks governed by various NASA Centers and the Johns Hopkins University Applied Physics Laboratory. Michael received his B.S. in mechanical engineering from Cornell University, followed by a master’s and a Ph.D. degree in aeronautics and astronautics from Stanford University.  When he was an engineering co-op student working for Hughes Aircraft he was awarded a Master’s Fellowship. Upon final graduation, Michael worked as a researcher for a contractor at NASA Langley Research Center.  It was there he became aware of contamination control work being performed at Goddard. He assumed his current position in 1994. He is a recipient of NASA’s Exceptional Achievement Award. 

Mihaela Fulop

Mihaela Fulop is the Senior Metrology Engineer currently working at the NASA Glenn Research Center.  Born and reared in Calarasi, Romania she earned her bachelor’s degree in physics, with an emphasis in metrology, at the University of Bucharest. While at the university she also completed an internship at the National Institute of Metrology. Marrying her college sweetheart, Mihaela moved to United States and became a citizen. After working as an associate engineer at Meriam Instruments for six years, she was hired as a pressure engineer at the NASA Glenn Calibration Lab in 2003.  She received several awards at Glenn and in 2008, she was the recipient of SGT’s esteemed President’s Award.  She has collaborated with the most prestigious metrologists in the country, developing reference publications and  national standards related to measurement uncertainities, measurement decision risk as well as other analytical metrology subjects. One of her noteworthy projects was an analytical comparison of a NASA-developed handbook to one developed by the NSCLI, a complicated task because both documents use advanced mathematics and each uses different techniques to solve the same problems.  Recently, she developed two NASA training classes―Estimation and Evaluation of Measurement Decision Risk and Measurement Uncertainty Analysis Principals and Methods.

John McCarthy, Ph.D.

An SGT employee since February 2005, John McCarthy has over 20 years experience in supervision of technical personnel, geodetic data analysis, orbital error analysis, space physics, geodesy, and computer programming. He has directed orbital error analysis studies for future satellite missions and geophysical research using satellite altimeter data. In addition, John has extensive experience in developing and implementing computer algorithms for satellite data processing and orbit error analysis using a variety of computers and languages. He is currently working on the processing of GRACE gravity data to measure the mass loss in glaciers in Alaska, and in the ice sheets of Greenland and Antarctica and is also developing simulation software for evaluating altimeter methods of measuring ice sheet mass loss via future satellites. Prior to SGT, he was with the GGSG group. John received his bachelor of science degree from the California Institute of Technology and a doctorate in physics from the University of Maryland. In addition to his responsibilities with SGT, he has given several courses on geodetic data analysis and software in Europe, Canada and the U.S.

Stuart Frye

A systems engineer working at the NASA Goddard Space Flight Center (GSFC), Stuart Frye is  Principal Investigator on sensor Web technologies that link Earth Observation satellites, aerial and in situ systems, forecast and nowcast models, and regional/local socioeconomic data into an interoperable set of disaster management components and services.   He is the point-of-contact for the Group on Earth Observations task DI-09-02B and serves as project manager for Regional End-to-End Disaster Pilots coordinating the Committee on Earth Observation Satellites Strategic Implementation Team Disaster Management working group and the NASA Earth Science Technology Office Sensor Web activities.  Stuart also serves as the technology liaison with the SERVIR project, UN-SPIDER, World Bank, International Red Cross, and other aid and relief organizations to infuse standard Web services that provide open access to critical disaster management information and maps via the Internet, using common desktop tools.  He also leads a hyperspectral remote sensing research testbed at GSFC for developing sensor Webs and autonomous systems for use on such decadal survey missions as HyspIRI..  He was co-winner of the R&D 100 Award in 2008 for the Sensor Web 2.0 technology development and won the 2005 NASA Software of the Year award for his role in the autonomous science craft experiment on-board the EO-1 satellite.  Stuart has a bachelor’s degree in mathematics from the University of California and a master’s degree in operations research from the George Washington University.

David Hall

As the Group Manager of the Collaborative and Assistant Systems, Discovery and Systems Health Group since 2002, David Hall provides strong leadership within the Intelligent Systems Division at NASA Ames Research Center (LaRC).  He is an outstanding computer scientist, researcher and development leader, and mentor for junior engineers and scientists.  Moreover, he is known for his ability to assume team leadership, instilling software process and discipline, and producing exceptional products.  David was instrumental in LaRC’s success in supporting the Columbia Accident Investigation Team. He has been a principle architect of the ADAPT prognostic and diagnostic testbed, and made significant contributions to Livingstone flight diagnostic system (flown on EO-1). He has provided oversight of the development staff for the Brahms multi-agent architecture system since he has been with LaRC.  David has been the recipient of many awards including NASA Group Achievement Awards, a Space Act Award, theTurning Goals Into Reality Award, and a “Best Paper” Award.  He was formerly the vice president of technology at Zip2/MyWay.com providing  technical leadership and improvements in capability, scalability and efficiency to existing engineering and QA teams. As the VP of technology at eProNet, David was a member of the executive team and led software engineering and product management.  He has a master’s degree in computer science from Rutgers University and completed all the elements of a Ph.D. absent a thesis.  He received his undergraduate degree from the College of William and Mary.

Dr. Johann Schumann

Dr. Johann Schumann is currently the Chief Scientist of Computational Sciences under the ISRDS/Robust Software Engineering contract at NASA Ames Research Center.  Dr. Schumann received his Habilitation Degree (Dr. rer. Nat. habil.) for Computer Science in 2000 and his Doctoral Degree (Dr. rer. Nat.) Computer Science in 1991 from the Technische Universitat Munchen, Germany.  Within the past 10 years Dr. Schumann has patented several tools including: The Autofilter Program Synthesis System NASA Invention Disclosure (N1679) (2009); Bayesian V&V tools for adaptive Systems (Envelope tool and Parameter Confidence Tool) NASA Invention Disclosure (N1679) (2005); and the Confidence Tool and Monitoring Harness for Neural-Networks Based Control NASA Invention Disclosure (N1679) (2003); as well as published several books and papers including: Applications of Neural Networks in High Assurance Systems (Studies in Computational Intelligence) (2010); Software V&V Support by Parametric Analysis of Large Software Simulation Systems (2009); Tool Support for Parametric Analysis of Large Software Simulation Systems (2008); Statistical Evaluation Methods for V&V of Neuro-Adaptive Systems (2008); Parametric Analysis of ANTARES Re-entry Guidance Algorithms Using Advanced Test Generation and Data (2008).  Dr. Schumann received the RIACS Service Award in 2006 and the NASA Software Release Award and the RIACS Performance Award for Technical Leadership Award in 2004.  Prior to joining SGT, Inc., Dr. Schumann worked for RIACS/USRA as the PI of NASA OSMA/SARP Grant “Advanced Tools and Techniques for the V&V of IVHM systems” (2009-2010); USRA PI of NRA Grant “ISHM: Tools and Techniques for Software and System Health Management;” and was a part time Senior Lecturer (Level B) in the Department of Computer Sciences at San Jose State University.

Rohit Mital

Rohit Mital came to SGT in 2010 as part of SGT's acquisition of Master Solutions (MSL). Rohit has expertise and experience in technology strategy, system architecture, software design and implementation in a variety of industries including insurance and financial services, telecom, government and DoD. His background includes delivering high-performance SOA-based integration software, employing open-source solutions and developing web 2.0 and social-network applications. His focus areas include Cloud computing, SOA, enterprise data integration, metadata management, and software development.

Prior to joining SGT, Rohit was a founder and Chief Technology Officer(CTO) for a venture-backed software company that developed and marketed SOA-based enterprise integration software suite. As CTO, he was responsible for overall software strategy and technical direction of the company. Rohit has provided mentoring and technical leadership to local technology start-up companies in Colorado Springs. He has been using his broad expertise in information technology and his experience with SOA to contribute to business development at SGT. Rohit also provides IT architecture and design support to SGT clients as a solution architect.

Rohit has a a Bachelor's and Master's degree in Electrical Engineering and a Master's degree in Mathematics. In 2005, Fast Company Magazine featured Rohit as one of the creative people in emerging cities across United States.