Stephen Whitmore

Mechanical and Aerospace Engineering

Faculty

Professor

Contact Information

Go toOffice Location: ENGR 419F
DialPhone: 435-797-2951
SendEmail: stephen.whitmore@usu.edu

Educational Background

PhD, Aerospace Engineering - Flight Dynamics and Control, (Applied Mathematics, Fluid Mechanics), University of California, Los Angeles, 1989 Dissertation

Formulation and Verification of a Technique For Compensation of Pneumati Attenuation Errors in Airborne Pressure Sensing Devices

Other, University of California, Los Angeles, 1987

MS, Mechanics and Structures, University of California, Los Angeles, 1983 Thesis

Formulation and Implementation of a Practical Algorithm for Non-Stationary Adaptive State Estimation with Applications to Air Mass Reference Measurements

BS, Aerospace Engineering, University of Illinois, Urbaba-Champaign, 1980

Expertise

Dr. Whitmore's recent research focus at USU is on the development of piloted simulation models for lunar-return lifting reentry vehicles, with an emphasis of developing high-precision low-dispersion footprint techniques for lifting aero-capture and aero assist. He is supporting the NASA and Lockheed CEV Entry, Descent, and Landing EDL team.

Biography

Dr. Stephen Whitmore Whitmore is currently Associate Professor of Mechanical and Aerospace Engineering. He has more than 30 years of technical, management, and academic experience in the aerospace industry. He has received multiple national awards including the NASA Engineering Achievement Medal and Utah Engineering Educator of the Year.

Teaching Interests

Dr. Whitmore teacjes upper division and graduate classes in fluid mechanics (MAE 5420 Compressible Fluids), propulsion systems (MAE 5540 Propulsion Systems, and MAE 6530, Advanced Propulsion Concepts), and instructs a section of the capstone senior design course (MAE 4800, 4810. His senior design teams have won the NASA-sponsored University Student Launch Initiative (USLI) Competition at Huntsville, AL, four times (2008, 2009, 2011, and 2012). Previously Dr. Whitmore instructed the junior level Instrumentation and measurements class (MAE 3340). Prior to his USU service Dr Whitmore instructed courses in Space Systems (SS3011), and Astrodynamics (AE 4362), at the Naval Postgraduate School in Monterey, CA.

Research Interests

Dr. Whitmore is an associate fellow of the American Institute of Aeronautics and Astronautics (AIAA) and is currently an active member of both the AIAA Space Systems and Hybrid Rockets Technical Committees. Dr. Whitmore serves as the faculty advisor for the USU AIAA student chapter. He has published more than 120 technical monographs including peer reviewed journal papers, peer reviewed NASA technical papers and memoranda, papers in conference proceedings, and book chapters. Dr. Whitmore is a strong advocate for the developing commercial space industry, and since coming to USU has procured more than $1.7 million in research funding. His funding sources have included NASA, DoD, Federally Funded Research and Development Centers (FFRDC), the Utah Governor’s Economic Development Council, and private Industry. He is currently teaming with multiple small startup companies to develop technologies that directly support NASA’s Commercial Crew Development (CCD) initiative. Dr. Whitmore is director of the Propulsion and Rocketry program at USU. His current research focus is directed towards developing less hazardous, environmentally-friendly "green" propellant replacements for hydrazine. His research team has recently developed a novel micro-hybrid gas generator that uses inexpensive and environmentally friendly nitrous oxide and acrylonitrile-butadiene-styrene (ABS) as propellants. This device operates by "hydrocarbon seeding" an oxidizing flow with inert solid propellant vaporized by a high-voltage, low wattage electrical spark. The technique is fundamentally different from all other current or proposed “green propellant” solutions. The ignitor concept offers the simplicity of a monopropellant feed, and has been demonstrated effectively with either gaseous oxygen or nitrous oxide as the potential working fluids. Combustion gas byproducts from the hydrocarbon-seeding process are non-toxic and non-corrosive, and exceed 2500 C. Currently, this novel micro-hybrid gas generator technology is being evaluated as a means thermally dissociate aqueous solutions of varying mass-concentrations of hydroxylamine nitrate (HAN). This ammonium salt lies within a class of ionic liquids (ILs) that have recently been investigated as alternative "green" spacecraft propellant replacements for hydrazine. With the current state of the art, propellants based on aqueous IL-solutions are notoriously difficult to ignite, and a “cold-start” capability does not exist. Existing catalyst beds used to dissociate the IL component of the solution must be pre-heated to greater than 350 C before firing. This shortcoming is especially disadvantageous for small satellite propulsion systems where energy conservation and volumetric efficiency are primary considerations. When fully developed the proposed IL-ignition technology eliminates the need for a pre-heated catalyst bed, a high wattage power source, toxic pyrophoric or hypergolic ignition fluids, or bi-propellant spark ignitors; as are currently required for igniting IL-based propellants. His research team has recently completed work on the development of a novel regeneratively-cooled aerospike thruster -- the Multiple Use Plug Hybrid (for) Nanosats (MUPHyN). The MUPHYN system provides attitude and velocity control using secondary-injection thrust vectoring without mechanical nozzle gimbals or additional reaction control thrusters. A major outcome of the research activities was that the side force amplification due to secondary injection was clearly demonstrated. Here Injection points near the end of the truncated spike produced the highest force amplification factors. For secondary injection near the end of the aerospike, side force amplification factors up to 1.4. This amplification has never been demonstrated for a cold-gas injection system. The enhanced side force specific impulse means that the same control impulse can be achieved for significantly less propellant than would be used by a stand-alone reaction control thruster. Thrust vectoring ports on an aerospike nozzle allow for small impulse attitude control maneuvers without primary flow active, and the aerospike nozzle with secondary injection also provides the possibility to replace conventional reaction control thrusters. Both larger impulse ΔV and small impulse attitude control and proximity operations burns can be performed with the same system. This synthesis of technologies is unique to the MYPHyN thruster design and no other commercial or government entity has produced comparable work that has been published in open literature. The resulting system is compact, non-toxic, non-explosive, and uses non-pyrotechnic means for reliable motor ignition. When fully developed, this enhanced propulsive capability will enable multiple CubeSats to be deployed simultaneously by a single launch vehicle and independently repositioned, a key enabling technology for multi-point measurement science missions. His recent paper entitled, "Development and Testing of a Multiple Use Plug Hybrid (for) Nanosats (MUPHyN),” was recently selected as Best Overall Paper for the Hybrid and Solid Propellant Technical Sessions at the 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, Atlanta, Georgia, 30 July - 01 August 2012. Before developing the MUPHyN thruster, Dr. Whitmore's team was funded on a proposal entitled, “Direct-Digital Manufacture of Hybrid Rocket Fuels and Motors.” by the Utah Governor's Economic Development Office’s Center of Excellence (COE) program. A second major outcome of this research is that the acceptability of ABS as a hybrid rocket fuel grain material has been clearly demonstrated. This analysis suggests that preparations of ABS may be better optimized for hybrid propellant performance; but also the mixture that produces best results is closely coupled with the operating O/F ratio of the motor. In all cases the viability of industrially produced ABS fuel grains has been clearly proven. Future studies will emphasize methods for increasing the burn efficiency of the ABS fuel material formulation. This result is significant because of the recent rapid capability growth in factory automation and robotics. Direct-Digital Manufacturing (DDM) offers the potential to revolutionize methods used to fabricate hybrid rocket fuel grains. DDM technology can support high production rates with a much greater degree of motor-to-motor consistency than is possible using traditional “one-off” motor casting methods. If matured and commercialized, this technology will have a transformational effect on hybrid rocket motor production by improving quality, consistency, and performance, while reducing development and production costs.

Awards

NASA MSFC Summer Facuty Fellow Appointment, 2016

NASA Marshall SpaceFlight Center

NASA MSFC Summer Facuty Fellow Appointment, 2015

NASA Marshall SpaceFlight Center

Best Technical Paper, 2012

Hybrid and Solid Propellant Technical Sessions

Winning Team, Faculty Mentor to Student Design Team NASA/ATK University Student Launch Initiative 2012, 2012

NASA Marshall Spaceflight Center

Winning Team, Faculty Mentor to Student Design Team NASA/ATK University Student Launch Initiative 2011 , 2011

NASA Marshall Spaceflight Center

Best Technical Paper, 2010

Ground Test Sessions, 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference

Utah Engineering Educator of the Year , 2009

Utah Engineering Council, Governor's Economic Council

Winning Team, Faculty Mentor to Student Design Team , 2009

NASA/ATK University Student Launch Initiative

Utah Aerospace Engineering Educator of the Year , 2008

Utah Section, AIAA

Winning Team, Faculty Mentor to Student Design Team, 2008

NASA/ATK University Student Launch Initiative

Finalist Astronaut Class, 2002

Associate Fellow Appointment , 2000

American Institute of Aeronautics and Astronautics

NASA Headquarters Achievement Award - Engineering Achievement Medal , 1997

NASA

NASA DFRC Honor Award - Outstanding Paper for Year 1996, 1996

NASA

NASA DFRC Honor Award - Outstanding Scientist for Year 1993, 1994

NASA

Excellence in Technical Presentation Award, Aerotech '91, 1991

Society of Automotive Engineers (SAE)

NASA ARC Honor Award - Outstanding Scientist for Year 1989, 1990

NASA

NASA Headquarters Honor Award - Group Engineering Achievement Award , 1984

NASA Headquarters