2024

S. Kumar, D. Thomas, & J. Cassibry, “Nuclear Thermal Propulsion: Trades and Sensitivity Analysis for Robotic Missions,” AIAA SciTech, January 8-12, 2024. (accepted)

H. Johnson, H. Kannan, & D. Thomas, “Demonstrating the Practicality of a Space Systems Ontology through Example Systems,” AIAA SciTech, January 8-12, 2024. (accepted)

M. Halvorson, N. Moyers, C. Domani, H. Johnson, H. Kannan, P. Sriman, P. Lewis, & D. Thomas, “The Unified Ontological Foundry: A Multi-Organization Solution to the Urgent Problem of Ad-Hoc Domain Ontologies,” AIAA SciTech, January 8-12, 2024. (accepted)

H. Kannan, P. Sriman, & D. Thomas, “A Theory-Driven Domain Ontology for Problem Space Representation in Systems Engineering,” AIAA SciTech, January 8-12, 2024. (accepted)

S. Raghu, S. Rawlins, & D. Thomas, “Demonstration of a Reliability-Driven Framework for Rocket Engine Development, Test, and Verification,” AIAA SciTech, January 8-12, 2024. (accepted)

M. Schroll, R. Frederick, & D. Thomas, “Preliminary Study of Alternative Propellant Performance with CNTP,” AIAA SciTech, January 8-12, 2024. (accepted)

Di. Nikitaeva & D. Thomas, “Lunar In-Situ Resource Utilization of Aluminum Metal for Radiator Face Sheet Production of Pylon Fission Surface Power System,” AIAA ASCEND, 23–25 October 2023. (accepted)

C. White, C. Eaton, T. Yeazitzis, K. Weger, B. Mesmer, D. Thomas, “Survey Responses on Improvement Mechanisms of Affordability at NASA MSFC,” American Society for Engineering Management 2023 International Annual Conference and 44th Annual Meeting, October 25–28, 2023. (accepted)

D. Thomas, “Nuclear Thermal Propulsion – Progress and Potential,” International Astronautical Congress, Baku, Azerbaijan, October 2-6, 2023.

S. Raghu, J. Buettner, & D. Thomas, “Application of Model-Based Systems Engineering (MBSE) to Rocket Engine Affordability and Potentials,” International Astronautical Congress, Baku, Azerbaijan, October 2-6, 2023.

D. Thomas, M. Houts, D. Wang, K. Hollingsworth, R. Frederick, & J. Cassibry, “Research Progress toward Engineering Feasibility of the Centrifugal Nuclear Thermal Rocket,” International Astronautical Congress, Baku, Azerbaijan, October 2-6, 2023.

S. Kumar, D. Thomas, & J. Cassibry, “Application of Nuclear Thermal Propulsion for Sustainable Cislunar Exploration,“ International Astronautical Congress, Baku, Azerbaijan, October 2-6, 2023.

S. Rawlins & D. Thomas, “Application of the Reliability-Driven Design and Test Methodology to Nuclear Thermal Propulsion Systems,” International Astronautical Congress, Baku, Azerbaijan, October 2-6, 2023.

M. Schroll, R. Frederick, & D. Thomas, “System Design Optimization for a Centrifugal Nuclear Thermal Rocket,” International Astronautical Congress, Baku, Azerbaijan, October 2-6, 2023.

W. Ziehm & D. Thomas, “A Trade Study of Mission Architectures for Centrifugal Nuclear Thermal Propulsion,” International Astronautical Congress, Baku, Azerbaijan, October 2-6, 2023.

S. Rawlins & D. Thomas, “Overview of the Reliability Driven Design and Test Methodology Applied to Nuclear Thermal Propulsion Systems,” Nuclear and Emerging Technologies for Space (NETS) 2023, Idaho Falls, Idaho, May 7-11, 2023.

W. Ziehm & D. Thomas, “Exploring the Feasibility of Kuiper Belt Missions Supported by Centrifugal Nuclear Thermal Propulsion,” Nuclear and Emerging Technologies for Space (NETS) 2023, Idaho Falls, Idaho, May 7-11, 2023.

S. Kumar, D. Thomas, & J. Cassibry, “Preliminary Nuclear Thermal Propulsion Engine System Trades for Robotic Missions to Jupiter,” Nuclear and Emerging Technologies for Space (NETS) 2023, Idaho Falls, Idaho, May 7-11, 2023.

Di. Nikitaeva & D. Thomas, “Radiator Production for Pylon Fission Surface Power System on the Moon,” Nuclear and Emerging Technologies for Space (NETS) 2023, Idaho Falls, Idaho, May 7-11, 2023.

T. Blackman, M. Schroll, R. Frederick, & D. Thomas, “Continuing Experimental Efforts for Simulating a Centrifugal Nuclear Thermal Rocket Engine,” Nuclear and Emerging Technologies for Space (NETS) 2023, Idaho Falls, Idaho, May 7-11, 2023.

M. Schroll, R. Frederick, & D. Thomas, “Reactor Core Geometry Optimization with Application for Centrifugal Nuclear Thermal Rockets,” Nuclear and Emerging Technologies for Space (NETS) 2023, Idaho Falls, Idaho, May 7-11, 2023.

H. Johnson, D. Thomas, & M. Diaz, “Developing and Testing a Common Space Systems Ontology using the Ontological Modeling Language,” IEEE Aerospace Conference, Big Sky, Montana, March 4-11, 2023.

J. Buettner, S. Raghu, & D. Thomas, “A System Engineering Approach to Assess the Benefits of Additive Manufacturing for Rocket Engines,” IEEE Aerospace Conference, Big Sky, Montana, March 4-11, 2023.

M. Houts, D. Thomas, & B. Nassersharif, “Centrifugal Nuclear Thermal Rocket Challenges and Potential,” American

Astronomical Society Rocky Mountain GN&C Conference, Breckenridge, Colorado, February 3-8, 2023.

W. Ziehm & D. Thomas, “Mission Design Analysis with Centrifugal Nuclear Thermal Propulsion,” AIAA SciTech, National Harbor, Maryland, January 23-27, 2023.

J. Buettner, S. Raghu, & D. Thomas, “Understanding the Benefits of Utilizing Additive Manufacturing (AM) for Liquid Rocket Engine Components and its Quantification Using Model-Based Systems Engineering (MBSE),” AIAA SciTech, National Harbor, Maryland, January 23-27, 2023.

S. Rawlins & D. Thomas, “Nuclear Thermal Propulsion System-level Uncertainty Reduction Through Reliability-Driven Design,” 13th Liquid Propulsion and 12th Spacecraft Propulsion Joint Army Navy NASA Air Force (JANNAF) Joint Subcommittee Meeting, Huntsville, Alabama, December 5-9, 2022.

M. Schroll, D. Santana, R. Frederick, & D. Thomas, “Experimental Study of Liquid Core Bubble Dynamics in a Centrifugal Nuclear Thermal Rocket Engine”, 13th Liquid Propulsion and 12th Spacecraft Propulsion Joint Army Navy NASA Air Force (JANNAF) Joint Subcommittee Meeting, Huntsville, Alabama, December 5-9, 2022.

W. Ziehm & D. Thomas, “Centrifugal Nuclear Thermal Propulsion for Scientific Missions to Jupiter,” 13th Liquid Propulsion and 12th Spacecraft Propulsion Joint Army Navy NASA Air Force (JANNAF) Joint Subcommittee Meeting, Huntsville, Alabama, December 5-9, 2022.

M. Schroll, R. Frederick, & D. Thomas, “Baseline Analysis for Centrifugal Nuclear Thermal Rocket Engine Configuration,” Nuclear and Emerging Technologies for Space (NETS) 2022, Cleveland, Ohio, May 8-12, 2022.

S. Kumar, D. Thomas, & J. Cassibry, “Development of Integrated NTP Mission Model for Planetary Science Missions,” Nuclear and Emerging Technologies for Space (NETS) 2022, Cleveland, Ohio, May 8-12, 2022.

D. Nikitaeva & D. Thomas, “Power Generation on the Moon for Future In-Situ Resource Utilization,” Nuclear and Emerging Technologies for Space (NETS) 2022, Cleveland, Ohio, May 8-12, 2022.

S. Rawlins & D. Thomas, “Derivation of NERVA's 'KEEP IT SIMPLE' System-Level Reliability Model,” Nuclear and Emerging Technologies for Space (NETS) 2022, Cleveland, Ohio, May 8-12, 2022.

B. Campbell, R. Frederick, & D. Thomas, “Initial Experiment Designs Studying Gas Bubble Flows in Liquids for use in Centrifugal Nuclear Thermal Propulsion,” Nuclear and Emerging Technologies for Space (NETS) 2022, Cleveland, Ohio, May 8-12, 2022.

A. Aueron & D. Thomas, “Preliminary Feasibility Study of Electric Pump Fed Nuclear Thermal Propulsion,” Nuclear and Emerging Technologies for Space (NETS) 2022, Cleveland, Ohio, May 8-12, 2022.

M. Halvorson, J. Fuchs, P. Kung, & D. Thomas, “A Model-Based Systems Engineering Approach to Space Mission Education of a Multidisciplinary, Geographically Disperse Student Workforce,” 4th Symposium on Space Educational Activities, Barcelona, April 27-29, 2022.

M. Halvorson & D. Thomas, “Architectural Framework Standardization for Satellite Flight Software Generation Using MBSE and F'”, IEEE Aerospace Systems Conference, Big Sky, Montana, March 5-12, 2022.

J. Keese, K. Hollingsworth, & D. Thomas, “Modeling and Experimental Investigation of Bubbly Flows in Liquid Metal for CNTP,” IEEE Aerospace Systems Conference, Big Sky, Montana, March 5-12, 2022.

S. Kumar, D. Thomas, & J. Cassibry, “A Model-Based Framework for Robotic Missions Using Nuclear Thermal Propulsion Systems,” IEEE Aerospace Systems Conference, Big Sky, Montana, March 5-12, 2022.

A. Aueron & D. Thomas, “An Assessment of Electric Pump Fed Nuclear Thermal Propulsion,” AIAA SciTech, January 3-7, 2022.

J. Keese, K. Hollingsworth, & D. Thomas, “Past Experimental Investigations of Bubbly Flow Applied to Centrifugal Nuclear Thermal Propulsion,” AIAA SciTech, January 3-7, 2022.

A. Aueron & D. Thomas, "Evaluating Tension between Specialization and Generalization in System Design with Excess Functionality," AIAA SciTech, Nashville, Tennessee, January 11-15, 2021. https://doi.org/10.2514/6.2021-1040

S. Godshall & D. Thomas, "U.S. Space Force Collaborative Education System: Needs Analysis and Concept Exploration," AIAA SciTech, Nashville, Tennessee, January 11-15, 2021. https://doi.org/10.2514/6.2021-1436

V. Lopez, A. Flint, & D. Thomas, "Programmatic Management for the AEGIS CubeSat in a Model Based System Engineering Environment," AIAA SciTech, Nashville, Tennessee, January 11-15, 2021. https://doi.org/10.2514/6.2021-0623

D. Nikitaev & D. Thomas, "Transient Performance of a Nuclear Thermal Propulsion Engine Utilizing Seeded Hydrogen," AIAA SciTech, Nashville, Tennessee, January 11-15, 2021. https://doi.org/10.2514/6.2021-0045

D. Nikitaeva, D. Thomas, A. Aueron, S. Kumar, & D. Nikitaev, "Nuclear Thermal Propulsion Spacecraft Integrated System Model," AIAA SciTech, Nashville, Tennessee, January 11-15, 2021. https://doi.org/10.2514/6.2021-1922

S. Raghu & D. Thomas, "Model Based Failure Mode, Effects and Criticality Analysis (MBFMECA) for the RS-25 Engine using SysML," AIAA SciTech, Nashville, Tennessee, January 11-15, 2021. https://doi.org/10.2514/6.2021-0305

I. Rountree & D. Thomas, "MBSE to Incorporate Human Systems Integration Modelling," AIAA SciTech, Nashville, Tennessee, January 11-15, 2021. https://doi.org/10.2514/6.2021-0096

D. Nikitaev & D. Thomas, “In-Situ Propellant Infrastructure for Alternative Propellant Nuclear Thermal Propulsion Engines,” AIAA ASCEND, Las Vegas, Nevada, November 15-17, 2021.

N. Morris & D. Thomas, “ZBO Storage of Liquid Hydrogen Applied to the Mars Transfer Vehicle,” 72nd International Astronautical Congress, Dubai, October 25-29, 2021.

E. Wood & D. Thomas, “Power Generation Alternatives for a Nuclear Thermal Propulsion Engine,” 72nd International Astronautical Congress, Dubai, October 25-29, 2021.

D. Thomas, M. Houts, W. Walters, K. Hollingsworth, R. Frederick, & J. Cassibry, “Toward the Engineering Feasibility of the Centrifugal Nuclear Thermal Rocket,” 72nd International Astronautical Congress, Dubai, October 25-29, 2021.

D. Nikitaev & D. Thomas, “In-Situ Alternative Propellants for Nuclear Thermal Propulsion,” AIAA Propulsion and Energy Forum and Exposition, Denver, August 9-11, 2021.

D. Nikitaeva, D. Nikitaev, & D. Thomas, “Details of the Spacecraft Integrated System Model for Nuclear Thermal Propulsion Applications,” AIAA Propulsion and Energy Forum and Exposition, Denver, August 9-11, 2021.

D. Thomas, M. Houts, W. Walters, K. Hollingsworth, R. Frederick, & J. Cassibry, “Establishing the Feasibility of the Centrifugal Nuclear Thermal Rocket,” AIAA Propulsion and Energy Forum and Exposition, Denver, August 9-11, 2021.

E. Wood & D. Thomas, “Nuclear Thermal Propulsion Engine Minimally-Intrusive Power Generation Alternatives,” AIAA Propulsion and Energy Forum and Exposition, Denver, August 9-11, 2021.

S. Raghu & D. Thomas, “Liquid Propulsion: Modeling and Simulation of Liquid Propulsion Systems, Components, and Processes,” AIAA Propulsion and Energy Forum and Exposition, Denver, August 9-11, 2021.

S. Kumar, D. Thomas, & J. Cassibry, “Model-Based Approach for Conceptual Mission Design for NTP Enabled Robotic Missions,” AIAA Propulsion and Energy Forum and Exposition, Denver, August 9-11, 2021.

M. Tudor, D. Thomas, & G. Wang, “Analysis and Utility of a Structural Margin Based Design for Failure Prone Components in Liquid Rocket Engines,” AIAA Propulsion and Energy Forum and Exposition, Denver, August 9-11, 2021.

J. Keese & D. Thomas, “Liquid Propulsion System Testing Best Practices Approaches Applied to Nuclear Thermal Propulsion System Development,” 68th Joint Army Navy NASA Air Force (JANNAF) Joint Subcommittee Meeting, virtual, June 7-17, 2021.

D. Nikitaev and D. Thomas, “Alternative Propellants for Nuclear Thermal Propulsion,” 68th Joint Army Navy NASA Air Force (JANNAF) Joint Subcommittee Meeting, virtual, June 7-17, 2021.

D. Nikitaev & D. Thomas, “In-Situ Alternative Propellants for Nuclear Thermal Propulsion, Nuclear and Emerging Technologies for Space (NETS) 2021, virtual, April 26-30, 2021.

S. Kumar, D. Thomas, & J. Cassibry, “Decoding the Mission Design Problem for NTP Systems for Outer Planet Robotic Missions,” Nuclear and Emerging Technologies for Space (NETS) 2021, virtual, April 26-30, 2021.

N. Morris, D. Thomas, & K. Hollingsworth, “A Cool Model to Analyze Heat Deposition on MTV Propellant Tanks,” Nuclear and Emerging Technologies for Space (NETS) 2021, virtual, April 26-30, 2021.

E. Wood & D. Thomas, “Alternatives for Electrical Power Production from a Nuclear Thermal Propulsion Engine,” Nuclear and Emerging Technologies for Space (NETS) 2021. virtual, April 26-30, 2021.

S. Kumar, D. Thomas, J. Cassibry, “Nuclear Thermal Propulsion for Outer Planets Robotic Exploration,” 52nd Lunar and Planetary Science Conference, virtual, March 15–19, 2021.

A. Aueron & D. Thomas, "Mars Mission Architecture Decision through Value Models," Nuclear and Emerging Technologies for Space, American Nuclear Society Topical Meeting, Knoxville, Tennessee, April 6-9, 2020.

A. Aueron and D. Thomas, "Value Driven Mars Architecture Design," AIAA Propulsion and Energy Forum and Exposition, New Orleans, August 24-26, 2020. https://doi.org/10.2514/6.2020-3848

S. Kumar, D. Thomas, and J. Cassibry, "Preliminary Trajectory Design for Jupiter Rendezvous Mission Using Nuclear Thermal Propulsion," AIAA Propulsion and Energy Forum and Exposition, New Orleans, August 24-26, 2020. https://doi.org/10.2514/6.2020-3840

S. Kumar, D. Thomas, J. Cassibry, and R. Frederick, "Review of Nuclear Thermal Propulsion Technology for Deep Space Missions," AIAA Propulsion and Energy Forum and Exposition, New Orleans, August 24- 26, 2020. https://doi.org/10.2514/6.2020-3915

N. Morris and D. Thomas, "A Cool Model to Analyze Heat Deposition on MTV Propellant Tanks," AIAA Propulsion and Energy Forum and Exposition, New Orleans, August 24-26, 2020. DOI:10.1080/00295450.2020.1819157

N. Morris & D. Thomas, "Stay cool – Alternatives for Long Term Storage of Large Quantities of Liquid Hydrogen on a Mars Transfer Vehicle", Nuclear and Emerging Technologies for Space, American Nuclear Society Topical Meeting, Knoxville, Tennessee, April 6-9, 2020.

D. Nikitaev, D. Thomas, & J. Cassibry, "A Laboratory Test to Evaluate Seeded Hydrogen in a Nuclear Thermal Rocket Engine, Nuclear and Emerging Technologies for Space, American Nuclear Society Topical Meeting, Knoxville, Tennessee, April 6-9, 2020.

D. Nikitaev, S. Kumar, D. Thomas, & J. Cassibry, "Launch Vehicle Selection for Mars Transfer Vehicles Utilizing Seeded Hydrogen in a Nuclear Thermal Propulsion System," AIAA ASCEND, Las Vegas, Nevada, November 16-18, 2020. https://doi.org/10.2514/6.2020-4054

S. L. Raghu and D. Thomas, "Model Based FMEA (MBFMEA) generation for the RS-25 engine using SysML", AIAA Propulsion and Energy Forum and Exposition, New Orleans, August 24-26, 2020. https://doi.org/10.2514/6.2021-0305

I. Rountree, V. Lopez, & D. Thomas, "Change Management Processes in MBSE," 18th Conference on Systems Engineering Research, Redondo Beach, California, March 19-21, 2020.

E. Wood & D. Thomas, "Alternatives for Electrical Power Production from a Nuclear Thermal Propulsion Engine", Nuclear and Emerging Technologies for Space, American Nuclear Society Topical Meeting, Knoxville, Tennessee, April 6-9, 2020.

E. Wood, D. Thomas, and J. Cassibry, "Minimally-Intrusive Power Generation Alternatives from a Nuclear Thermal Propulsion Engine," AIAA Propulsion and Energy Forum and Exposition, New Orleans, August 24-26, 2020. https://doi.org/10.2514/6.2020-3844

A. Aueron & D. Thomas, "Trades on Densified Propellant for Nuclear Thermal Propulsion," Nuclear and Emerging Technologies for Space, American Nuclear Society Topical Meeting, Richland, Washington, February 25 – 28, 2019.

A. Aueron & D. Thomas, "Nuclear Thermal Propulsion Vehicle Scaling and the Importance of Densified Propellant," AIAA-2019-3942, AIAA Propulsion & Energy Forum, Indianapolis, Indiana, August 19-22, 2019. https://doi.org/10.2514/6.2019-3942

A. Aueron, D. Thomas, & P. Collopy, "The Value of Enhanced Delta V Capacity: A Europa Clipper Case Study," 70th International Astronautical Congress, Paper IAC-19,D2,8-A5.4,12,x51117, Washington, DC, October 21-25, 2019.

V. Lopez & D. Thomas, "Complexity Assessment Using SysML Models," 2019 Conference on Systems Engineering Research (CSER), Washington, DC, April 3-4, 2019. https://doi.org/10.1016/j.procs.2019.05.074

D. Nikitaev, "Air and Space Thermal Rocket Engine with Turbojet (ASTRET)," AIAA-2019-4393, AIAA Propulsion & Energy Forum, Indianapolis, Indiana, August 19-22, 2019. https://doi.org/10.2514/6.2019-4393

S. Rawlins & D. Thomas, "A Proposed Solution to Address Nuclear Thermal Propulsion Fuel Embrittlement and Cryogenic Hydrogen Requirements," Nuclear and Emerging Technologies for Space, American Nuclear Society Topical Meeting, Richland, Washington, February 25 – 28, 2019.

D. Thomas, A. Aueron, V. Lopez, and A. Bower, A. , "Virtual Systems Integration Applied to Advanced Space Systems," AIAA-2019-4053, AIAA Propulsion & Energy Forum, Indianapolis, Indiana, August 19-22, 2019. https://doi.org/10.2514/6.2019-4053

A. Aueron, Z. Thomas, & D. Thomas, "Mars Transport Optimization," Joint Army Navy NASA Air Force (JANNAF) Joint Subcommittee Meeting, Long Beach, California, May 21-24, 2018.

A. Aueron, D. Thomas, & J. Cassibry, "Analytical Radiation Attenuation and Heat Deposition Modeling for Conceptual Design of Nuclear Thermal Rockets," AIAA Propulsion & Energy Forum, Cincinnati, Ohio, July 9-11, 2018. https://doi.org/10.2514/6.2018-4954

A. Bower & D. Thomas, "Liquid Rocket Engine Production Process Modelling," Joint Army Navy NASA Air Force (JANNAF) Joint Subcommittee Meeting, Long Beach, California, May 21-24, 2018.

A. Bower & D. Thomas, "Creating an Affordability Model for the RS-25 Liquid Rocket Engine," AIAA Propulsion & Energy Forum, Cincinnati, Ohio, July 9-11, 2018.

M. Gethers & D. Thomas, "A Method for Robust Requirements Definition," 16th Conference on Systems Engineering Research (CSER), Charlottesville, Virginia, May 8-9, 2018. https://doi.org/10.1007/978-3-030-00114-8_30

M. Gethers & D. Thomas, "Utilization of Goal Function Trees for Robust Requirements Definition," INCOSE International Symposium, Washington, DC, July 7-12, 2018. https://doi.org/10.1002/j.2334-5837.2018.00500.x

V. Lopez & D. Thomas, "Complexity metrics suite for systems modelled using SysML," 16th Conference on Systems Engineering Research (CSER), Charlottesville, Virginia, May 8-9, 2018.

A. Aueron and D. Thomas, "Nuclear Thermal Propulsion System Modeling using Model Based Systems Engineering," Joint Army Navy NASA Airforce (JANNAF) In-Space Chemical Propulsion Technical Interchange Meeting, Huntsville, Alabama, April 4-6, 2017.

A. Aueron and D. Thomas, "Modeling Nuclear Thermal Propulsion with Model Based Systems Engineering," AIAA Space 2017 Conference & Exposition, Orlando, Florida, September 12-14, 2017.

E. Patterson and D. Thomas, "Human Mental Models and their effects on human and system interactions within Socio-Technical Systems," 15 th Conference on Systems Engineering Research, Los Angeles, California, March 23-25, 2017.

L. Walker & D. Thomas, "Integrated system modeling in SysML for Small Satellites," AIAA SciTech 2017, Grapevine, Texas, January 9-13, 2017. https://doi.org/10.2514/6.2017-1769

D. Thomas and B. Mesmer, "Virtual Systems Integration using Model Based Systems Engineering," AIAA Space 2016, Long Beach, California, September 13–16, 2016. https://doi.org/10.2514/6.2016-5311